In C/POSIX arithmetic, a leading 0 denotes an octal number, e.g.
010 == 8. But this is not a desirable feature as it can cause
problems with processing things like dates with a leading zero.
In ksh, you should use 8#10 instead ("10" with base 8).
It would be tolerable if ksh at least implemented it consistently.
But AT&T made an incredible mess of it. For anyone who is not
intimately familiar with ksh internals, it is inscrutable where
arithmetic evaluation special-cases a leading 0 and where it
doesn't. Here are just some of the surprises/inconsistencies:
1. The AT&T maintainers tried to honour a leading 0 inside of
((...)) and $((...)) and not for arithmetic contexts outside it,
but even that inconsistency was never quite consistent.
2. Since 2010-12-12, $((x)) and $(($x)) are different:
$ /bin/ksh -c 'x=010; echo $((x)) $(($x))'
10 8
That's a clear violation of both POSIX and the principle of
least astonishment. $((x)) and $(($x)) should be the same in
all cases.
3. 'let' with '-o letoctal' acts in this bizarre way:
$ set -o letoctal; x=010; let "y1=$x" "y2=010"; echo $y1 $y2
10 8
That's right, 'let y=$x' is different from 'let y=010' even
when $x contains the same string value '010'! This violates
established shell grammar on the most basic level.
This commit introduces consistency. By default, ksh now acts like
mksh and zsh: the octal leading zero is disabled in all arithmetic
contexts equally. In POSIX mode, it is enabled equally.
The one exception is the 'let' built-in, where this can still be
controlled independently with the letoctal option as before (but,
because letoctal is synched with posix when switching that on/off,
it's consistent by default).
We're also removing the hackery that causes variable expansions for
the 'let' builtin to be quietly altered, so that 'x=010; let y=$x'
now does the same as 'let y=010' even with letoctal on.
Various files:
- Get rid of now-redundant sh.inarith (shp->inarith) flag, as we're
no longer distinguishing between being inside or outside ((...)).
src/cmd/ksh93/sh/arith.c:
- arith(): Let disabling POSIX octal constants by skipping leading
zeros depend on either the letoctal option being off (if we're
running the "let" built-in") or the posix option being off.
- sh_strnum(): Preset a base of 10 for strtonll(3) depending on the
posix or letoctal option being off, not on the sh.inarith flag.
src/cmd/ksh93/include/argnod.h,
src/cmd/ksh93/sh/args.c,
src/cmd/ksh93/sh/macro.c:
- Remove astonishing hackery that violated shell grammar for 'let'.
src/cmd/ksh93/sh/name.c (nv_getnum()),
src/cmd/ksh93/sh/nvdisc.c (nv_getn()):
- Remove loops for skipping leading zeroes that included a broken
check for justify/zerofill attributes, thereby fixing this bug:
$ typeset -Z x=0x15; echo $((x))
-ksh: x15: parameter not set
Even if this code wasn't redundant before, it is now: sh_arith()
is called immediately after the removed code and it ignores
leading zeroes via sh_strnum() and strtonll(3).
Resolves: https://github.com/ksh93/ksh/issues/334
This commit fixes two file descriptor leaks in the hist built-in.
The bugfix for the first file descriptor leak was backported from
ksh2020. See:
https://github.com/att/ast/issues/872https://github.com/att/ast/commit/73bd61b5
Reproducer:
$ echo no
$ hist -s no=yes
The second file descriptor leak occurs after a substitution error
in the hist built-in (this leak wasn't fixed in ksh2020).
Reproducer:
$ echo no
$ ls /proc/$$/fd
$ hist -s no=yes
$ hist -s no=yes
$ ls /proc/$$/fd
src/cmd/ksh93/bltins/hist.c:
- Close leftover file descriptors when an error occurs and after
'hist -s' runs a command.
src/cmd/ksh93/tests/builtins.sh:
- Add two regression tests for both of the file descriptor leaks.
The --posix compliance option now disables the case-insensitive
special floating point constants Inf and NaN so that all case
variants of $((inf)) and $((nan)) refer to the variables by those
names as the standard requires. (BUG_ARITHNAN)
src/cmd/ksh93/sh/arith.c: arith():
- Only do case-insensitive checks for "Inf" and "NaN" if the POSIX
option is off.
ksh crashed after unsetting .sh.match and then matching a pattern:
$ unset .sh.match
$ [[ bar == ba* ]]
Memory fault
src/cmd/ksh93/sh/init.c: sh_setmatch():
- Do nothing if we cannot get an array pointer to SH_MATCHNOD.
Symptoms:
$ test \( string1 -a string2 \)
/usr/local/bin/ksh: test: argument expected
$ test \( string1 -o string2 \)
/usr/local/bin/ksh: test: argument expected
The parentheses should be irrelevant and this should be a test for
the non-emptiness of string1 and/or string2.
src/cmd/ksh93/bltins/test.c:
- b_test(): There is a block where the case of 'test' with five or
less arguments, the first and last one being parentheses, is
special-cased. The parentheses are removed as a workaround: argv
is increased to skip the opening parenthesis and argc is
decreased by 2. However, there is no corresponding increase of
tdata.av which is a copy of this function's argv. This renders
the workaround ineffective. The fix is to add that increase.
- e3(): Do not handle '!' as a negator if not followed by an
argument. This allows a right-hand expression that is equal to
'!' (i.e. a test for the non-emptiness of the string '!').
In ksh88, the test/[ built-in supported both the '<' and '>'
lexical sorting comparison operators, same as in [[. However, in
every version of ksh93, '<' does not work though '>' still does!
Still, the code for both is present in test_binop():
src/cmd/ksh93/bltins/test.c
548: case TEST_SGT:
549: return(strcoll(left, right)>0);
550: case TEST_SLT:
551: return(strcoll(left, right)<0);
Analysis: The binary operators are looked up in shtab_testops[] in
data/testops.c using a macro called sh_lookup, which expands to a
sh_locate() call. If we examine that function in sh/string.c, it's
easy to see that on systems using ASCII (i.e. all except IBM
mainframes), it assumes the table is sorted in ASCII order.
src/cmd/ksh93/sh/string.c
64: while((c= *tp->sh_name) && (CC_NATIVE!=CC_ASCII || c <= first))
The problem was that the '<' operator was not correctly sorted in
shtab_testops[]; it was sorted immediately before '>', but after
'='. The ASCII order is: < (60), = (61), > (62). This caused '<' to
never be found in the table.
The test_binop() function is also used by [[, yet '<' always worked
in that. This is because the parser has code that directly checks
for '<' and '>' within [[ (in sh/parse.c, lines 1949-1952).
This commit also adds '=~' to 'test', which took three lines of
code and allowed eliminating error handling in test_binop() as
test/[ and [[ now support the same binary ops. (re: fc2d5a60)
src/cmd/ksh93/*/*.[ch]:
- Rename a couple of very misleadingly named macros in test.h:
. For == and !=, the TEST_PATTERN bit is off for pattern compares
and on for literal string compares! Rename to TEST_STRCMP.
. The TEST_BINOP bit does not denote all binary operators, but
only the logical -a/-o ops in test/[. Rename to TEST_ANDOR.
src/cmd/ksh93/bltins/test.c: test_binop():
- Add support for =~. This is only used by test/[. The method is
implemented in two lines that convert the ERE to a shell pattern
by prefixing it with ~(E), then call test_strmatch with that
temporary string to match the ERE and update ${.sh.match}.
- Since all binary ops from shtab_testops[] are now accounted for,
remove unknown op error handling from this function.
src/cmd/ksh93/data/testops.c:
- shtab_testops[]:
. Correctly sort the '<' (TEST_SLT) entry.
. Remove ']]' (TEST_END). It's not an op and doesn't belong here.
- Update sh_opttest[] documentation with =~, \<, \>.
- Remove now-unused e_unsupported_op[] error message.
src/cmd/ksh93/sh/lex.c: sh_lex():
- Check for ']]' directly instead of relying on the removed
TEST_END entry from shtab_testops[].
src/cmd/ksh93/tests/bracket.sh:
- Add relevant tests.
src/cmd/ksh93/tests/builtins.sh:
- Fix an old test that globally deleted the 'test' builtin. Delete
it within the command substitution subshell only.
- Remove the test for non-support of =~ in test/[.
- Update the test for invalid test/[ op to use test directly.
POSIX requires
test "$a" -a "$b"
to return true if both $a and $b are non-empty, and
test "$a" -o "$b"
to return true if either $a or $b is non-empty.
In ksh, this fails if "$a" is '!' or '(' as this causes ksh to
interpret the -a and -o as unary operators (-a being a file
existence test like -e, and -o being a shell option test).
$ test ! -a ""; echo "$?"
0 (expected: 1/false)
$ set -o trackall; test ! -o trackall; echo "$?"
1 (expected: 0/true)
$ test \( -a \); echo "$?"
ksh: test: argument expected
2 (expected: 0/true)
$ test \( -o \)
ksh: test: argument expected
2 (expected: 0/true)
Unfortunately this problem cannot be fixed without risking breakage
in legacy scripts. For instance, a script may well use
test ! -a filename
to check that a filename is nonexistent. POSIX specifies that this
always return true as it is a test for the non-emptiness of both
strings '!' and 'filename'.
So this commit fixes it for POSIX mode only.
src/cmd/ksh93/bltins/test.c: e3():
- If the posix option is active, specially handle the case of
having at least three arguments with the second being -a or -o,
overriding their handling as unary operators.
src/cmd/ksh93/data/testops.c:
- Update 'test --man --' date and say that unary -a is deprecated.
src/cmd/ksh93/sh.1:
- Document the fix under the -o posix option.
- For test/[, explain that binary -a/-o are deprecated.
src/cmd/ksh93/tests/bracket.sh:
- Add tests based on reproducers in bug report.
Resolves: https://github.com/ksh93/ksh/issues/330
Stéphane Chazelas reported:
> As noted in this austin-group-l discussion[*] (relevant to this
> issue):
>
> $ ksh93u+m -c 'pwd; echo "$?" >&2; echo test; echo "$?" >&2' >&-
> 0
> 1
> /home/chazelas
>
> when stdout is closed, pwd does claim it succeeds (by returning a
> 0 exit status), while echo doesn't (not really relevant to the
> problem here, only to show it doesn't affect all builtins), and
> the output that pwd failed to write earlier ends up being written
> on stderr here instead of stdout upon exit (presumably) because
> of that >&2 redirection.
>
> strace shows ksh93 attempting write(1, "/home/chazelas\n", 15) 6
> times (1, the last one, successful).
>
> It gets even weirder when redirecting to a file:
>
> $ ksh93u+m -c 'pwd; echo "$?" >&2; echo test; echo "$?" > file' >&-
> 0
> $ cat file
> 1
> 1
> ome/chazelas
In my testing, the problem does not occur when closing stdout at
the start of the -c script itself (using redirect >&- or exec >&-);
it only occurs if stdout was closed before initialising the shell.
That made me suspect that the problem had to do with an
inconsistent file descriptor state in the shell. ksh uses internal
sh_open() and sh_close() functions, among others, to maintain that
state.
src/cmd/ksh93/sh/main.c: sh_main():
- If the shell is initialised with stdin, stdout or stderr closed,
then make the shell's file descriptor state tables reflect that
fact by calling sh_close() for the closed file descriptors.
This commit also improves the BUG_PUTIOERR fix from 93e15a30. Error
checking after sfsync() is not sufficient. For instance, on
FreeBSD, the following did not produce a non-zero exit status:
ksh -c 'echo hi' >/dev/full
even though this did:
ksh -c 'echo hi >/dev/full'
Reliable error checking requires not only checking the result of
every SFIO command that writes output, but also synching the buffer
at the end of the operation and checking the result of that.
src/cmd/ksh93/bltins/print.c:
- Make exitval variable global to allow functions called by
b_print() to set a nonzero exit status.
- Check the result of all SFIO output commands that write output.
- b_print(): Always sfsync() at the end, except if the s (history)
flag was given. This allows getting rid of the sfsync() call that
required the workaround introduced in 846ad932.
[*] https://www.mail-archive.com/austin-group-l@opengroup.org/msg08056.html
Resolves: https://github.com/ksh93/ksh/issues/314
Bug 1: POSIX requires numbers used as arguments for all the %d,
%u... in printf to be interpreted as in the C language, so
printf '%d\n' 010
should output 8 when the posix option is on. However, it outputs 10.
This bug was introduced as a side effect of a change introduced in
the 2012-02-07 version of ksh 93u+m, which caused the recognition
of leading-zero numbers as octal in arithmetic expressions to be
disabled outside ((...)) and $((...)). However, POSIX requires
leading-zero octal numbers to be recognised for printf, too.
The change in question introduced a sh.arith flag that is set while
we're processing a POSIX arithmetic expression, i.e., one that
recognises leading-zero octal numbers.
Bug 2: Said flag is not reset in a command substitution used within
an arithmetic expression. A command substitution should be a
completely new context, so the following should both output 10:
$ ksh -c 'integer x; x=010; echo $x'
10 # ok; it's outside ((…)) so octals are not recognised
$ ksh -c 'echo $(( $(integer x; x=010; echo $x) ))'
8 # bad; $(comsub) should create new non-((…)) context
src/cmd/ksh93/bltins/print.c: extend():
- For the u, d, i, o, x, and X conversion modifiers, set the POSIX
arithmetic context flag before calling sh_strnum() to convert the
argument. This fixes bug 1.
src/cmd/ksh93/sh/subshell.c: sh_subshell():
- When invoking a command substitution, save and unset the POSIX
arithmetic context flag. Restore it at the end. This fixes bug 2.
Reported-by: @stephane-chazelas
Resolves: https://github.com/ksh93/ksh/issues/326
When invoking a script without an interpreter (#!hashbang) path,
ksh forks, but there is no exec syscall in the child. The existing
command line is overwritten in fixargs() with the name of the new
script and associated arguments. In the generic/fallback version of
fixargs() which is used on Linux and macOS, if the new command line
is longer than the existing one, it is truncated. This works well
when calling a script with a shorter name.
However, it generates a misleading name in the common scenario
where a script is invoked from an interactive shell, which
typically has a short command line. For instance, if "/tmp/script"
is invoked, "ksh" gets replaced with "/tm" in "ps" output.
A solution is found in the fact that, on these systems, the
environment is stored immediately after the command line arguments.
This space can be made available for use by a longer command line
by moving the environment strings out of the way.
src/cmd/ksh93/sh/main.c: fixargs():
- Refactor BSD setproctitle(3) version to be more self-contained.
- In the generic (Linux/macOS) version, on init (i.e. mode==0), if
the command line is smaller than 128 bytes and the environment
strings have not yet been moved (i.e. if they still immediately
follow the command line arguments in memory), then strdup the
environment strings, pointing the *environment[] members to the
new strings and adding the length of the strings to the maximum
command line buffer size.
Reported-by: @gkamat
Resolves: https://github.com/ksh93/ksh/pull/300
ksh93 currently has three command substitution mechanisms:
- type 1: old-style backtick comsubs that use a pipe;
- type 3: $(modern) comsubs that use a temp file, currently with
fallback to a pipe if a temp file cannot be created;
- type 2: ${ shared-state; } comsubs; same as type 3, but shares
state with parent environment.
Type 1 is buggy. There are at least two reproducers that make it
hang. The Red Hat patch applied in 4ce486a7 fixed a hang in
backtick comsubs but reintroduced another hang that was fixed in
ksh 93v-. So far, no one has succeeded in making pipe-based comsubs
work properly.
But, modern (type 3) comsubs use temp files. How does it make any
sense to have two different command substitution mechanisms at the
execution level? The specified functionality between backtick and
modern command substitutions is exactly the same; the difference
*should* be purely syntactic.
So this commit removes the type 1 comsub code at the execution
level, treating them all like type 3 (or 2). As a result, the
related bugs vanish while the regression tests all pass.
The only side effect that I can find is that the behaviour of bug
https://github.com/ksh93/ksh/issues/124 changes for backtick
comsubs. But it's broken either way, so that's neutral.
So this commit can now be added to my growing list of ksh93 issues
fixed by simply removing code.
src/cmd/ksh93/sh/xec.c:
- Remove special code for type 1 comsubs from iousepipe(),
sh_iounpipe(), sh_exec() and _sh_fork().
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/sh/subshell.c:
- Remove pipe support from sh_subtmpfile(). This also removes the
use of a pipe as a fallback for $(modern) comsubs. Instead, panic
and error out if temp file creation fails. If the shell cannot
create a temporary file, there are fatal system problems anyway
and a script should not continue.
- No longer pass comsub type to sh_subtmpfile().
All other changes:
- Update sh_subtmpfile() calls.
src/cmd/ksh93/tests/subshell.sh:
- Add two regression tests based on reproducers from bug reports.
Resolves: https://github.com/ksh93/ksh/issues/305
Resolves: https://github.com/ksh93/ksh/issues/316
Bug: [[ ! ! 1 -eq 1 ]] returns false, but should return true.
This bug was reported for bash, but ksh has it too:
https://lists.gnu.org/archive/html/bug-bash/2021-06/msg00006.html
Op 24-05-21 om 17:47 schreef Chet Ramey:
> On 5/22/21 2:45 PM, Vincent Menegaux wrote:
>> Previously, these commands:
>>
>> [[ ! 1 -eq 1 ]]; echo $?
>> [[ ! ! 1 -eq 1 ]]; echo $?
>>
>> would both result in `1', since parsing `!' set CMD_INVERT_RETURN
>> instead of toggling it.
>
> Interestingly, ksh93 produces the same result as bash. I agree
> that it's more intuitive to toggle it.
Also interesting is that '!' as an argument to the simple
'test'/'[' command does work as expected (on both bash and ksh93):
'test ! ! 1 -eq 1' and '[ ! ! 1 -eq 1 ]' return 0/true.
Even the man page for [[ is identical for bash and ksh93:
| ! expression
| True if expression is false.
This suggests it's supposed to be a logical negation operator, i.e.
'!' is implicitly documented to negate another '!'. Bolsky & Korn's
1995 ksh book, p. 167, is slightly more explicit about it:
"! test-expression. Logical negation of test-expression."
I also note that multiple '!' negators in '[[' work as expected on
mksh, yash and zsh.
src/cmd/ksh93/sh/parse.c: test_primary():
- Fix bitwise logic for '!': xor the TNEGATE bit into tretyp
instead of or'ing it, which has the effect of toggling it.
This regression also exists on ksh 93v- and ksh2020, from which it
was backported.
Reproducer:
$ (fn() { true; }; fn >/dev/null/ne; true) 2>/dev/null; echo $?
1
Expected output: 0 (as on ksh 93u+).
FreeBSD sh and NetBSD sh are the only other known shells that share
this behaviour. POSIX currently allows both behaviours, but may
require the ksh 93u+ behaviour in future. In any case, this causes
an incompatibility with established ksh behaviour that could easily
break existing ksh scripts.
src/cmd/ksh93/sh/xec.c: sh_exec():
- Commit 23f2e23 introduced a check for jmpval > SH_JMPIO (5).
When a function call pushes context for a redirection, this is
done with the jmpval exit value of SH_JMPCMD (6). Change that to
SH_JMPIO to avoid triggering that check.
src/cmd/ksh93/tests/exit.sh:
- Add regression tests for exit behaviour on various kinds of
shell errors as listed in the POSIX standard, including an error
in a redirection of a function call.
Fixes: https://github.com/ksh93/ksh/issues/310
Problem:
$ exec ksh
$ echo $SHLVL
2
$ exec ksh
$ echo $SHLVL
3
$ exec ksh
$ echo $SHLVL
4
...etc. SHLVL is supposed to acount the number of shell processes
that you need to exit before you get logged out. Since ksh was
replacing itself with a new shell in the same process using 'exec',
SHLVL should not increase.
src/cmd/ksh93/bltins/misc.c: b_exec():
- When about to replace the shell and we're not in a subshell,
decrease SHLVL to cancel out a subsequent increase by the
replacing shell. Bash and zsh also do this.
Since a command substitution no longer forks on non-permanently
redirecting standard output within it for a specific command,
test -t 1, [ -t 1 ], and [[ -t 1 ]] broke as follows:
v=$(test -t 1 >/dev/tty && echo ok) did not assign 'ok' to v.
This is because the assumption in tty_check() that standard output
is never on a terminal in a non-forked command substitution, added
in 55f0f8ce, was made invalid by 090b65e7.
src/cmd/ksh93/edit/edit.c: tty_check():
- Implement a new method. Return false if the file descriptor
stream is of type SF_STRING, which is the case for non-forked
command substitutions -- it means the sfio stream writes directly
into a memory area. This can be checked with the sfset(3)
function (see src/lib/libast/man/sfio.3). To avoid a segfault
when accessing sh.sftable, we need to validate the FD first.
src/cmd/ksh93/tests/pty.sh:
- Add the above reproducer.
In May 2020, when every KornShell (ksh93) development project was
abandoned, development was rebooted in a new fork based on the last
stable AT&T version: ksh 93u+. Now, one year and hundreds of bug
fixes later, the first beta version is ready, and KornShell lives
again. This new fork is called ksh 93u+m as a permanent nod to its
origin; a standard semantic version number is added starting at
1.0.0-beta.1. Please test the beta and report any bugs you find,
or help us fix known bugs.
src/cmd/ksh93/data/math.tab:
- Added exp10().
- Remove int() as being an alias to floor().
- Created entries for local float() and local int() which are
defined in features/math.sh.
src/cmd/ksh93/features/math.sh:
- Backport floor() and int() related code from ksh93v-.
src/cmd/ksh93/sh.1:
- Sync man page to math.tab's potential functions.
BUG 1: Though 'command' is specified/documented as a regular
builtin, preceding assignments survive the invocation (as with
special or declaration builtins) if 'command' has no command
arguments in these cases:
$ foo=wrong1 command; echo $foo
wrong1
$ foo=wrong2 command -p; echo $foo
wrong2
$ foo=wrong3 command -x; echo $foo
wrong3
Analysis: sh_exec(), case TCOM (simple command), contains the
following loop that skips over 'command' prefixes, preparsing any
options and remembering the offset in the 'command' variable:
src/cmd/ksh93/sh/xec.c
1059 while(np==SYSCOMMAND || !np && com0
&& nv_search(com0,shp->fun_tree,0)==SYSCOMMAND)
1060 {
1061 register int n = b_command(0,com,&shp->bltindata);
1062 if(n==0)
1063 break;
1064 command += n;
1065 np = 0;
1066 if(!(com0= *(com+=n)))
1067 break;
1068 np = nv_bfsearch(com0, shp->bltin_tree, &nq, &cp);
1069 }
This skipping is not done if the preliminary b_command() call on
line 1061 (with argc==0) returns zero. This is currently the case
for command -v/-V, so that 'command' is treated as a plain and
regular builtin for those options.
The cause of the bug is that this skipping is even done if
'command' has no arguments. So something like 'foo=bar command' is
treated as simply 'foo=bar', which of course survives.
So the fix is for b_command() to return zero if there are no
arguments. Then b_command() itself needs changing to not error out
on the second/main b_command() call if there are no arguments.
src/cmd/ksh93/bltins/whence.c: b_command():
- When called with argc==0, return a zero offset not just for -v
(X_FLAG) or -V (V_FLAG), but also if there are no arguments left
(!*argv) after parsing options.
- When called with argc>0, do not issue a usage error if there are
no arguments, but instead return status 0 (or, if -v/-V was given,
status 2 which was the status of the previous usage message).
This way, 'command -v $emptyvar' now also works as you'd expect.
BUG 2: 'command -p' sometimes failed after executing certain loops.
src/cmd/ksh93/sh/path.c: defpath_init():
- astconf() returns a pointer to memory that may be overwritten
later, so duplicate the string returned. Backported from ksh2020.
(re: f485fe0f, aa4669ad, <https://github.com/att/ast/issues/959>)
src/cmd/ksh93/tests/builtins.sh:
- Update the test for BUG_CMDSPASGN to check every variant of
'command' (all options and none; invoking/querying all kinds of
command and none) with a preceding assignment. (re: fae8862c)
This also covers bug 2 as 'command -p' was failing on macOS prior
to the fix due to a loop executed earlier in another test.
This PR corrects #168 for indexed arrays having more than one
level. Turns out ksh was only keeping track of the subscript number
for assignment in lvalue's nosub variable. By saving the actual
subscript reference, the result can be assigned to its proper
destination instead of putting the result into the last looked
value or subscript location.
src/cmd/ksh93/include/streval.h: struct lval:
- Create a new pointer named sub to hold the reference that nosub
describes.
src/cmd/ksh93/sh/arith.c: arith():
- Adjust LOOKUP: for lvalue ARITH_ASSIGNOP operations on indexed
arrays to save the np of the destination subscript for later use.
- Adjust ASSIGN: to act when lvalue's nosub > 0 which happens as
the last step in the arithmetic parsing loop for assignment
operations. Only indexed arrays will have a nosub value > 0. All
others have a nosub of 0 unless they are involved in a unary
operation (++, --) which sets nosub to -1. All said in the
context of assignment operations like (( arr[0][1] += 1 )).
src/cmd/ksh93/sh/streval.c:
- Initialize the new sub pointer to 0.
src/cmd/ksh93/tests/arrays2.sh:
- Created a few multidimensional indexed array tests for assignment
operations like += as an example.
Resolves: https://github.com/ksh93/ksh/issues/168
Following the resolution of Austin Group bug 1393[*] that is set to
be included in the next version of the POSIX standard, the
'command' prefix in POSIX mode (set -o posix) no longer disables
the declaration properties of declaration built-ins.
[*] https://austingroupbugs.net/view.php?id=1393
src/cmd/ksh93/sh/parse.c: lex():
- Skip the 'command' prefix even in POSIX mode so that any
declaration commands prefixed by it are treated as such in xec.c
(sh_exec()).
src/cmd/ksh93/sh/xec.c: sh_exec():
- The foregoing change reintroduced a variant of BUG_CMDSPEXIT: the
shell exits on something like 'command export readonlyvar=foo'.
This now fixes that bug for both POSIX and non-POSIX mode. When
calling nv_setlist() to process true shell assignments, and there
is a 'command' prefix, push a shell context and use sigsetjmp to
intercept any errors in assignments and stop the shell exiting.
src/cmd/ksh93/tests/builtins.sh:
- Borrow the BUG_CMDSPEXIT regression test from modernish and adapt
it for ksh. (I'm the author so yes, I can do this.) Original:
https://github.com/modernish/modernish/blob/ae8fe9c3/lib/modernish/tst/builtin.t#L80-L109
This fixes the following:
1. Using $RANDOM in a virtual/non-forked subshell no longer
influences the reproducible $RANDOM sequence in the parent
environment.
2. When invoking a subshell $RANDOM is now re-seeded (as mksh and
bash do) so that invocations in repeated subshells (including
forked subshells) longer produce identical sequences by default.
3. Program flow corruption that occurred in scripts on executing
( ( simple_command & ) ).
src/cmd/ksh93/include/variables.h:
- Move 'struct rand' here as it will be needed in subshell.c. Add
rand_seed member to save the pseudorandom generator seed. Remove
the pointer to the shell state as it's redundant.
src/cmd/ksh93/sh/init.c:
- put_rand(): Store given seed in rand_seed while calling srand().
No longer pointlessly limit the number of possible seeds with the
RANDMASK bitmask (that mask is to limit the values to 0-32767,
it should not limit the number of possible sequences to 32768).
- nget_rand(): Instead of using rand(), use rand_r() to update the
random_seed value. This makes it possible to save/restore the
current seed of the pseudorandom generator.
- Add sh_reseed_rand() function that reseeds the pseudorandom
generator by calling srand() with a bitwise-xor combination of
the current PID, the current time with a granularity of 1/10000
seconds, and a sequence number that is increased on each
invocation.
- nv_init(): Set the initial seed using sh_reseed_rand() here
instead of in sh_main(), as this is where the other struct rand
members are initialised.
src/cmd/ksh93/sh/main.c: sh_main():
- Remove the srand() call that was replaced by the sh_reseed_rand()
call in init.c.
src/cmd/ksh93/sh/subshell.c: sh_subshell():
- Upon entering a virtual subshell, save the current $RANDOM seed
and state, then reseed $RANDOM for the subshell.
- Upon exiting a virtual subshell, restore $RANDOM seed and state
and reseed the generator using srand() with the restored seed.
src/cmd/ksh93/sh/xec.c: sh_exec():
- When optimizing out a subshell that is the last command, still
act like a subshell: reseed $RANDOM and increase ${.sh.subshell}.
- Fix a separate bug discovered while implementing this. Do not
optimize '( simple_command & )' when in a virtual subshell; doing
this causes program flow corruption.
- When optimizing '( simple_command & )', also reseed $RANDOM and
increment ${.sh.subshell}.
src/cmd/ksh93/tests/subshell.sh,
src/cmd/ksh93/tests/variables.sh:
- Add various tests for all of the above.
Co-authored-by: Johnothan King <johnothanking@protonmail.com>
Resolves: https://github.com/ksh93/ksh/issues/285
The following problems remained:
$ var=x; echo ${var:-'{}'}
x}
$ var=; echo ${var:+'{}'}
}
src/cmd/ksh93/sh/macro.c: varsub():
- Use the new ST_MOD1 state table to skip over ${var-'foo'}, etc.
instead of ST_QUOTE. In ST_MOD1 the ' is categorised as S_LIT
which causes the single quotes to be skipped over correctly.
See d087b031 for more info.
src/cmd/ksh93/tests/quoting2.sh:
- Add tests for this remaining bug.
- Make the new test xtrace-proof.
Resolves: https://github.com/ksh93/ksh/issues/290 (again)
The code contains various checks to see if a subshell needs to
fork, like this one in the ulimit builtin:
if(shp->subshell && !shp->subshare)
sh_subfork();
All checks of this form are fatally broken, as each one of them
causes shared-state command substitutions to ignore parent virtual
subshells.
Currently the only feasible way to fix this is to fork a virtual
subshell before executing a shared-state command substitution in
it. In the long term I think shared-state command substitutions
should probably be redesigned to disassociate them completely from
the virtual subshell mechanism.
src/cmd/ksh93/sh/macro.c: comsubst():
- If we're in a non-subshare virtual subshell, fork it before
entering a type 2 (subshare) command substitution.
src/cmd/ksh93/sh/subshell.c:
- sh_assignok(): Remove subshare fix from 911d6b06 as it's
redundant now that the parent of a subshare is never a virtual
subshell. Go back to not doing anything if the current "subshell"
is a subshare.
- sh_subtracktree(), sh_subfuntree(): Similarly, remove the
now-redundant subshare fixes from 13c57e4b.
src/cmd/ksh93/sh/xec.c: sh_exec():
- Fix a separate bug: only fork a virtual subshell before running a
background job if that "subshell" is not a subshare.
src/cmd/ksh93/tests/subshell.sh:
- Add test for bug fixed in xec.c.
- Add tests for 'ulimit', 'builtin' and 'exec' run in subshare
within subshell -- all commands that use checks of the form
'if(sh.subshell && !sh.subshare) sh_subfork();'.
Resolves: https://github.com/ksh93/ksh/issues/289
This avoids splitting on quoted whitespace when extracting words
from the command history using the emacs M-. or vi _ command.
Example: if the prior command is
$ ls Stairway\ To\ Heaven.mp3
then, M-. in Emacs editing mode (and _ in vi mode) now inserts
Stairway\ To\ Heaven.mp3 instead of Heaven.mp3. The behavior is
similar for 'Stairway To Heaven.mp3' and "Stairway To Heaven.mp3".
src/cmd/ksh93/edit/history.c: hist_word():
- Skip over single-quoted and double-quoted strings and
backslash-escaped characters.
src/cmd/ksh93/tests/pty.sh:
- Add regression test for this feature in vi mode. Since emacs and
vi both use the same code for this, that should be good enough.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
The referenced commit introduced the following bug:
> The closing quote does not appear to be registering during the
> parse of the following:
>
> echo ${var:+'{}'}
>
> Within a script, this will result in:
>
> syntax error at line 1: `'' unmatched
src/cmd/ksh93/data/lexstates.c,
src/cmd/ksh93/include/lexstates.h:
- Add new ST_MOD1 state table that is a copy of ST_QUOTE, but adds
a special meaning (ST_LIT) for the single quote (position 39).
src/cmd/ksh93/sh/lex.c: sh_lex():
- For parameter expansion operators with old-style quoting
(S_MOD1), use the new ST_MOD1 state table instead of ST_QUOTE.
This causes single quotes within them to be processed properly.
src/cmd/ksh93/tests/quoting2.sh:
- Add tests.
Thanks to @gkamat for the bug report.
Resolves: https://github.com/ksh93/ksh/issues/290
Previously, command substitutions executed as virtual subshells
were always forked if any command was run within them that
redireceted standard output, even if the redirection was local to
that command.
Commit 500757d7 removed the check for a shared-state command
substitution (subshare), so introduced a bug where even that would
fork, causing it to stop sharing its state.
We can further improve on that fix by only forking if the
redirection is permanent as with `exec` or `redirect`. There should
be no need to do that if the redirection is local to a command run
within the command substitution, as the file descriptor is restored
when that command finishes, which is still within the command
substitution.
src/cmd/ksh93/sh/io.c: sh_redirect():
- Only fork upon redirecting stdout if the virtual subshell is a
command substitution, and if the redirection is permanent
(flag==1 or flag==2).
Noteworthy changes:
- The man pages have been updated to fix a ton of instances of
runaway underlining (this was done with `sed -i 's/\\f5/\\f3/g'`
commands). This commit dramatically increased in size because
of this change.
- The documentation for spawnveg(3) has been extended with
information about its usage of posix_spawn(3) and vfork(2).
- The documentation for tmfmt(3) has been updated with the changes
previously made to the man pages for the printf and date builtins
(though the latter builtin is disabled by default).
- The shell's tracked alias tree (hash table) is now documented in
the shell(3) man page.
- Removed the commented out regression test for an ERRNO variable
as the COMPATIBILITY file states it was removed in ksh93.
There is a TODO note in variables.sh that notes the value of LINENO
is wrong after a virtual subshell. The following script should
print '6', but the bug causes it to print '1' instead:
$ cat /tmp/lineno
#!/bin/ksh
(
unset LINENO
:
)
echo $LINENO
This bug started to occur after the bugfix applied in 7b994b6a.
However, that commit is not where the cause of bug was (when that
bugfix is applied to ksh versions 2008-07-25 through 2012-01-01,
$LINENO works fine). Rather, the cause of this bug was introduced
in 93u+ 2012-02-29. In that version, the mp->nvfun pointer was only
copied from np->nvfun if the variable can be freed from memory.
This is what caused 7b994b6a to break $LINENO in subshells, so to
fix this bug the mp->nvfun and np->nvfun must point to the same
object, even when the variable isn't freed from memory.
src/cmd/ksh93/sh/subshell.c: nv_restore():
- Always copy the np->nvfun pointer to mp->nvfun. To prevent
crashes, the value of np->nvfun->nofree is set to the value given
by the nofree variable, which is set before _nv_unset. See also
commit 7e7f1372, which fixed a crash that happened because
_nv_unset discards the NV_NOFREE flag.
src/cmd/ksh93/tests/variables.sh:
- Remove the workaround for LINENO after a virtual subshell.
- Add a regression test for the value of LINENO when unset in a
virtual subshell, then used after the subshell. Note that before
commit 997ad43b LINENO's value was corrupted after being unset in
a subshell, so the test checks for corruption of the LINENO
variable (in prior commits LINENO was set to '49' because of the
previous bug).
The commands within a process substitution used as an argument to a
redirection (e.g. < <(...) or > >(...)) are simply not included in
parse trees dumped by shcomp. This can be verified with a command
like hexdump -C. As a result, these process substitutions do not
work when running a bytecode-compiled shell script.
The fix is surprisingly simple. A process substitution is encoded
as a complete parse tree. When used with a redirection, that parse
tree is used as the file name for the redirection. All we need to
do is treat the "file name" as a parse tree instead of a string if
flags indicate a process substitution.
A process substitution is detected by the struct ionod field
'iofile'. Checking the IOPROCSUB bit flag is not enough. We also
need to exclude the IOLSEEK flag as that form of redirection may
use the IOARITH flag which has the same bit value as IOPROCSUB (see
include/shnodes.h).
src/cmd/ksh93/sh/tdump.c: p_redirect():
- Call p_tree() instead of p_string() for a process substitution.
src/cmd/ksh93/sh/trestore.c: r_redirect():
- Call r_tree() instead of r_string() for a process substitution.
src/cmd/ksh93/include/version.h:
- Bump the shcomp binary header version as this change is not
backwards compatible; previous trestore.c versions don't know how
to read the newly compiled process substitutions and would crash.
src/cmd/ksh93/tests/io.sh:
- Add test.
src/cmd/ksh93/tests/builtins.sh,
src/cmd/ksh93/tests/options.sh:
- Revert shcomp workarounds. (re: 6701bb30)
Resolves: https://github.com/ksh93/ksh/issues/165
Johnothan King writes:
> There are two regressions related to how ksh handles syntax
> errors in the .kshrc file. If ~/.kshrc or the file pointed to by
> $ENV have a syntax error, ksh exits during startup. Additionally,
> the error message printed is incorrect:
>
> $ cat /tmp/synerror
> ((
> echo foo
>
> # ksh93u+m
> $ ENV=/tmp/synerror arch/*/bin/ksh -ic 'echo ${.sh.version}'
> /tmp/synerror: syntax error: `/t/tmp/synerror' unmatched
>
> # ksh93u+
> $ ENV=/tmp/synerror ksh93u -ic 'echo ${.sh.version}'
> /tmp/synerror: syntax error: `(' unmatched
> Version AJM 93u+ 2012-08-01
>
> The regression that causes the incorrect error message was
> introduced by commit cb67a01. The other bug that causes ksh to
> exit on startup was introduced by commit ceb77b1.
src/cmd/ksh93/sh/lex.c: fmttoken():
- Call stakfreeze(0) to terminate a possible unterminated previous
stack item before writing the token string onto the stack. This
fixes the bug with garbage in a syntax error message.
src/cmd/ksh93/sh/main.c: exfile():
- Revert Red Hat's ksh-20140801-diskfull.patch applied in ceb77b13.
This fixes the bug with interactive ksh exiting on syntax error
in a profile script. Testing by @JohnoKing showed the patch is no
longer necessary to fix a login crash on disk full, as commit
970069a6 (which applied Red Hat patches ksh-20120801-macro.patch
and ksh-20120801-fd2lost.patch) also fixes that crash.
src/cmd/ksh93/README:
- Fix typos. (re: fdc08b23)
Co-authored-by: Johnothan King <johnothanking@protonmail.com>
Resolves: https://github.com/ksh93/ksh/issues/281
While automagically importing/exporting ksh variable attributes via
the environment is probably a misfeature in general (now disabled
for POSIX standard mode), doing so with the readonly attribute is
particularly problematic. Scripts can take into account the
possibility of importing unwanted attributes by unsetting or
typesetting variables before using them. But there is no way for a
script to get rid of an unwanted imported readonly variable. This
is a possible attack vector with no possible mitigation.
This commit blocks both the import and the export of the readonly
attribute through the environment. I consider it a security fix.
src/cmd/ksh93/sh/init.c: env_import_attributes():
- Clear NV_RDONLY from imported attributes before applying them.
src/cmd/ksh93/sh/name.c: sh_envgen():
- Remove NV_RDONLY from bitmask defining attributes to export.
This commit fixes three problems with getconf pathbound builtin:
1. The -l/--lowercase option did not change all variable names to
lower case.
2. The -q/--quote option now quotes all string values. Previously,
it only quoted string values that had a space or other
non-shellsafe character.
3. The -c/--call, -n/--name and -s/--standard options matched all
variable names provided by 'getconf -a', even if none were
actual matches.
Additionally, references to the confstr and sysconf functions have
been updated to reference section 3 of the man pages instead of
section 2.
src/lib/libast/port/astconf.c:
- Previously, only values that had spaces in them were quoted. Change
that behavior to quote all string values by using the FMT_ALWAYS
flag. Bug report: https://github.com/att/ast/issues/1173
- Not all variable names were printed in lowercase by 'getconf -l'.
Fix it by adding a few missing instances of fmtlower.
Bug report: https://github.com/att/ast/issues/1171
- Add the missing code to the '#if _pth_getconf_a' block to handle
-c/-n/-s while parsing the OS's native 'getconf -a' output. This
approach reuses code for name matching from other parts of
astconflist(). Resolves: https://github.com/ksh93/ksh/issues/279
src/lib/libcmd/getconf.c:
- Update the documentation to note the -q flag only quotes strings.
src/cmd/ksh93/tests/bulitins.sh:
- Add regression tests for the getconf bugs fixed in this commit.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
Accessing t->tre.treio for every sh_exec() run is invalid because
't' is of type Shnode_t, which is a union that can contain many
different kinds of structs. As all members of a union occupy the
same address space, only one can be used at a time. Which member is
valid to access depends on the node type sh_exec() was called with.
The invalid access triggered a crash on 32-bit systems when
executing an arithmetic command like ((x=1)).
The t->tre.treio union member should be accessed for a simple
command (case TCOM in sh_exec()). The fix is also needed for
redirections attached to blocks (case TSETIO) in which case the
union member to use is t->fork.forkio.
src/cmd/ksh93/sh/xec.c:
- Add check_exec_optimization() function that checks for all the
conditions where the exec optimisation should not be done. For
redirections we need to loop through the whole list to check for
an IOREWRITE (<>;) one.
- sh_exec(): case TCOM (simple command): Only bother to call
check_exec_optimization() if there are either command arguments
or redirections (IOW: don't bother for bare variable
assignments), so move it to within the if(io||argn) block.
- sh_exec(): case TSETIO: This needs a similar fix. To avoid the
optimization breaking again if the last command is a subshell
with a <>; redirection attached, we need to not only set execflg
to 0 but also clear the SH_NOFORK state bit from the 'flags'
variable which is passed on to the recursive sh_exec() call.
src/cmd/ksh93/tests/io.sh:
- Update and expand tests. Add tests for redirections attached to
simple commands (TCOM) and various kinds of code block (TSETIO).
Co-authored-by: Johnothan King <johnothanking@protonmail.com>
Resolves: https://github.com/ksh93/ksh/issues/278
Immediately after tab-completing the name of a directory, it is
not possible to type digits after the slash; ksh eats them as it
parses them as a menu selection for a nonexistent menu.
Reproducer:
$ mkdir -p emacstest/123abc
$ cd emacste[tab]123abc
Actual results:
$ cd emacstest/abc
Expected results:
$ cd emacstest/123abc
Workarounds are to press a non-numeric key followed by backspace,
or hit [tab] again to get a list of options.
Originally reported by Arnon Weinberg, 2012-12-23 07:15:19 UTC, at:
https://bugzilla.redhat.com/889745
The fix had been partially backported from ksh 93v- by AT&T
(16e4824c), which made things worse, so it was reverted (e8b3274a).
This commit backports a slightly edited version of the complete
fix. Thanks to @JohnoKing for finding the correct code. Discussion:
https://github.com/ksh93/ksh/issues/198#issuecomment-820178514
src/cmd/ksh93/edit/emacs.c: escape():
- Backport the fix for this bug that was implemented in ksh 93v-
alpha 2013-10-10. Immediately after a slash, do not stay in "\"
mode (file name completion) and reset the tab count.
src/cmd/ksh93/tests/pty.sh:
- Test the fix.
Resolves: https://github.com/ksh93/ksh/issues/198
The <>; operator doesn't work correctly if it's used as the last
command of a -c script. Reproducer:
$ echo test > a; ksh -c 'echo x 1<>; a'; cat a
x
st
This bug is caused by ksh running the last command of -c scripts
with execve(2) instead of posix_spawn(3) or fork(2). The <>;
operator is noted by the man page as being incompatible with the
exec builtin (see also the ksh93u+ man page), so it's not
surprising this bug occurs when ksh runs a command using execve:
> <>;word cannot be used with the exec and redirect built-ins.
The ksh2020 fix simply removed the code required for ksh to use
this optimization at all. It's not a performance friendly fix and
only papers over the bug, so this commit provides a better fix.
This bug was first reported at:
https://github.com/att/ast/issues/9
In addition, this commit re-enables the execve(2) optimization for
the last command for scripts loaded from a file. It was enabled in
in older ksh versions, and was only disabled in interactive shells:
https://github.com/ksh93/ast-open-history/blob/2011-06-30/src/cmd/ksh93/sh/main.c#L593-L599
It was changed on 2011-12-24 to only be used for -c scripts:
https://github.com/ksh93/ast-open-history/blob/2011-12-24/src/cmd/ksh93/sh/main.c#L593-L599
We think there is no good reason why scripts loaded from a file
should be optimised less than scripts loaded from a -c argument.
They're both scripts; there's no essential difference between them.
So this commit reverts that change. If there is a bug left in the
optimization after this fix, this revert increases the chance of
exposing it so that it can be fixed.
src/cmd/ksh93/sh/xec.c:
- The IOREWRITE flag is set when handling the <>; operator, so to
fix this bug, avoid exec'ing the last command if it uses <>;. See
also commit 17ebfbf6, which fixed another issue related to the
execve optimization.
src/cmd/ksh93/tests/io.sh:
- Enable a regression test that was failing because of this bug.
- Add the reproducer from https://github.com/att/ast/issues/9 as a
regression test.
src/cmd/ksh93/sh/main.c:
- Only avoid the non-forking optimization in interactive shells.
src/cmd/ksh93/tests/signal.sh:
- Add an extra comment to avoid the non-forking optimization in the
regression test for rhbz#1469624.
- If the regression test for rhbz#1469624 fails, show the incorrect
exit status in the error message.
src/cmd/ksh93/tests/builtins.sh,
src/cmd/ksh93/tests/options.sh:
- This bugfix was causing the options regression test to segfault
when run under shcomp. The cause is the same as
<https://github.com/ksh93/ksh/issues/165>, so as a workaround,
avoid parsing process substitutions with shcomp until that is
fixed. This workaround should also avoid the other problem
detailed in <https://github.com/ksh93/ksh/issues/274>.
Resolves: https://github.com/ksh93/ksh/issues/274
Path-bound builtins on ksh (such as /opt/ast/bin/cat) break some
basic assumptions about paths in the shell that should hold true,
e.g., that a path output by whence -p or command -v should actually
point to an executable command. This commit should fix the
following:
1. Path-bound built-ins (such as /opt/ast/bin/cat) can now be
executed by invoking the canonical path (independently of the
value of $PATH), so the following will now work as expected:
$ /opt/ast/bin/cat --version
version cat (AT&T Research) 2012-05-31
$ (PATH=/opt/ast/bin:$PATH; "$(whence -p cat)" --version)
version cat (AT&T Research) 2012-05-31
In the event an external command by that path exists, the
path-bound builtin will now override it when invoked using the
canonical path. To invoke a possible external command at that
path, you can still use a non-canonical path, e.g.:
/opt//ast/bin/cat or /opt/ast/./bin/cat
2. Path-bound built-ins will now also be found on a PATH set
locally using an assignment preceding the command, so something
like the following will now work as expected:
$ PATH=/opt/ast/bin cat --version
version cat (AT&T Research) 2012-05-31
The builtin is not found by sh_exec() because the search for
builtins happens long before invocation-local preceding
assignments are processsed. This only happens in sh_ntfork(),
before forking, or in sh_fork(), after forking. Both sh_ntfork()
and sh_fork() call path_spawn() to do the actual path search, so
a check there will cover both cases.
This does mean the builtin will be run in the forked child if
sh_fork() is used (which is the case on interactive shells with
job.jobcontrol set, or always after compiling with SHOPT_SPAWN
disabled). Searching for it before forking would mean
fundamentally redesigning that function to be basically like
sh_ntfork(), so this is hard to avoid.
src/cmd/ksh93/sh/path.c: path_spawn():
- Before doing anything else, check if the passed path appears in
the builtins tree as a pathbound builtin. If so, run it. Since a
builtin will only be found if a preceding PATH assignment
temporarily changed the PATH, and that assignment is currently in
effect, we can just sh_run() the builtin so a nested sh_exec()
invocation will find and run it.
- If 'spawn' is not set (i.e. we must return), set errno to 0 and
return -2. See the change to sh_ntfork() below.
src/cmd/ksh93/sh/xec.c:
- sh_exec(): When searching for built-ins and the restricted option
isn't active, also search bltin_tree for names beginning with a
slash.
- sh_ntfork(): Only throw an error if the PID value returned is
exactly -1. This allows path_spawn() to return -2 after running a
built-in to tell sh_ntfork() to do the right things to restore
state.
src/cmd/ksh93/sh/parse.c: simple():
- When searching for built-ins at parse time, only exclude names
containing a slash if the restricted option is active. This
allows finding pointers to built-ins invoked by literal path like
/opt/ast/bin/cat, as long as that does not result from an
expansion. This is not actually necessary as sh_exec() will also
cover this case, but it is an optimisation.
src/lib/libcmd/getconf.c:
- Replace convoluted deferral to external command by a simple
invocation of the path to the native getconf command determined
at compile time (by src/lib/libast/comp/conf.sh). Based on:
https://github.com/ksh93/ksh/issues/138#issuecomment-816384871
If there is ever a system that has /opt/ast/bin/getconf as its
default native external 'getconf', then there would still be an
infinite recursion crash, but this seems extremely unlikely.
Resolves: https://github.com/ksh93/ksh/issues/138
Previous discussion: https://github.com/att/ast/issues/485
If ksh attempts to execute a non-executable command found in the
PATH, in some instances the error message and return status are
incorrect. In the example below, ksh returns with exit status 126
when using the -c execve(2) optimization or when using fork(2) in
an interactive shell. However, using posix_spawn(3) causes the exit
status to change:
$ echo 'print cannot execute' > /tmp/x
# Runs command with spawnveg (i.e., posix_spawn or vfork)
$ ksh -c 'PATH=/tmp; x; echo $?'
ksh: x: not found
127
# Runs command with execve
$ ksh -c 'PATH=/tmp; x'; echo $?
ksh: x: cannot execute [Permission denied]
126
# Runs command with fork
$ ksh -ic 'PATH=/tmp; x; echo $?'
ksh: x: cannot execute [Permission denied]
126
Since 'x' is in the PATH but can't be executed, the correct exit
status is 126, not 127. It's worth noting this bug doesn't cause
the regression tests to fail with ksh93u+m, but it does cause one
test to fail when run under dtksh:
path.sh[706]: Long nonexistent command name: got status 126, ''
This commit backports various fixes for this bug from ksh2020, with
additional fixes applied (since there were still some additional
issues the ksh2020 patch didn't fix). The lacking regression test
for exit status 126 in path.sh has been rewritten to test for more
scenarios where ksh failed to return the correct error message
and/or exit status. I can also confirm with this patch applied the
path.sh regression tests now pass when run under dtksh.
src/cmd/ksh93/sh/path.c:
- Add a comment to path_absolute() describing 'oldpp' is the
current pointer in the while loop and 'pp' is the next pointer.
Backported from:
https://github.com/att/ast/commit/a6cad450
- The patch from ksh2020 didn't fix this bug in the SHOPT_SPAWN
code (because ksh2020 prefers fork(2)), so issues with the exit
status could still occur when using spawnveg. To fix this, always
set 'noexec' to the value of errno if can_execute fails. Before
this fix, errno was discarded if 'pp' was a null pointer and
can_execute failed.
- If a command couldn't be executed and the error wasn't ENOENT,
save errno in a 'not_executable' variable. If an executable
command couldn't be found in the PATH, exit with status 126 and
set errno to the saved value. This was based on a ksh2020 bugfix,
but it has been reworked a little bit to fix a bug that caused a
mismatch between the error message shown and errno. Example with
a non-executable file in PATH:
$ nonexec
ksh2020: nonexec: cannot execute [No such file or directory]
The ksh2020 patch: <https://github.com/att/ast/pull/493>
- Backport a ksh2020 bugfix for directories in the PATH when
running one of the added regression tests on OpenBSD:
https://github.com/att/ast/pull/767
src/cmd/ksh93/data/msg.c,
src/cmd/ksh93/include/shell.h,
src/cmd/ksh93/sh/{path,xec}.c:
- If a command name is too long (ENAMETOOLONG), then it wasn't
found in the PATH. For that case return exit status 127, like
for ENOENT.
src/cmd/ksh93/tests/path.sh:
- Replace the old test with a new set of more extensive tests.
These tests check the error message and exit status when ksh
attempts to run a command using any of the following:
- execve(2), used with the last command run with -c (*A tests).
- posix_spawn(3)/vfork(2), used in noninteractive scripts (*B tests).
- fork(2), used in interactive shells with job control (*C tests).
- command -x (*D tests).
- exec(1) (*E tests).
- Add a regression test from ksh2020 for attempting to execute a
directory:
https://github.com/att/ast/pull/758
src/lib/libast/include/ast.h,
src/lib/libast/include/wait.h:
- Avoid bitshifts in macros for static error codes. The return
values of command not found and exec related errors are static
values and should not require any macro magic for calculation.
Backported from: https://github.com/att/ast/commit/c073b102
- Simplify EXIT_* and W* macros to use 8 bits.
This commit fixes a segmentation fault when an attempt was made to
unset the default KSH_VERSION variable prior any other nameref
activity such as creating another nameref or even reassigning the
nameref KSH_VERSION to something else.
(new shell without prior nameref activity)
$ nameref
KSH_VERSION=.sh.version
$ unset -n KSH_VERSION
Memory fault
src/cmd/ksh93/sh/name.c: _nv_unset():
- Add a 'Refdict' check before attempting to remove a value from it
as apparently one does not exist until some sort of nameref
activity occurs after shell startup as the default nameref of
'KSH_VERSION=.sh.version' does not create one.
The bugfix for BUG_CMDSPASGN backported in commit fae8862c caused
two regressions with the += operator:
1. The += operator did not append to variables. Reproducer:
$ integer foo=3
$ foo+=2 command eval 'echo $foo'
2
2. The += operator ignored the readonly attribute, modifying readonly
variables in the same manner as above. Reproducer
$ readonly bar=str
$ bar+=ing command eval 'echo $bar'
ing
Both of the regressions above were caused by nv_putval() failing to
clone the variable from the previous scope into the invocation-local
scope. As a result, 'foo+=2' was effectively 0 + 2 (since ksh didn't
clone 3). The first regression was noticed during the development of
ksh93v-, so to fix both bugs I've backported the bugfix for the
regression from the ksh93v- 2013-10-10 alpha version:
https://www.mail-archive.com/ast-users@lists.research.att.com/msg00369.html
src/cmd/ksh93/sh/name.c:
- To fix both of the bugs above, find the variable to modify with
nv_search(), then clone it into the invocation local scope. To
fix the readonly bug as well, this is done before the NV_RDONLY
check (otherwise np will be missing that attribute and be
incorrectly modified in the invocation-local scope).
- Update a nearby comment describing what sh_assignok() does (per this
comment: https://github.com/ksh93/ksh/pull/249#issuecomment-811381759)
src/cmd/ksh93/tests/builtins.sh:
- Add regression tests for both of the now fixed regressions,
loosely based on the regression tests in ksh93v-.
The recursion level for arithmetic expressions is kept track of in
a static 'level' variable in streval.c. It is reset when arithmetic
expressions throw an error.
But an error for an arithmetic expression may also occur elsewhere
-- at least in one case: when an arithmetic expression attempts to
change a read-only variable. In that case, the recursion level is
never reset because that code does not have access to the static
'level' variable.
If many such conditions occur (as in the new readonly.sh regression
tests), an arithmetic command like 'i++' may eventually fail with a
'recursion too deep' error.
To mitigate the problem, MAXLEVEL in streval.c was changed from 9
to 1024 in 264ba48b (as in the ksh 93v- beta). This commit leaves
that increase, but adds a proper fix.
src/cmd/ksh93/include/defs.h:
- Add global sh.arithrecursion (a.k.a. shp->arithrecursion)
variable to keep track of the arithmetic recursion level,
replacing the static 'level' variable in streval.c.
src/cmd/ksh93/sh/xec.c: sh_exec():
- Reset sh.arithrecursion before starting a new simple command
(TCOM), a new subshell with parentheses (TPAR), a new pipe
(TFIL), or a new [[ ... ]] command (TTST). These are the same
places where 'echeck' is set to 1 for --errexit and ERR trap
checks, so it should cover everything.
src/cmd/ksh93/sh/streval.c:
- Change all uses of 'level' to sh.arithrecursion.
- _seterror, aritherror(): No longer bother to reset the level
to zero here; xec.c should have this covered for all cases now.
src/cmd/ksh93/tests/arith.sh:
- Add tests for main shell and subshell.
src/cmd/ksh93/sh/args.c: sh_argopts():
- Remove special-casing for --posix (see also data/builtins.c) and
move the case -5: to the case ':' instead, so this option is
handled like all other long options. This change fixes two bugs:
1. 'set --posix' had no effect on the letoctal or braceexpand
options. Reproducer:
$ set --posix
$ [[ -o braceexpand ]]; echo $?
0
$ [[ -o letoctal ]]; echo $?
1
2. 'ksh --posix' could not run scripts correctly because it
wrongly enabled '-c'. Reproducer:
$ ksh --posix < <(echo 'exit 0')
ksh: -c requires argument
Usage: ksh [--posix] [arg ...]
Help: ksh [ --help | --man ] 2>&1
- Don't allow 'set --default' to unset the restricted option.
src/cmd/ksh93/tests/options.sh:
- Add regression tests for the bugs described above, using -o posix
and --posix.
src/cmd/ksh93/tests/restricted.sh:
- Add a regression test for 'set --default' in rksh.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
src/lib/libast/tm/tmlocale.c:
- Load the locale set by LC_TIME or LC_ALL if it hasn't been loaded
before or if it was loaded previously but isn't the current locale.
src/cmd/ksh93/tests/locale.sh:
- Add a regression test using the nl_NL.UTF-8 and ja_JP.UTF-8 locales.
Fixes: https://github.com/ksh93/ksh/issues/261
Many of these changes are minor typo fixes. The other changes
(which are mostly compiler warning fixes) are:
NEWS:
- The --globcasedetect shell option works on older Linux kernels
when used with FAT32/VFAT file systems, so remove the note about
it only working with 5.2+ kernels.
src/cmd/ksh93/COMPATIBILITY:
- Update the documentation on function scoping with an addition
from ksh93v- (this does apply to ksh93u+).
src/cmd/ksh93/edit/emacs.c:
- Check for '_AST_ksh_release', not 'AST_ksh_release'.
src/cmd/INIT/mamake.c,
src/cmd/INIT/ratz.c,
src/cmd/INIT/release.c,
src/cmd/builtin/pty.c:
- Add more uses of UNREACHABLE() and noreturn, this time for the
build system and pty.
src/cmd/builtin/pty.c,
src/cmd/builtin/array.c,
src/cmd/ksh93/sh/name.c,
src/cmd/ksh93/sh/nvtype.c,
src/cmd/ksh93/sh/suid_exec.c:
- Fix six -Wunused-variable warnings (the name.c nv_arrayptr()
fixes are also in ksh93v-).
- Remove the unused 'tableval' function to fix a -Wunused-function
warning.
src/cmd/ksh93/sh/lex.c:
- Remove unused 'SHOPT_DOS' code, which isn't enabled anywhere.
https://github.com/att/ast/issues/272#issuecomment-354363112
src/cmd/ksh93/bltins/misc.c,
src/cmd/ksh93/bltins/trap.c,
src/cmd/ksh93/bltins/typeset.c:
- Add dictionary generator function declarations for former
aliases that are now builtins (re: 1fbbeaa1, ef1621c1, 3ba4900e).
- For consistency with the rest of the codebase, use '(void)'
instead of '()' for print_cpu_times.
src/cmd/ksh93/sh/init.c,
src/lib/libast/path/pathshell.c:
- Move the otherwise unused EXE macro to pathshell() and only
search for 'sh.exe' on Windows.
src/cmd/ksh93/sh/xec.c,
src/lib/libast/include/ast.h:
- Add an empty definition for inline when compiling with C89.
This allows the timeval_to_double() function to be inlined.
src/cmd/ksh93/include/shlex.h:
- Remove the unused 'PIPESYM2' macro.
src/cmd/ksh93/tests/pty.sh:
- Add '# err_exit #' to count the regression test added in
commit 113a9392.
src/lib/libast/disc/sfdcdio.c:
- Move diordwr, dioread, diowrite and dioexcept behind
'#ifdef F_DIOINFO' to fix one -Wunused-variable warning and
multiple -Wunused-function warnings (sfdcdio() only uses these
functions when F_DIOINFO is defined).
src/lib/libast/string/fmtdev.c:
- Fix two -Wimplicit-function-declaration warnings on Linux by
including sys/sysmacros.h in fmtdev().
If a system administrator prefixes /opt/ast/bin to the path and
then invokes the shell in restricted mode, they clearly intend for
the user to run those AST utilities.
Similarly, if a system administrator sets a PATH for a restricted
shell that includes libraries listed in the .paths file, they must
have intended for the user to use those loadable built-ins, as they
will be associated with the pathnames of their respective
libraries. Since the user cannot change PATH or use the builtin
command, they still cannot load just any built-in they choose.
src/cmd/ksh93/sh/path.c:
- Remove SH_RESTRICTED check when handling path-bound builtins
or dynamic libaries containining builtins in $PATH.
src/cmd/ksh93/tests/builtins.sh:
- Add test verifying a restricted user can use /opt/ast/bin/cat
via a PATH search.
Progresses: https://github.com/ksh93/ksh/issues/138
This commit fixes BUG_CSUBSTDO, which could break stdout inside of
non-forking command substitutions. The breakage only occurred when
stdout was closed outside of the command substitution and a file
descriptor other than stdout was redirected in the command substitution
(such as stderr). Thanks to the ast-open-history repo, I was able to
identify and backport the bugfix from ksh93v- 2012-08-24.
This backport may fix other bugs as well. On 93v- 2012-08-24 it
fixed the regression below, though it was not triggered on 93u+(m).
src/cmd/ksh93/tests/heredoc.sh
487 print foo > $tmp/foofile
488 x=$( $SHELL 2> /dev/null 'read <<< $(<'"$tmp"'/foofile) 2> /dev/null;print -r "$REPLY"')
489 [[ $x == foo ]] || err_exit '<<< $(<file) not working'
src/cmd/ksh93/sh/io.c: sh_open():
- If the just-opened file descriptor exists in sftable and is
flagged with SF_STRING (as in non-forking command substitutions,
among other situations), then move the file descriptor to a
number >= 10.
src/cmd/ksh93/tests/io.sh:
- Add a regression test for BUG_CSUBSTDO, adapted from the one in
modernish.
The current version of 93u+m does not have proper support for the
LC_TIME variable. Setting LC_TIME has no effect on printf %T, and
if the locale is invalid no error message is shown:
$ LC_TIME=ja_JP.UTF-8
$ printf '%T\n' now
Wed Apr 7 15:18:13 PDT 2021
$ LC_TIME=invalid.locale
$ # No error message
src/cmd/ksh93/data/variables.c,
src/cmd/ksh93/include/variables.h,
src/cmd/ksh93/sh/init.c:
- Add support for the $LC_TIME variable. ksh93v- attempted to add
support for LC_TIME, but the patch from that version was extended
because the variable still didn't function correctly.
src/cmd/ksh93/tests/variables.sh:
- Add LC_TIME to the regression tests for LC_* variables.
These fixes are applied rather blindly as no one has yet managed to
understand the almost entirely uncommented arrays and variables
handling code (arrays.c, name.c, nvdisc.c, nvtree.c, nvtype.c).
Hopefully we'll figure all that out at some point. In the meantime
these backported fixes appear to work fine, and these bugs impact
the usability of 'enum', so I'm just going to have to violate my
own policy and backport these fixes without understanding them.
Thanks to @JohnoKing for putting in a lot of work tracing these.
Further discussion at: https://github.com/ksh93/ksh/issues/87
src/cmd/ksh93/sh/array.c:
- nv_arraysettype():
* Further simplify the function. After my initial simplification
of it (re: 5491fe97), I don't believe there's actually a need
to save a duplicate copy of the value. Use the pointer returned
by nv_getval() directly to restore the value.
* Cope with a null value (nv_getval() returning a NULL pointer).
This is needed for compatibility with the backported fix in
nvtype.c (below).
- array_putval(): If the array's value pointer (up->cp) is a
pointer to the empty string, it is set to NULL before calling
nv_putv() to prevent an empty string from being deleted. Backport
a fix from 93v- that restores the pointer to the empty string if
the NV_NOFREE attribute is set. Removing it somehow causes these
regressions:
enum.sh[86]: ${array[@]} doesn't yield all values for
associative enum arrays (expected 'green blue blue red
yellow green red orange'; got 'green blue blue yellow
green orange')
enum.sh[94]: unsetting associative enum array does not work
(got 'Color_t -A Colors=([foo]=red [rood]=red)')
enum.sh[116]: assigning first enum element to indexed array
failed (expected 'red red'; got 'BUG BUG')
- nv_associative(): Do not increase the 'nelem' (number of
elements) value of the array's 'header' struct if the array is
associative and of an enum type. The original 93v- fix only
checked for the NV_INTEGER attribute, but backporting that caused
several regressions. Using a debug output command I've determined
that the exact value of 'type' is somehow consistently set to
0x26 if the array is associative and of an enum type, which is
NV_INTEGER | NV_LTOU | NV_RJUST as defined in include/nval.h. I
cannot find where/how that value is determined. In any case this
fix, based on but more specific than the 93v- one, appears to
work fine. Removing it somehow causes this regression:
enum.sh[94]: unsetting associative enum array does not work
(got 'Color_t -A Colors=()')
src/cmd/ksh93/sh/nvtype.c: nv_settype():
- Another fix backported from 93v-. If the variable is an array,
also set the type of element 0 of that array using a call to
nv_arraysettype(). The value may be null. Removing this somehow
causes this regression:
enum.sh[94]: unsetting associative enum array does not work
(got 'Color_t -A Colors=()')
src/cmd/ksh93/tests/enum.sh:
- Add tests for all the bugs fixed here, plus some hypothetical
bugs (e.g., do the same tests for indexed enum type arrays as for
associative enum type arrays, even though indexed enum type
arrays didn't have all the same problems).
Co-authored-by: Johnothan King <johnothanking@protonmail.com>
Resolves: https://github.com/ksh93/ksh/issues/87
Simple reproducer:
set -A arr a b c d; : ${arr[1..2]}; unset arr[1]; echo ${arr[@]}
Output:
a
Expected output:
a c d
The ${arr[1..2]} expansion broke the subsequent 'unset' command
so that it unsets element 1 and on, instead of only 1.
This regression was introduced in nv_endsubscript() on 2009-07-31:
https://github.com/ksh93/ast-open-history/commit/c47896b4/src/cmd/ksh93/sh/array.c
That change checks for the ARRAY_SCAN attribute which enables
processing ranges of array elements instead of single array
elements, and restores it after. That restore is evidently not
correct as it causes the subsequent unset command to malfunction.
If we revert that change, the bug disappears and the regression
tests show no failures. However, I don't know what this was meant
to accomplish and what other bug we might introduce by reverting
this. However, no corresponding regression test was added along
with the 2009-07-31 change, nor is there any corresponding message
in the changelog. So this looks to be one of those mystery changes
that we'll never know the reason for.
Since we currently have proof that this change causes breakage and
no evidence that it fixes anything, I'll go ahead and revert it
(and add a regression test, of course). If that causes another
regression, hopefully someone will find it at some point.
src/cmd/ksh93/sh/array.c: nv_endsubscript():
- Revert the 2009-07-31 change that saves/restores the ARRAY_SCAN
attribute.
- Keep the 'ap' pointer as it is now used by newer code. Move the
declaration up to the beginning of the block, as is customary.
src/cmd/ksh93/sh/init.c:
- Cosmetic change: remove an unused array_scan() macro that I found
when grepping the code for ARRAY_SCAN. The macro was introduced
in version 2001-06-01 but the code that used it was replaced in
version 2001-07-04, without removing the macro itself.
Resolves: https://github.com/ksh93/ksh/issues/254
To set a window title in bash and zsh, the $PS1 prompt can be set
with the title placed between $'\E]0;' and $'\a':
set -o emacs # Or vi mode
typeset -A fmt=(
[start_title]=$'\E]0;'
[end_title]=$'\a'
)
PS1="${fmt[start_title]}$(hostname): $(uname)${fmt[end_title]}\$ "
This also works in ksh unless the shell receives SIGWINCH. With a
$PS1 that sets a window title, the prompt breaks until two
interrupts are received. This is caused by ed_setup() skipping
$'\a' (the bell character) when setting up the e_prompt buffer
which is an edited version of the final line of the PS1 prompt for
use when redrawing the command line.
One fix would be to avoid cutting out the bell character. But if
the prompt contains a bell, we only want the terminal to beep when
a new prompt is printed, and not upon refreshing the command line,
e.g. when receiving SIGWINCH or pressing Ctrl+L.
To avoid the problem, this commit adds code that cuts out sequences
of the form ESC ] <number> ; <text> BELL from the prompt redraw
buffer altogether. They are not needed there because these
sequences will already have taken effect when the full prompt was
printed by io_prompt().
This commit also adds a tweak that should improve the recognition
of other escape sequences to count their length.
src/cmd/ksh93/edit/edit.c: ed_setup():
- When preparing the e_prompt buffer, cut out dtterm/xterm
Operating System Commands that set window/icon title, etc.
See: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
- When counting the length of escape sequences in that part of PS1,
try to recognize some more types of sequences. These changes are
part of a ksh2020 patch: https://github.com/att/ast/issues/399
src/cmd/ksh93/sh.1:
- Document that any '!' in escape sequences in the PS1 prompt needs
to be changed to '!!'. To avoid breaking compatibility, this
requirement is documented instead of backporting the changes to
io_prompt() from https://github.com/att/ast/issues/399 which try
to remove that requirement for specific escape sequences.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
Ksh currently restricts readonly scalar variables from having their
values directly changed via a value assignment. However, since ksh
allows variable attributes to be altered, the variable's value can
be indirectly altered. For instance, if TMOUT=900 (for a 15 minute
idle timeout) was set to readonly, all that is needed to alter the
value of TMOUT from 900 to 0 is to issue 'typeset -R1 TMOUT',
perhaps followed by a 'typeset -i TMOUT' to turn off the shell's
timeout value.
In addition, there are problems with arrays. The following is
incorrectly allowed:
typeset -a arr=((a b c) 1)
readonly arr
arr[0][1]=d
arr=(alphas=(a b c);name=x)
readonly arr.alphas
arr.alphas[1]=([b]=5)
arr=(alphas=(a b c);name=x)
readonly arr.alphas
arr.alphas[1]=(b)
typeset -C arr=(typeset -r -a alphas=(a b c);name=x)
arr.alphas[1]=()
src/cmd/ksh93/bltins/typeset.c: setall():
- Relocate readonly attribute check higher up the code and widen
its application to issue an error message if the pre-existing
name-pair has the readonly bit flag set.
- To avoid compatibility problems, don't check for readonly if
NV_RDONLY is the only attribute set (ignoring NV_NOFREE). This
allows 'readonly foo; readonly foo' to keep working.
src/cmd/ksh93/sh/array.c: nv_endsubscript():
- Apply a readonly flag check when an array subscript or append
assignment occurs, but allow type variables (typeset -T) as they
utilize '-r' for 'required' sub-variables.
src/cmd/ksh93/tests/readonly.sh:
- New file. Create readonly tests that validate the warning message
and validate that the readonly variable did not change.
src/cmd/ksh93/sh/streval.c:
- Bump MAXLEVEL from 9 to 1024 as a workaround for arithmetic
expansion, avoiding a spurious error about too much recursion
when the readonly.sh tests are run. This change is backported
from ksh 93v-.
TODO: debug a spurious increase in arithmetic recursion level
variable when readonly.sh tests with 'typeset -i' are run.
That is a different bug for a different commit.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
This commit fixes a bug in the ksh uname builtin's -d option that could
change the output of -o (I was only able to reproduce this on Linux):
$ builtin uname
$ uname -o
GNU/Linux
$ uname -d
(none)
$ uname -o
(none)
I identified this patch from ksh2020 as a fix for this bug:
<https://github.com/att/ast/pull/1187>
The linked patch was meant to fix a crash in 'uname -d', although I've
had no luck reproducing it: <https://github.com/att/ast/issues/1184>
src/lib/libcmd/uname.c:
- Pass correct buffer to getdomainname() while executing uname -d.
src/cmd/ksh93/tests/builtins.sh:
- Add a regression test for the reported 'uname -d' crash.
- Add a regression test for the output of 'uname -o' after 'uname -d'.
- To handle potential crashes when running the regression tests in older
versions of ksh, fork the command substitutions that run 'uname -d'.
This bug was first reported at <https://github.com/att/ast/issues/8>.
The 'cd' command currently takes the value of $OLDPWD from the
wrong scope. In the following example 'cd -' will change the
directory to /bin instead of /tmp:
$ OLDPWD=/bin ksh93 -c 'OLDPWD=/tmp cd -'
/bin
src/cmd/ksh93/bltins/cd_pwd.c:
- Use sh_scoped() to obtain the correct value of $OLDPWD.
- Fix a use-after-free bug. Make the 'oldpwd' variable a static
char that points to freeable memory. Each time cd is used, this
variable is freed if it points to a freeable memory address and
isn't also a pointer to shp->pwd.
src/cmd/ksh93/sh/path.c: path_pwd():
- Simplify and add comments.
- Scope $PWD properly.
src/cmd/ksh93/tests/builtins.sh,
src/cmd/ksh93/tests/leaks.sh:
- Backport the ksh2020 regression tests for 'cd -' when $OLDPWD is
set.
- Add test for $OLDPWD and $PWD after subshare.
- Add test for $PWD after 'cd'.
- Add test for possible memory leak.
- Add testing for 'unset' on OLDPWD and PWD.
src/cmd/ksh93/COMPATIBILITY:
- Add compatibility note about changes to $PWD and $OLDPWD.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
This bug was originally reported at <https://github.com/att/ast/issues/1467>.
A crash can occur when using the 'b' or 'B' vi mode commands to go back
one word. I was able to reproduce these crashes with 100% consistency on
an OpenBSD virtual machine when ksh is compiled with -D_std_malloc.
Reproducer:
$ set -o vi
$ asdf <ESC> <b or B>
The fix is based on Matthew DeVore's analysis:
> I suspect this is caused by this line:
>> while (vi_isalph(tcur_virt) && tcur_virt >= first_virt) --tcur_virt;
> which is in the b codepath. It checks vi_isalph(tcur_virt) before checking
> if tcur_virt is in range. These two clauses should be reversed. Note that
> line 316 is a similar check for pressing B, and there the tcur_virt value
> is checked first.
src/cmd/ksh93/edit/vi.c:
- Check tcur_virt before using isalph() or isblank() to fix both crashes.
At the start of the backword() while loop this check was performed
twice, so the redundant check has been removed.
src/cmd/ksh93/tests/pty.sh:
- Add a regression test for the b, B, w and W editor commands.
When test is passed the '=~' operator, it will silently fail with
exit status 1:
$ test foo =~ foo; echo $?
1
This bug is caused by test_binop reaching the 'NOTREACHED' area of
code. The bugfix was adapted from ksh2020:
https://github.com/att/ast/issues/1152
src/cmd/ksh93/bltins/test.c: test_binop():
- Error out with a message suggesting usage of '[[ ... ]]' if '=~'
is passed to the test builtin.
- Special-case TEST_END (']]') as that is not really an operator.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
One of the best-kept secrets of libast/ksh93 is that the code
includes support for case-insensitive file name generation (a.k.a.
pathname expansion, a.k.a. globbing) as well as case-insensitive
file name completion on interactive shells, depending on whether
the file system is case-insensitive or not. This is transparently
determined for each directory, so a path pattern that spans
multiple file systems can be part case-sensitive and part case-
insensitive. In more precise terms, each slash-separated path name
component pattern P is treated as ~(i:P) if its parent directory
exists on a case-insensitive file system. I recently discovered
this while dealing with <https://github.com/ksh93/ksh/issues/223>.
However, that support is dead code on almost all current systems.
It depends on pathconf(2) having a _PC_PATH_ATTRIBUTES selector.
The 'c' attribute is supposedly returned if the given directory is
on a case insensitive file system. There are other attributes as
well (at least 'l', see src/lib/libcmd/rm.c). However, I have been
unable to find any system, current or otherwise, that has
_PC_PATH_ATTRIBUTES. Google and mailing list searches yield no
relevant results at all. If anyone knows of such a system, please
add a comment to this commit on GitHub, or email me.
An exception is Cygwin/Windows, on which the "c" attribute was
simply hardcoded, so globbing/completion is always case-
insensitive. As of Windows 10, that is wrong, as it added the
possibility to mount case-sensitive file systems.
On the other hand, this was never activated on the Mac, even
though macOS has always used a case-insensitive file like Windows.
But, being UNIX, it can also mount case-sensitive file systems.
Finally, Linux added the possibility to create individual case-
insensitive ext4 directories fairly recently, in version 5.2.
https://www.collabora.com/news-and-blog/blog/2020/08/27/using-the-linux-kernel-case-insensitive-feature-in-ext4/
So, since this functionality latently exists in the code base, and
three popular OSs now have relevant file system support, we might
as well make it usable on those systems. It's a nice idea, as it
intuitively makes sense for globbing and completion behaviour to
auto-adapt to file system case insensitivity on a per-directory
basis. No other shell does this, so it's a nice selling point, too.
However, the way it is coded, this is activated unconditionally on
supported systems. That is not a good idea. It will surprise users.
Since globbing is used with commands like 'rm', we do not want
surprises. So this commit makes it conditional upon a new shell
option called 'globcasedetect'. This option is only compiled into
ksh on systems where we can actually detect FS case insensitivity.
To implement this, libast needs some public API additions first.
*** libast changes ***
src/lib/libast/features/lib:
- Add probes for the linux/fs.h and sys/ioctl.h headers.
Linux needs these to use ioctl(2) in pathicase(3) (see below).
src/lib/libast/path/pathicase.c,
src/lib/libast/include/ast.h,
src/lib/libast/man/path.3,
src/lib/libast/Mamfile:
- Add new pathicase(3) public API function. This uses whatever
OS-specific method it can detect at compile time to determine if
a particular path is on a case-insensitive file system. If no
method is available, it only sets errno to ENOSYS and returns -1.
Currently known to work on: macOS, Cygwin, Linux 5.2+, QNX 7.0+.
- On systems (if any) that have the mysterious _PC_PATH_ATTRIBUTES
selector for pathconf(2), call astconf(3) and check for the 'c'
attribute to determine case insensitivity. This should preserve
compatibility with any such system.
src/lib/libast/port/astconf.c:
- dynamic[]: As case-insensitive globbing is now optional on all
systems, do not set the 'c' attribute by default on _WINIX
(Cygwin/Windows) systems.
- format(): On systems that do not have _PC_PATH_ATTRIBUTES, call
pathicase(3) to determine the value for the "c" (case
insensitive) attribute only. This is for compatibility as it is
more efficient to call pathicase(3) directly.
src/lib/libast/misc/glob.c,
src/lib/libast/include/glob.h:
- Add new GLOB_DCASE public API flag to glob(3). This is like
GLOB_ICASE (case-insensitive matching) except it only makes the
match case-insensitive if the file system for the current
pathname component is determined to be case-insensitive.
- gl_attr(): For efficiency, call pathicase(3) directly instead of
via astconf(3).
- glob_dir(): Only call gl_attr() to determine file system case
insensitivity if the GLOB_DCASE flag was passed. This makes case
insensitive globbing optional on all systems.
- glob(): The options bitmask needs to be widened to fit the new
GLOB_DCASE option. Define this centrally in a new GLOB_FLAGMASK
macro so it is easy to change it along with GLOB_MAGIC (which
uses the remaining bits for a sanity check bit pattern).
src/lib/libast/path/pathexists.c:
- For efficiency, call pathicase(3) directly instead of via
astconf(3).
*** ksh changes ***
src/cmd/ksh93/features/options,
src/cmd/ksh93/SHOPT.sh:
- Add new SHOPT_GLOBCASEDET compile-time option. Set it to probe
(empty) by default so that the shell option is compiled in on
supported systems only, which is determined by new iffe feature
test that checks if pathicase(3) returns an ENOSYS error.
src/cmd/ksh93/data/options.c,
src/cmd/ksh93/include/shell.h:
- Add -o globcasedetect shell option if compiling with
SHOPT_GLOBCASEDET.
src/cmd/ksh93/sh/expand.c: path_expand():
- Pass the new GLOB_DCASE flag to glob(3) if the
globcasedetect/SH_GLOBCASEDET shell option is set.
src/cmd/ksh93/edit/completion.c:
- While file listing/completion is based on globbing and
automatically becomes case-insensitive when globbing does, it
needs some additional handling to make a string comparison
case-insensitive in corresponding cases. Otherwise, partial
completions may be deleted from the command line upon pressing
tab. This code was already in ksh 93u+ and just needs to be
made conditional upon SHOPT_GLOBCASEDET and globcasedetect.
- For efficiency, call pathicase(3) directly instead of via
astconf(3).
src/cmd/ksh93/sh.1:
- Document the new globcasedetect shell option.
These are minor fixes I've accumulated over time. The following
changes are somewhat notable:
- Added a missing entry for 'typeset -s' to the man page.
- Add strftime(3) to the 'see also' section. This and the date(1)
addition are meant to add onto the documentation for 'printf %T'.
- Removed the man page the entry for ksh reading $PWD/.profile on
login. That feature was removed in commit aa7713c2.
- Added date(1) to the 'see also' section of the man page.
- Note that the 'hash' command can be used instead of 'alias -t' to
workaround one of the caveats listed in the man page.
- Use an 'out of memory' error message rather than 'out of space'
when memory allocation fails.
- Replaced backticks with quotes in some places for consistency.
- Added missing documentation for the %P date format.
- Added missing documentation for the printf %Q and %p formats
(backported from ksh2020: https://github.com/att/ast/pull/1032).
- The comments that show each builtin's options have been updated.
Upon encountering two filenames with multibyte characters starting
with the same byte, a partial multibyte character was completed.
Reproducer (to run in UTF-8 locale):
$ touch XXXá XXXë
$ : XX <== pres tab
$ : XXX^? <== partial multibyte character appears
Note: á is $'\xc3\xa1' and ë is $'\xc3\xab' (same initial byte).
src/cmd/ksh93/edit/completion.c:
- Add multibyte support to the charcmp() and overlaid() functions.
Thanks to Harald van Dijk for useful code and suggestions.
- Add a few missing mbinit() calls. The state of multibyte
processing must be reset before starting a new loop in case a
previous processing run was interrupted mid-character.
src/cmd/ksh93/tests/pty.sh:
- Add test based on Harald's reproducer.
Resolves: https://github.com/ksh93/ksh/issues/223
Until now, when performing any tilde expansion like ~/foo or
~user/foo, ksh added a placeholder built-in command called
'.sh.tilde', ostensibly with the intention to allow users to
override it with a shell function or custom builtin. The multishell
ksh93 repo <https://github.com/multishell/ksh93/> shows this was
added sometime between 2002-06-28 and 2004-02-29. However, it has
never worked and crashed the shell.
This commit replaces that with something that works. Specific tilde
expansions can now be overridden using .set or .get discipline
functions associated with the .sh.tilde variable (see manual,
Discipline Functions).
For example, you can use either of:
.sh.tilde.set()
{
case ${.sh.value} in
'~tmp') .sh.value=${XDG_RUNTIME_DIR:-${TMPDIR:-/tmp}} ;;
'~doc') .sh.value=~/Documents ;;
'~ksh') .sh.value=/usr/local/src/ksh93/ksh ;;
esac
}
.sh.tilde.get()
{
case ${.sh.tilde} in
'~tmp') .sh.value=${XDG_RUNTIME_DIR:-${TMPDIR:-/tmp}} ;;
'~doc') .sh.value=~/Documents ;;
'~ksh') .sh.value=/usr/local/src/ksh93/ksh ;;
esac
}
src/cmd/ksh93/include/variables.h,
src/cmd/ksh93/data/variables.c:
- Add SH_TILDENOD for a new ${.sh.tilde} predefined variable.
It is initially unset.
src/cmd/ksh93/sh/macro.c:
- sh_btilde(): Removed.
- tilde_expand2(): Rewritten. I started out with the tiny version
of this function from the 2002-06-28 version of ksh. It uses the
stack instead of sfio, which is more efficient. A bugfix for
$HOME == '/' was retrofitted so that ~/foo does not become
//foo instead of /foo. The rest is entirely new code.
To implement the override functionality, it now checks if
${.sh.tilde} has any discipline function associated with it.
If it does, it assigns the tilde expression to ${.sh.tilde} using
nv_putval(), triggering the .set discipline, and then reads it
back using nv_getval(), triggering the .get discipline. The
resulting value is used if it is nonempty and does not still
start with a tilde.
src/cmd/ksh93/bltins/typeset.c,
src/cmd/ksh93/tests/builtins.sh:
- Since ksh no longer adds a dummy '.sh.tilde' builtin, remove the
ad-hoc hack that suppressed it from the output of 'builtin'.
src/cmd/ksh93/tests/tilde.sh:
- Add tests verifying everything I can think of, as well as tests
for bugs found and fixed during this rewrite.
src/cmd/ksh93/tests/pty.sh:
- Add test verifying that the .sh.tilde.set() discipline does not
modify the exit status value ($?) when performing tilde expansion
as part of tab completion.
src/cmd/ksh93/sh.1:
- Instead of "tilde substitution", call the basic mechanism "tilde
expansion", which is the term used everywhere else (including the
1995 Bolsky/Korn ksh book).
- Document the new override feature.
Resolves: https://github.com/ksh93/ksh/issues/217
A discipline function could incorrectly influence the value of $?
(exit status of last command) outside its context if it was
triggered without another command being run, e.g. when a prompt
variable is read, or COLUMNS or LINES is set.
Reproducers include:
PS1 prompt:
$ PS1.get() { true; }
$ false
$ echo $?
0
PS2 prompt:
$ PS2.get() { return 13; }
$ \
>
$ echo $?
13
The set discipline is affected too, e.g. COLUMNS and LINES:
$ COLUMNS.set() { return 13; }
$ true
$ (press return)
$ echo $?
13
There are probably other contexts where the shell reads or changes
variables without running commands, allowing their get or set
disciplines to influence $?. So this commit makes ksh save $? for
all .get, .set, .append, and .unset discipline calls.
src/cmd/ksh93/sh/nvdisc.c:
- assign(): Save/restore $? when running a .set/.append/.unset
discipline function.
- lookup(): Save/restore $? when running a .get discipline.
src/cmd/ksh93/tests/pty.sh:
- Add a regression test for $? after displaying a prompt
and when setting a LINES.set discipline function.
src/cmd/ksh93/tests/return.sh:
- The above test fails in script form on ksh93u+ and ksh2020, as
it exposes another form of #117 that occurs after running a
subshell. Add the above regression test here as well
(re: 092b90da).
Co-authored-by: Martijn Dekker <martijn@inlv.org>
For most numeric types the last provided one wins out. This commit
closes the gap for -F and -i numerics to not be covered up by other
preceding float types. Note: -u for requesting an unsigned float or
integer was considered and decided to be left alone as it stands,
so as to not allow the variable to become an uppercased string if
the requested options ended with a -u. As it stands for a case when
multiple numeric types are requested, a -u option may be applied
after the last numeric type is processed.
Examples:
-EF becomes -F
-Fi becomes -i
-Fu becomes -F
-uF becomes -F
-Fui becomes -i (because isfloat==1, unsigned is not applied)
-Fiu becomes -iu (isfloat is reset and allows unsigned to be set)
src/cmd/ksh93/bltins/typeset.c: b_typeset():
- Reset attribute bit flags for -E and -X when -F is requested by
adding in NV_EXPNOTE to be removed.
- For -i option if a float precedes it, reset isfloat and -E/-F
attribute bit flags.
- Take into account the impact of the shortint flag on floats.
src/cmd/ksh93/tests/attributes.sh:
- Add some validation tests to confirm that, when a -F follows
either -E or -X, -F is used.
- Add some validation tests to confirm that, when -F/E/X precede
a -i, the variable becomes an integer and not a float.
- Add in various tests when -s followed a float.
There was an issue with tilde expansion if the HOME var is unset.
$ unset HOME
$ echo ~
martijn
Only the username is returned. Users are more likely to expect the
current user's home directory as configured in the OS.
POSIXly, the expansion of ~ is based on the value of HOME. If HOME
is unset, the results are unspecified. After unsetting HOME, in
bash, ~ returns the user's home directory as specified by the OS,
whereas in all other shells, ~ expands to the empty string. Only
ksh93 returns the username. The behaviour of bash is more useful.
Discussion:
https://github.com/ksh93/ksh/pull/225#issuecomment-799074107
src/cmd/ksh93/sh/macro.c,
src/cmd/ksh93/tests/tilde.sh:
- sh_tilde(): Backport fix by Mike Gilbert from ksh2020.
See: https://github.com/att/ast/issues/1391https://github.com/att/ast/pull/1396https://github.com/att/ast/commit/070d365d
- Add test.
src/cmd/ksh93/COMPATIBILITY:
- Note this change.
This commit fixes a long-standing bug (present since at least
ksh93r) that caused a file descriptor leak when passing a process
substitution to a function, or (if compiled with SHOPT_SPAWN) to a
nonexistent command.
The leaks only occurred when ksh was compiled with SHOPT_DEVFD; the
FIFO method was unaffected.
src/cmd/ksh93/sh/xec.c: sh_exec():
- When a process substitution is passed to a built-in, the
remaining file descriptor is closed with sh_iorestore. Do the
same thing when passing a process substitution to a function.
This is done by delaying the sh_iorestore() call to 'setexit:'
where both built-ins and functions terminate and set the exit
status ($?).
This means that call now will not be executed if a longjmp is
done, e.g. due to an error in a special built-in. However, there
is already another sh_iorestore() call in main.c, exfile(), line
418, that handles that scenario.
- sh_ntfork() can fail, so rather than assume it will succeed,
handle a failure by closing extra file descriptors with
sh_iorestore(). This fixes the leak on command not found with
SHOPT_SPAWN.
src/cmd/ksh93/include/defs.h:
- Since the file descriptor leaks are now fixed, remove the
workaround that forced ksh to use the FIFO method.
src/cmd/ksh93/SHOPT.sh:
- Add SHOPT_DEVFD as a configurable option (default: probe).
src/cmd/ksh93/tests/io.sh:
- Add a regression test for the 'not found' file descriptor leak.
- Add a test to ensure it keeps working with 'command'.
Fixes: https://github.com/ksh93/ksh/issues/67
On systems where ksh needs to use the older and less secure FIFO
method for process substitutions (which is currently all of them as
the more modern and solid /dev/fd method is still broken, see #67),
process substitutions could leave background processes hanging in
these two scenarios:
1. If the parent process exits without opening a pipe to the child
process forked by the process substitution. The fifo_check()
function in xec.c, which is periodically called to check if the
parent process still exists while waiting for it to open the
FIFO, verified the parent process's existence by checking if the
PPID had reverted to 1, the traditional PID of init. However,
POSIX specifies that the PPID can revert to any implementation-
defined system process in that case. So this breaks on certain
systems, causing unused process substitutions to hang around
forever as they never detect that the parent disappeared.
The fix is to save the current PID before forking and having the
child check if the PPID has changed from that saved PID.
2. If command invoked from the main shell is passed a process
substitution, but terminates without opening the pipe to the
process substitution. In that case, the parent process never
disappears in the first place, because the parent process is the
main shell. So the same infinite wait occurs in unused process
substitutions, even after correcting problem 1.
The fix is to remember all FIFOs created for any number of
process substitutions passed to a single command, and unlink any
remaining FIFOs as they represent unused command substitutions.
Unlinking them FIFOs causes sh_open() in the child to fail with
ENOENT on the next periodic check, which can easily be handled.
Fixing these problems causes the FIFO method to act identically to
the /dev/fd method, which is good for compatibility. Even when #67
is fixed this will still be important, as ksh also runs on systems
that do not have /dev/fd (such as AIX, HP-UX, and QNX), so will
fall back to using FIFOs.
--- Fix problem 1 ---
src/cmd/ksh93/sh/xec.c:
- Add new static fifo_save_ppid variable.
- sh_exec(): If a FIFO is defined, save the current PID in
fifo_save_ppid for the forked child to use.
- fifo_check(): Compare PPID against the saved value instead of 1.
--- Fix problem 2 ---
To keep things simple I'm abusing the name-value pair routines used
for variables for this purpose. The overhead is negligible. A more
elegant solution is possible but would involve adding more code.
src/cmd/ksh93/include/defs.h: _SH_PRIVATE:
- Define new sh.fifo_tree pointer to a new FIFO cleanup tree.
src/cmd/ksh93/sh/args.c: sh_argprocsubs():
- After launching a process substitution in the background,
add the FIFO to the cleanup list before freeing it.
src/cmd/ksh93/sh/xec.c:
- Add fifo_cleanup() that unlinks all FIFOs in the cleanup list and
clears/closes the list. They should only still exist if the
command never used them, however, just run 'unlink' and don't
check for existence first as that would only add overhead.
- sh_exec():
* Call fifo_cleanup() on finishing all simple commands (when
setting $?) or when a special builtin fails.
* When forking, clear/close the cleanup list; we do not want
children doing duplicate cleanup, particularly as this can
interfere when using multiple process substitutions in one
command.
* Process substitution handling:
> Change FIFO check frequency from 500ms to 50ms.
Note that each check sends a signal that interrupts open(2),
causing sh_open() to reinvoke it. This causes sh_open() to
fail with ENOENT on the next check when the FIFO no longer
exists, so we do not need to add an additional check for
existence to fifo_check(). Unused process substitutions now
linger for a maximum of 50ms.
> Do not issue an error message if errno == ENOENT.
- sh_funct(): Process substitutions can be passed to functions as
well, and we do not want commands within the function to clean up
the FIFOs for the process substitutions passed to it from the
outside. The problem is solved by simply saving fifo_tree in a
local variable, setting it to null before running the function,
and cleaning it up before restoring the parent one at the end.
Since sh_funct() is called recursively for multiple-level
function calls, this correctly gives each function a locally
scoped fifo_tree.
--- Tests ---
src/cmd/ksh93/tests/io.sh:
- Add tests covering the failing scenarios.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
This commit fixes two interrelated problems.
1. The -v unary test/[/[[ operator is documented to test if a
variable is set. However, it always returns true for variable
names with a numeric attribute, even if the variable has not
been given a value. Reproducer:
$ ksh -o nounset -c 'typeset -i n; [[ -v n ]] && echo $n'
ksh: n: parameter not set
That is clearly wrong; 'echo $n' should never be reached and the
error should not occur, and does not occur on mksh or bash.
2. Fixing the previous problem revealed serious breakage in short
integer type variables that was being masked. After applying
that fix and then executing 'typeset -si var=0':
- The conditional assignment expansions ${var=123} and
${var:=123} assigned 123 to var, even though it was set to 0.
- The expansions ${var+s} and ${var:+n} incorrectly acted as if
the variable was unset and empty, respectively.
- '[[ -v var ]]' and 'test -v var' incorrectly returned false.
The problems were caused by a different storage method for short
ints. Their values were stored directly in the 'union Value'
member of the Namval_t struct, instead of allocated on the stack
and referred to by a pointer, as regular integers and all other
types do. This inherently broke nv_isnull() as this leaves no
way to distinguish between a zero value and no value at all.
(I'm also pretty sure it's undefined behaviour in C to check for
a null pointer at the address where a short int is stored.)
The fix is to store short ints like other variables and refer
to them by pointers. The NV_INT16P combined bit mask already
existed for this, but nv_putval() did not yet support it.
src/cmd/ksh93/bltins/test.c: test_unop():
- Fix problem 1. For -v, only check nv_isnull() and do not check
for the NV_INTEGER attribute (which, by the way, is also used
for float variables by combining it with other bits).
See also 5aba0c72 where we recently fixed nv_isnull() to
work properly for all variable types including short ints.
src/cmd/ksh93/sh/name.c: nv_putval():
- Fix problem 2, part 1. Add support for NV_INT16P. The code is
simply copied and adapted from the code for regular integers, a
few lines further on. The regular NV_SHORT code is kept as this
is still used for some special variables like ${.sh.level}.
src/cmd/ksh93/bltins/typeset.c: b_typeset():
- Fix problem 2, part 2. Use NV_INT16P instead of NV_SHORT.
src/cmd/ksh93/tests/attributes.sh:
- Add set/unset/empty/nonempty tests for all numeric types.
src/cmd/ksh93/tests/bracket.sh,
src/cmd/ksh93/tests/comvar.sh:
- Update a couple of existing tests.
- Add test for [[ -v var ]] and [[ -n ${var+s} ]] on unset
and empty variables with many attributes.
src/cmd/ksh93/COMPATIBILITY:
- Add a note detailing the change to test -v.
src/cmd/ksh93/data/builtins.c,
src/cmd/ksh93/sh.1:
- Correct 'typeset -C' documentation. Variables declared as
compound are *not* initially unset, but initially have the empty
compound value. 'typeset' outputs them as:
typeset -C foo=()
and not:
typeset -C foo
and nv_isnull() is never true for them. This may or may not
technically be a bug. I don't think it's worth changing, but
it should at least be documented correctly.
These expansions are supposed to yield all variable names beginning
with the indicated prefix. This should include the variable name
that is identical to the prefix (as 'prefix' begins with 'prefix').
This bugfix is backported from the abandoned ksh 93v- beta, so AT&T
intended this change. It also makes ksh work like bash in this.
src/cmd/ksh93/sh/macro.c: varsub(): M_NAMESCAN:
- Check if the prefix itself exists. If so, start with that.
src/cmd/ksh93/tests/variables.sh:
- Add tests for these expansions.
src/cmd/ksh93/sh.1:
- Fix the incomplete documentation of these expansions.
src/cmd/ksh93/COMPATIBILITY:
- Note the change as it's potentially incompatible in corner cases.
Resolves: https://github.com/ksh93/ksh/issues/183
This commit fixes at least three bugs:
1. When issuing 'typeset -p' for unset variables typeset as short
integer, a value of 0 was incorrectly diplayed.
2. ${x=y} and ${x:=y} were still broken for short integer types
(re: 9f2389ed). ${x+set} and ${x:+nonempty} were also broken.
3. A memory fault could occur if typeset -l followed a -s option
with integers. Additonally, now the last -s/-l wins out as the
option to utilize instead of it always being short.
src/cmd/ksh93/include/name.h:
- Fix the nv_isnull() macro by removing the direct exclusion of
short integers from this set/unset test. This breaks few things
(only ${.sh.subshell} and ${.sh.level}, as far as we can tell)
while potentially correcting many aspects of short integer use
(at least bugs 1 and 2 above), as this macro is widely used.
- union Value: add new pid_t *pidp pointer member for PID values
(see further below).
src/cmd/ksh93/bltins/typeset.c: b_typeset():
- To fix bug 3 above, unset the 'shortint' flag and NV_SHORT
attribute bit upon encountering the -l optiobn.
*** To fix ${.sh.subshell} to work with the new nv_isnull():
src/cmd/ksh93/sh/defs.h:
- Add new 'realsubshell' member to the shgd (aka shp->gd) struct
which will be the integer value for ${.sh.subshell}.
src/cmd/ksh93/sh/init.c,
src/cmd/ksh93/data/variables.c:
- Initialize SH_SUBSHELLNOD as a pointer to shgd->realsubshell
instead of using a short value (.s) directly. Using a pointer
allows nv_isnull() to return a positive for ${.sh.subshell} as
a non-null pointer is what it checks for.
- While we're at it, initialize PPIDNOD ($PPID) and SH_PIDNOD
(${.sh.pid}) using the new pdip union member, which is more
correct as they are values of type pid_t.
src/cmd/ksh93/sh/subshell.c,
src/cmd/ksh93/sh/xec.c:
- Update the ${.sh.subshell} increases/decreases to refer to
shgd->realsubshell (a.k.a. shp->gd->realsubshell).
*** To fix ${.sh.level} after changing nv_isnull():
src/cmd/ksh93/sh/macro.c: varsub():
- Add a specific exception for SH_LEVLNOD to the nv_isnull() test,
so that ${.sh.level} is always considered to be set. Its handling
throughout the code is too complex/special for a simple fix, so
we have to special-case it, at least for now.
*** Regression test additions:
src/cmd/ksh93/tests/attributes.sh:
- Add in missing short integer tests and correct the one that
existed. The -si test now yields 'typeset -x -r -s -i foo'
instead of 'typeset -x -r -s -i foo=0' which brings it in line
with all the others.
- Add in some other -l attribute tests for floats. Note, -lX test
was not added as the size of long double is platform dependent.
src/cmd/ksh93/tests/variables.sh:
- Add tests for ${x=y} and ${x:=y} used on short int variables.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
Symptoms of this bug below. These only seem to occur on Linux and
only if you replace your initial login shell by ksh using 'exec'.
1. An erroneous 'Interrupt' message is printed after stopping the
read builtin in a script. Reproducer:
$ exec arch/*/bin/ksh
$ cat ./reproducer.sh
#!/bin/sh
read foo
$ ./reproducer.sh
^C$ <Enter>
[1] + Interrupt ../reproducer.sh
2. Ctrl+C fails to stop /bin/package make. Reproducer:
$ exec arch/*/bin/ksh
$ mv arch arch.old
$ bin/package make
# Press Ctrl+C multiple times
Analysis: In 41ebb55a, I made an error in changing job_init() to
work correctly on non-interactive shells. This line from before:
552| if(possible = (setpgid(0,job.mypgid)>=0) || errno==EPERM)
was changed to:
555| possible = (setpgid(0,job.mypgid) >= 0);
556| if(sh_isoption(SH_INTERACTIVE) && (possible || errno==EPERM))
That is wrong. Before, 'possible' was set to 1 (true) if setpgid()
either succeeded or failed with EPERM. After, it is only set to 1
if setpgid() succeeds. As a result, job control initialisation is
aborted later on upon a test for non-zero 'possible'.
src/cmd/ksh93/sh/jobs.c: job_init():
- Once again set possible to 1 even if setpgid() fails with EPERM.
Thanks to @JohnoKing for the bug report and reproducers.
Resolves: https://github.com/ksh93/ksh/issues/210
The fix for '.' and '..' in regular globbing broke '.' and '..' in
globstar. No globstar pattern that contains '.' or '..' as any
pathname component still matched. This commit fixes that.
This commit also makes symlink/** mostly work, which it never has
done in any ksh93 version. It is correct and expected that symlinks
found by patterns are not resolved, but symlinks were not resolved
even when specified as explicit non-pattern pathname components.
For example, /tmp/** breaks if /tmp is a symlink (e.g. on macOS),
which looks like a bug.
src/lib/libast/include/glob.h,
src/lib/libast/misc/glob.c: glob_dir():
- Make symlink/** work. we can check if the string pointed to by
pat is exactly equal to *. If so, we are doing regular globbing
for that particular pathname element, and it's okay to resolve
symlinks. If not (if it's **), we're doing globstar and we should
not be matching symlinks.
- Let's also introduce proper identification of symlinks (GLOB_SYM)
and not lump them in with other special files (GLOB_DEV).
- Fix the bug with literal '.' and '..' components in globstar
patterns. In preceding code, the matchdir pointer gets set to the
complete glob pattern if we're doing globstar for the current
pathname element, null if not. The pat pointer gets set to the
elements of the pattern that are still left to be processed;
already-done elements are trimmed from it by increasing the
pointer. So, to do the right thing, we need to make sure that '.'
or '..' is skipped if, and only if, it is the final element in
the pattern (i.e., if pat does not contain a slash) and is not
specified literally as '.' or '..', i.e., only if '.' or '..' was
actually resolved from a glob pattern. After this change,
'**/.*', '**/../.*', etc. do the right thing, showing all your
hidden files and directories without undesirable '.' and '..'
results; '.' and '..' are skipped as final elements, unless you
literally specify '**/.', '**/..', '**/foo/bar/..', etc.
src/cmd/ksh93/COMPATIBILITY:
- Note the symlink/** globstar change.
src/cmd/ksh93/sh.1:
- Try to document the current globstar behaviour more exhausively.
src/cmd/ksh93/tests/glob.sh:
- Add tests. Try to cover all the corner cases.
src/cmd/ksh93/tests/shtests:
- Since tests in glob.sh do not use err_exit, they were not
counted. Special-case glob.sh for counting the tests: count the
lines starting with a test_* function call.
Resolves: https://github.com/ksh93/ksh/issues/146
Analysis: When a syntax error occurs, the shell performs a
longjmp(3) back to exfile() in main.c on line 417:
415| if(jmpval)
416| {
417| Sfio_t *top;
418| sh_iorestore((void*)shp,0,jmpval);
419| hist_flush(shp->gd->hist_ptr);
420| sfsync(shp->outpool);
The first thing it does is restore the file descriptor state
(sh_iorestore), then it flushes the history file (hist_flush), then
it synchronises sfio's logical stream state with the physical
stream state using (sfsync).
However, the fix applied in e999f6b1 caused sh_iorestore() to sync
all sfio streams unconditionally. So this was done before
hist_flush(), which caused unpredictable behaviour, including
temporary and/or permanent history corruption, as this also synched
shp->outpool before hist_flush() had a chance to do its thing.
The fix is to only call sfsync() in sh_iorestore() if we're
actually about to call ftruncate(2), and not otherwise.
Moral of the story: bug fixes should be as specific as possible to
minimise the risk of side effects.
src/cmd/ksh93/sh/io.c: sh_iorestore():
- Only call sfsync() if we're about to truncate a file.
src/cmd/ksh93/tests/pty.sh:
- Add test.
Thanks to Marc Wilson for reporting the bug and to Johnothan King
for finding the commit that introduced it.
Resolves: https://github.com/ksh93/ksh/issues/209
Relevant: https://github.com/att/ast/issues/61
src/cmd/ksh93/edit/edit.c: ed_read():
- The loop that handles SIGWINCH assumes sfpkrd will return and
set errno to EINTR if ksh is sent SIGWINCH. This only occurs
when select(2) is used to wait for input, so tell sfpkrd to
use select if possible. This is only done if the last argument
given to sfpkrd is '2', which should avoid regressions.
src/lib/libast/sfio/sfpkrd.c: sfpkrd():
- Always use select if the last argument is 2. This allows
sfpkrd() to intercept SIGWINCH when necessary.
Fixes: https://github.com/ksh93/ksh/issues/202
These POSIX expansions first assign y to x if x is unset or empty,
respectively, and then they yield the value of x. This was not
working on any ksh93 version if x was typeset as numeric (integer
or float) but still unset, as in not assigned a value.
$ unset a; typeset -i a; printf '%q\n' "${a:=42}" "$a"
0
''
Expected output:
42
42
src/cmd/ksh93/sh/macro.c:
- Fix the test for set/unset variable. It was broken because it
only checked for the existence of the node, which exists after
'typeset', but did not check if a value had been assigned. This
additional check needs to be done with the nv_isnull() macro, but
only for expansions of the regular M_BRACE type. Special
expansions cannot have an unset state.
- As of commit 95294419, we know that an nv_optimize() call may be
needed before using nv_isnull() if the shell is compiled with
SHOPT_OPTIMIZE. Move the nv_optimize() call from that commit
forward to before the new check that calls nv_isnull(), and only
bother with it if the type is M_BRACE.
src/cmd/ksh93/tests/variables.sh:
- Add tests for this bug. Test float and integer, and also check
that ${a=b} and ${a:=b} correctly treat the value of 'b' as an
arithmetic expression of which the result is assigned to 'a' if
'a' was typeset as numeric.
src/cmd/ksh93/tests/attributes.sh,
src/cmd/ksh93/tests/comvar.sh,
src/cmd/ksh93/tests/nameref.sh,
src/cmd/ksh93/tests/types.sh:
- Fix a number of tests to report failures correctly.
Resolves: https://github.com/ksh93/ksh/issues/157
The old Bourne shell failed to check for closing quotes and command
substitution backticks when encountering end-of-file in a parser
context (such as a script). ksh93 implemented a hack for partial
compatibility with this bug, tolerating unbalanced quotes and
backticks in backtick command subsitutions, 'eval', and command
line invocation '-c' scripts only.
This hack became broken for backtick command substitutions in
fe20311f/350b52ea as a memory leak was fixed by adding a newline to
the stack at the end of the command substitution. That extra
newline becomes part of any string whose quotes are not properly
terminated, causing problems such as the one detailed here:
https://www.mail-archive.com/ast-developers@lists.research.att.com/msg01889.html
$ touch abc
$ echo `ls "abc`
ls: abc
: not found
No other fix for the memory leak is known that doesn't cause other
problems. (The alternative fix detailed in the referenced mailing
list post causes a different corner-case regression.)
Besides, the hack has always caused other corner case bugs as well:
$ ksh -c '((i++'
Actual: ksh: i++(: not found
(If an external command 'i++(' existed, it would be run)
Expect: ksh: syntax error at line 1: `(' unmatched
$ ksh -c 'i=0; echo $((++i'
Actual: (empty line; the arithmetic expansion is ignored)
Expect: ksh: syntax error at line 1: `(' unmatched
$ ksh -c 'echo $(echo "hi)'
Actual: ksh: syntax error at line 1: `(' unmatched
Expect: ksh: syntax error at line 1: `"' unmatched
So, it's time to get rid of this hack. The old Bourne shell is
dead and buried. No other shell tries to support this breakage.
Tolerating syntax errors is just asking for strange side effects,
inconsistent states, and corner case bugs. We should not want to do
that. Old scripts that rely on this will just need to be fixed.
src/cmd/ksh93/sh/lex.c:
- struct lexdata: Remove 'char balance' member for remembering an
unbalanced quote or backtick.
- sh_lex(): Remove the back to remember and compensate for
unbalanced quotes/backticks that was executed only if we were
executing a script from a string, as opposed to a file.
src/cmd/ksh93/COMPATIBILITY:
- Note the change.
Resolves: https://github.com/ksh93/ksh/issues/199
This commit fixes an arbitrary command execution vulnerability in
array subscripts used within the arithmetic subsystem.
One of the possible reproducers is:
var='1$(echo INJECTION >&2)' ksh -c \
'typeset -A a; ((a[$var]++)); typeset -p a'
Output before this commit:
INJECTION
typeset -A a=([1]=1)
The 'echo' command has been surreptitiously executed from an
external environment variable.
Output after this commit:
typeset -A a=(['1$(echo INJECTION >&2)']=1)
The value is correctly used as an array subscript and nothing in it
is parsed or executed. This is as it should be, as ksh93 supports
arbitrary subscripts for associative arrays.
If we think about it logically, the C-style arithmetic subsystem
simply has no business messing around with shell expansions or
quoting at all, because those don't belong to it. Shell expansions
and quotes are properly resolved by the main shell language before
the arithmetic subsystem is even invoked. It is particularly
important to maintain that separation because the shell expansion
mechanism also executes command substitutions.
Yet, the arithmetic subsystem subjected array subscripts that
contain `$` (and only array subscripts -- how oddly specific) to
an additional level of expansion and quote resolution. For some
unfathomable reason, there are two lines of code doing specifically
this. The vulnerability is fixed by simply removing those.
Incredibly, variants of this vulnerability are shared by bash, mksh
and zsh. Instead of fixing it, it got listed in Bash Pitfalls!
http://mywiki.wooledge.org/BashPitfalls#y.3D.24.28.28_array.5B.24x.5D_.29.29
src/cmd/ksh93/sh/arith.c:
- scope(): Remove these two lines that implement the vulnerability.
if(strchr(sub,'$'))
sub = sh_mactrim(shp,sub,0);
- scope(), arith(): Remove the NV_SUBQUOTE flag from two
nv_endsubscript() calls. That flag causes the array subscript to
retain the current level of shell quoting. The shell quotes
everything as in "double quotes" before invoking the arithmetic
subsystem, and the bad sh_mactrim() call removed one level of
quoting. Since we're no longer doing that, this flag should no
longer be passed, or subscripts may get extra backslash escapes.
src/cmd/ksh93/include/name.h,
src/cmd/ksh93/sh/array.c:
- nv_endsubscript(): The NV_SUBQUOTE flag was only passed from
arith.c. Since it is now unused, remove it.
src/cmd/ksh93/tests/arith.sh:
- Tweak some tests: fix typos, report wrong values.
- Add 21 tests. Most are based on reproducers contributed by
@stephane-chazelas and @hyenias. They verify that this
vulnerability is gone and that no quoting bugs were introduced.
Resolves: https://github.com/ksh93/ksh/issues/152
Corrected the size of attribute(s) being overwritten with 0 when
'readonly' or 'typeset -r' was applied to an existing variable. Since
one cannot set any attributes with the 'readonly' command, its function
call to setall() needs to be adjusted to acquire the current size from
the old size or existing size of the variable. A plain 'typeset -r' is
the same as 'readonly' in that it needs to load the old size as its
current size for use in the subsequent to call to nv_newattr().
src/cmd/ksh93/bltins/typeset.c: setall():
- Both 'readonly' and 'typeset -r' end up calling setall(). setall()
has full visibility into all user supplied values and existing
values that are needed to differentiate whereas name.c newattr()
acquires combined state flags.
- Added a conditional check if the readonly flag was requested by
user then meets the criteria of having present size of 0, cannot
be a numeric nor binary string, and is void of presence of any of
the justified string attributes.
- -L/R/Z justified string attributes if not given a value default
to a size of 0 which means to autosize. A binary string can have
a fixed field size, e.g. -bZ. The present of any of the -L/R/Z
attribules means that current size is valid and should be used
even if it is zero.
src/cmd/ksh93/tests/attributes.sh:
- Added various tests to capture and reiterate that 'readonly' should
be equivalent to 'typeset -r' and applying them should not alter the
previous existing size unless additional attributes are set along
with typeset command.
The value of the ${.sh.fun} variable, which is supposed to contain
the name of the function currently being executed, leaks out of the
DEBUG trap if it executes a function. Reproducer:
$ fn() { echo "executing the function"; }
$ trap fn DEBUG
$ trap - DEBUG
executing the function
$ echo ${.sh.fun}
fn
${.sh.fun} should be empty outside the function.
Annalysis:
The sh_debug() function in xec.c, which executes the DEBUG trap
action, contains these lines, which are part of restoring the state
after running the trap action with sh_trap():
nv_putval(SH_PATHNAMENOD,shp->st.filename,NV_NOFREE);
nv_putval(SH_FUNNAMENOD,shp->st.funname,NV_NOFREE);
shp->st = savst;
First the SH_PATHNAMENOD (${.sh.file}) and SH_FUNNAMENOD
(${.sh.fun}) variables get restored from the values in the shell's
scoped information struct (shp->st), but that is done *before*
restoring the parent scope with 'shp->st = savst;'. It should be
done after. Fixing the order is sufficient to fix the bug.
However, I am not convinced that these nv_putval() calls are good
for anything at all. Setting, unsetting, restoring, etc. the
${.sh.fun} and ${.sh.file} variables is already being handled
perfectly well elsewhere in the code for executing functions and
sourcing dot scripts. The DEBUG trap is neither here nor there.
There's no reason for it to get involved with these variables.
I was unable to break anything after simply removing those two
lines. So I strongly suspect this is another case, out of many now,
where a bug in ksh93 is properly fixed by removing some code.
I couldn't get ${.sh.file} to leak similarly -- I think this is
because SH_PATHNAMENOD (and not SH_FUNNOD) is set explicitly in
exfile() in main.c, masking this incorrect restore. It is the only
place where SH_PATHNAMENOD and SH_FUNNOD are not both set.
src/cmd/ksh93/sh/xec.c:
- Remove these two spurious nv_putval() calls.
src/cmd/ksh93/tests/variables.sh:
- Add regression test for leaking ${.sh.fun}.
1. The editor accepted literal tabs without escaping in certain
cases, causing buggy and inconsistent completion behaviour.
https://github.com/ksh93/ksh/issues/71#issuecomment-656970959https://github.com/ksh93/ksh/issues/71#issuecomment-657216472
2. After completing a filename by choosing from a file completion
menu, the terminal cursor was placed one position too far to the
right, corrupting command line display. This happened with
multiline active.
https://github.com/ksh93/ksh/issues/71#issue-655093805
3. A completion menu was displayed if the file name to be completed
was at the point where the rest of it started with a number,
even if that part uniquely identified it so the menu had 1 item.
https://www.mail-archive.com/ast-users@lists.research.att.com/msg00436.html
src/cmd/ksh93/edit/emacs.c:
- Cosmetic consistency: change two instances of cntl('[') to ESC.
- ed_emacsread(): Fix number 1 by refusing to continue into default
processing if a tab character was not used for tab completion.
Instead, beep and continue to the next read loop iteration. This
behaviour is consistent with most other shells, so I doubt there
will be objections. To enter a literal tab it's simple enough to
escape it with ^V (the 'stty lnext' character) or \.
- draw(): Fix number 2 by correcting an off-by-one error in the
ed_setcursor() call that updates the terminal's cursor display
in multiline mode. The 'old' and 'new' parameters need to have
identical values in this particular call to avoid the cursor
position being off by one to the right. This change makes it
match the corresponding ed_setcursor() call in vi.c. See below*
for details. Thanks to Lev Kujawski for the help in analysing.
src/cmd/ksh93/edit/completion.c: ed_expand():
- Fix number 3 by changing from '=' mode (menu-based completion) to
'\' mode (ordinary filename completion) if the menu would only
show one option, which was pointless and annoying. This never
happened in vi mode, so possibly the ed_expand() call in emacs.c
could have been improved instead. But I'm comfortable with fixing
it here and not in emacs.c, because this fixes it at a more
fundamental level, plus it's straightforward and obvious here.
Resolves: https://github.com/ksh93/ksh/issues/71
____
* Further details on bug number 2:
At https://github.com/ksh93/ksh/issues/71#issuecomment-786391565
Martijn Dekker wrote:
> I'm back to my original hypothesis that there is somehow an
> off-by-one error related to the ed_setcursor() call that gets
> executed when in multiline mode. I cannot confirm whether that
> off-by-one error is actually in the call itself, or occurs
> sometime earlier on one of the many possible occasions where
> ep->cursor is changed. But everything else appears to work
> correctly, so it's not unlikely that the problem is in the call
> itself.
>
> For reference, this is the original version of that call in
> emacs.c:
>
> ksh/src/cmd/ksh93/edit/emacs.c
> Lines 1556 to 1557 in df2b9bf
> if(ep->ed->e_multiline && option == REFRESH)
> ed_setcursor(ep->ed, ep->screen, ep->cursor-ep->screen, ep->ed->e_peol, -1);
>
> There is a corresponding call in the vi.c refresh() function
> (which does the same thing as draw() in emacs.c), where the third
> (old) and fourth (new) arguments are actually identical:
>
> ksh/src/cmd/ksh93/edit/vi.c
>
> Lines 2086 to 2087 in df2b9bf
> if(vp->ed->e_multiline && vp->ofirst_wind==INVALID)
> ed_setcursor(vp->ed, physical, last_phys+1, last_phys+1, -1);
>
> The expectation for this particular call is in fact that they
> should be identical, so that a delta of zero is calculated in
> that function. Delta not being zero is what causes the cursor to
> be positioned wrong.
>
> In vi.c, last_phys is a macro that is defined as editb.e_peol,
> and editb is a macro that is defined as (*vp->ed). Which means
> last_phys means vp->ed->e_peol, which is the same as
> ep->ed->e_peol in emacs.c. (These editors were originally
> separate programs by different authors, and I suppose this is how
> it shows. Korn didn't want to change all the variable names to
> integrate them, so made macros instead.)
>
> That leaves the question of why vi.c adds 1 to both last_phys
> a.k.a. e_peol arguments, and emacs.c uses e_peol for new without
> adding anything. Analysing the ed_setcursor() code could answer
> that question.
>
> So, this patch makes emacs.c do it the same way vi.c does. Let's
> make the third argument identical to the fourth. My brief testing
> shows the bug is fixed, and the regression tests yield no
> failures. This fix is also the most specific change possible, so
> there are few opportunities for side effects (I hope).
At https://github.com/ksh93/ksh/issues/71#issuecomment-786466652
Lev Kujawski wrote:
> I did a bit of research on this, and I think the fix to have the
> Emacs editing mode do the same as Vi is correct.
>
> From RELEASE:
> 08-05-01 In multiline edit mode, the refresh operation will now clear
> the remaining portion of the last line.
>
> Here's a fragment from the completion.c of the venerable but
> dated CDE DtKsh:
>
> else
> while (*com)
> {
> *out++ = ' ';
> out = strcopy(out,*com++);
> }
> *cur = (out-outbuff);
> /* restore rest of buffer */
> out = strcopy(out,stakptr(0));
> *eol = (out-outbuff);
>
> Noticeably missing is the code to add a space after file name
> completions. So, it seems plausible that if multiline editing
> mode was added beforehand,the ep->ed->p_eol !=
> ep->cursor-ep->screen case might never have occurred during
> testing.
>
> Setting the 'first' parameter to -1 seems to be a pretty explicit
> indicator that the author(s) intended the line clearing code to
> run, hence the entry in RELASE.
>
> The real issue is that if we update the cursor by calling
> ed_setcursor on line 1554 with old != new, the later call to
> setcursor on line 1583, here:
>
> I = (ncursor-nscreen) - ep->offset;
> setcursor(ep,i,0);
>
> will use outdated screen information to call setcursor, which,
> coincidentally, calls ed_setcursor.
In the emacs editor:
1. press ESC
2. change the size of your terminal window
and your screen is mysteriously cleared. (Until recent fixes, the
shell probably also crashed somewhere in the job control code.)
The cause is the way SIGWINCH is handled by ed_read() in edit.c.
For the emacs editor, it sends a Ctrl+L character to the input
buffer. The Ctrl+L command refreshes the command line. And it so
happens that ESC plus Ctrl+L is a command to clear the screen in
the emacs editor.
With the exeption of vi insert/command mode for which it uses a
shared flag, edit.c does not know the state of the editor, because
their data are internal to emacs.c and vi.c. So it doesn't know
whether you're in some mode that treats keyboard input specially.
Which means this way of dealing with SIGWINCH is fundamentally
misdesigned and is not worth fixing.
It gets sillier: in addition to sending keyboard commands, edit.c
was also communicating directly with emacs.c and vi.c via a flag,
e_nocrnl, which means 'please don't make Ctrl+L emit a linefeed'
(it normally refreshes on a new line but that is undesirable for
SIGWINCH). So there is already a hack that breaks the barrier
between edit.c and emacs.c/vi.c. Let's do that properly instead.
As of this commit, ed_read() does not send any fake keystrokes.
Instead, two extern functions, emacs_redraw() and vi_redraw(), are
defined for redrawing the command line. These are put in emacs.c
and vi.c so they have access to relevant static data and functions.
Then, instead of sending keyboard commands to the editor and
returning, ed_read() simply calls the redraw function for the
active editor, then continues and waits for input. Much cleaner.
src/cmd/ksh93/include/edit.h:
- Remove e_nocrnl flag from Edit_t struct.
- Define externs emacs_redraw() and vi_redraw(). Since Emacs_t and
Vi_t types are not known here, we have to declare void* pointers
and the functions will have to use typecasts.
src/cmd/ksh93/edit/edit.c:
- ed_read(): Call emacs_redraw() or vi_redraw() as per above.
- ed_getchar(): Remove comment about a nonexistent while loop.
src/cmd/ksh93/edit/emacs.c:
- Updates corresponding to removal of e_nocrnl flag.
- Add emacs_redraw(). This one is pretty simple. Refresh the
command line, then ed_flush() to update the cursor display.
src/cmd/ksh93/edit/vi.c:
- Updates corresponding to removal of e_nocrnl flag. Also remove a
similar internal 'nonewline' flag which is now equally redundant.
- Move the Ctrl+L handling code (minus writing the newline) into
the vi_redraw() function.
- Change two cases where vi set nonewline and sent Ctrl+L to itself
into simple vi_redraw() calls.
- Add vi_redraw(). This is more complicated as it incorporates the
previous Ctrl+L code. It needs an added refresh() call with a
check whether we're currently in command or insert mode, as those
use different refresh methods. Luckily edit.c already maintains
an *e_vi_insert flag in ed_getchar() that we can use. Since vi's
refresh() already calls ed_flush(), we don't need to add that.
ksh crashed in various different and operating system-dependent
ways when attempting to create or apply justification strings
using typeset -L/-R/-Z, especially if large sizes are used.
The crashes had two immediate causes:
- In nv_newattr(), when applying justification attributes, a buffer
was allocated for the justified string that was exactly 8 bytes
longer than the original string. Any larger justification string
caused a buffer overflow (!!!).
- In nv_putval(), when applying existing attributes to a new value,
the corresponding memmove() either did not zero-terminate the
justified string (if the original string was longer than the
justified string) or could read memory past the original string
(if the original string was shorter than the justified string).
Both scenarios can cause a crash.
This commit fixes other minor issues as well, such as a mysterious
8 extra bytes allocated by several malloc/realloc calls. This may
have been some naive attempt to paper over the above bugs. It seems
no one can make any other kind of sense of it.
A readjustment bug with zero-filling was also fixed.
src/cmd/ksh93/sh/name.c:
- nv_putval():
. Get rid of the magical +8 bytes for malloc and realloc. Just
allocate one extra byte for the terminating zero.
. Fix the memmove operation to use strncpy instead, so that
buffer overflows are avoided in both scenarios described above.
Also make it conditional upon a size adjustment actually
happening (i.e. if 'dot' is nonzero).
. Mild refactoring: combine two 'if(sp)' blocks into one;
declare variables only used there locally for legibility.
- nv_newattr():
* Replace the fatally broken "let's allocate string length + 8
bytes no matter the size of the adjustment" routine with a new
one based on work by @hyenias (see comments in #142). It is
efficient with memory, taking into account numeric types,
growing strings, and shrinking strings.
* Fix zero-filling in readjustment after changing the initial
size of a -Z attribute. If the number was zero, all zeros were
still skipped, leaving an empty string.
Thanks to @hyenias for originally identifying this breakage and
laying the groundwork for fixing nv_newattr(), and to @lijog for
the crash analysis that revealed the key to the nv_putval() fix.
Resolves: https://github.com/ksh93/ksh/issues/142
Resolves: https://github.com/ksh93/ksh/issues/181
So now we know what that faulty check for shp->indebug in sh_trap()
was meant to do: it was meant to pass down the trap handler's exit
status, via sh_debug(), down to sh_exec() (xec.c) so that it could
then skip the execution of the next command if the trap's exit
status is 2, as documented in the manual page. As of d00b4b39, exit
status 2 was not passed down, so this stopped working.
This commit reinstates that functionality, but without the exit
status bug in command substitutions caused by the old way.
src/cmd/ksh93/sh/fault.c: sh_trap():
- Save the trap's exit status before restoring the parent
envionment's exit status. Make this saved exit status the return
value of the function. (This does not break anything, AFAICT; the
majority of sh_trap() calls ignore the return value, and the few
that don't ignore it seem to expect it to return exactly this.)
src/cmd/ksh93/sh/xec.c: sh_exec():
- The sh_trap() fix has one side effect: whereas the exit status of
a skipped command was always 2 (as per the trap handler), now it
is always 0, because it gets reset in sh_exec() but no command is
executed. That is probably not a desirable change in behaviour,
so let's fix that here instead: set sh.exitval to 2 when skipping
commands.
src/cmd/ksh93/sh.1:
- Document that ${.sh.command} shell-quotes its arguments for use
by 'eval' and such. This fact was not documented anywhere, AFAIK.
src/cmd/ksh93/shell.3:
- Document that $? (exit status) is made local to trap handlers.
- Document that sh_trap() returns the trap handler's exit status.
src/cmd/ksh93/tests/basic.sh:
- Add test for this bug.
- Add a missing test for the exit status 255 functionality (if a
DEBUG trap handler yields this exit status and we're executing a
function or dot script, a return is triggered).
Fixes: https://github.com/ksh93/ksh/issues/187
This commit fixes a bug in the 'read' built-in: it did not properly
skip over multibyte characters. The bug never affects UTF-8 locales
because all UTF-8 bytes have the high-order bit set. But Shift-JIS
characters may include a byte corresponding to the ASCII backslash
character, which cauased buggy behaviour when using 'read' without
the '-r' option that disables backslash escape processing.
It also makes the regression tests compatible with Shift-JIS
locales. They failed with syntax errors.
src/cmd/ksh93/bltins/read.c:
- Use the multibyte macros when skipping over word characters.
Based on a patch from the old ast-developers mailing list:
https://www.mail-archive.com/ast-developers@lists.research.att.com/msg01848.html
src/cmd/ksh93/include/defs.h:
- Be a bit smarter about causing the compiler to optimise out
multibyte code when SHOPT_MULTIBYTE is disabled. See the updated
comment for details.
src/cmd/ksh93/tests/locale.sh:
- Put all the supported locales in an array for future tests.
- Add test for the 'read' bug. Include it in a loop that tests
64 SHIFT-JIS character combinations. Only one fails on old ksh:
the one where the final byte corresponds to the ASCII backslash.
It doesn't hurt to test all the others anyway.
src/cmd/ksh93/tests/basic.sh,
src/cmd/ksh93/tests/builtins.sh,
src/cmd/ksh93/tests/quoting2.sh:
- Fix syntax errors that occurred in SHIFT-JIS locales as the
parser was processing literal UTF-8 characters. Not executing
that code is not enough; we need to make sure it never gets
parsed as well. This is done by wrapping the commands containing
literal UTF-8 strings in an 'eval' command as a single-quoted
operand.
.github/workflows/ci.yml:
- Run the tests in the ja_JP.SJIS locale instead of ja_JP.UTF-8.
UTF-8 is already covered by the nl_NL.UTF-8 test run; that should
be good enough.
A ${ shared-state command substitution; } (internally called
subshare) is documented to share its state with the parent shell
environment, so all changes made within the command substitution
survive outside of it. However, when it is run within a
virtual/non-forked subshell, variables that are not already local
to that subshell will leak out of it into the grandparent state.
Reproducer:
$ ksh -c '( v=${ bug=BAD; } ); echo "$bug"'
BAD
If the variable pre-exists in the subshell, the bug does not occur:
$ ksh -c '( bug=BAD1; v=${ bug=BAD2; } ); echo "$bug"'
(empty line, as expected)
The problem is that the sh_assignok() function, which is
responsible for variable scoping in virtual subshells, does not
ever bother to create a virtual subshell scope for a subshare.
That is an error if a subshare's parent (or higher-up ancestor)
environment is a virtual subshell, because a scope needs to be
created in that parent environment if none exists.
To make this bugfix possible, first we need to get something out of
the way. nv_restore() temporarily sets the subshell's pointer to
the preesnt working directory, shpwd, to null. This causes
sh_assignok() to assume that the subshell is a subshare (because
subshares don't store their own PWD) and refuse to create a scope.
However, nv_restore() sets it to null for a different purpose: to
temporarily disable scoping for *all* virtual subshells, making
restoring possible. This is a good illustration of why it's often
not a good idea to use the same variable for unrelated purposes.
src/cmd/ksh93/sh/subshell.c:
- Add a global static subshell_noscope flag variable to replace the
misuse of sh.shpwd described above.
- sh_assignok():
. Check subshell_noscope instead of shpwd to see if scope
creation is disabled. This makes it possible to distinguish
between restoring scope and handling subshares.
. If the current environment is a subshare that is in a virtual
subshell, create a scope in the parent subshell. This is done
by temporarily making the parent virtual subshell the current
subshell (by setting the global subshell_data pointer to it)
and calling sh_assignok() again, recursively.
- nv_restore(): To disable subshell scope creation while restoring,
set subshell_noscope instead of saving and unsetting sh.shpwd.
src/cmd/ksh93/tests/subshell.sh:
- Add tests. I like tests. Tests are good.
Fixes: https://github.com/ksh93/ksh/issues/143
This commit fixes the following:
1. Emacs mode ignores --nobackslashctrl (re: 24598fed) when in
reverse search.
2. When entering more than one backslash, emacs reverse search mode
deletes multiple backslashes after pressing backspace once.
Reproducer:
$ set --emacs --nobackslashctrl
$ <Ctrl+R> \\\\<Backspace>
3. Except when in reverse search, the backslash fails to escape a
subsequent interrupt character (^C). Reproducer:
$ set --emacs --backslashctrl
$ teststring \<Ctrl+C>
src/cmd/ksh93/edit/emacs.c:
- Disable escaping backslashes in emacs reverse search if
'nobackslashctrl' is enabled.
- Fix the buggy behavior of backslashes in emacs reverse
search by processing backslashes in a loop.
src/cmd/ksh93/tests/pty.sh:
- Add regression tests.
src/cmd/ksh93/sh.1:
- Fix a minor documentation error (^C is the usual interrupt
character, not ^?).
Co-authored-by: Martijn Dekker <martijn@inlv.org>
'case x in esac' should be syntactically correct, but was an error:
$ ksh -c 'case x in esac'
ksh: syntax error at line 1: `case' unmatched
Inserting a newline was a workaround:
$ ksh -c $'case x in\nesac'
(no output)
The problem was that the 'esac' reserved word was not being
recognised if it immediately followed the 'in' reserved word.
src/cmd/ksh93/sh/lex.c: sh_lex():
- Do not turn off recognition of reserved words after 'in' if we're
in a 'case' construct; only do this for 'for' and 'select'.
src/cmd/ksh93/tests/case.sh:
- Add seven regression test for correct recognition of 'esac'.
Only two failed on ksh93. The rest is to catch future bugs.
Fixes: https://github.com/ksh93/ksh/issues/177
This commit fixes the functionality of Alt+D and Alt+H in emacs mode.
These keyboard shortcuts are intended to work on whole words, but
after commit 13c3fb21 their functionality was reduced to deleting only
singular letters:
$ Test word <Alt+H> # This should delete 'word', not just 'd'.
$ Foo <Alt+B> <Alt+D> # This should delete 'Foo', not just 'F'.
Man page entries for reference:
M-d Delete current word.
M-^H (Meta-backspace) Delete previous word.
M-h Delete previous word.
src/cmd/ksh93/edit/emacs.c:
- 'count' cannot be overridden when handling Alt+D or Alt+H,
so add the total number of repetitions to count (the number of
repetitions can't be negative).
- If 'count' is a negative number, set it to one before adding the
number of repetitions.
The following emacs editor 'feature' kept making me want to go back
to bash. I forget a backslash escape in a command somewhere. So I
go back to insert it. I type the \, then want to go forward. My
right arrow key, instead of moving the cursor, then replaces my
backslash with garbage. Why? The backslash escapes the following
control character at the editor level and inserts it literally.
The vi editor has a variant of this which is much less harmful. It
only works in insert mode and the backslash only escapes the next
kill or erase character.
In both editors, this feature is completely redundant with the
'stty lnext' character which is ^V by default -- and works better
as well because it also escapes ^C, ^J (linefeed) and ^M (Return).
[In fact, you could even issue 'stty lnext \\' and get a much more
consistent version of this feature on any shell. You have to type
two backslashes to enter one, but it won't kill your cursor keys.]
If it were up to me alone, I'd simply remove this misfeature from
both editors. However, it is long-standing documented behaviour.
It's in the 1995 book. Plus, POSIX specifies the vi variant of it.
So, this adds a shell option instead. It was quite trivial to do.
Now I can 'set --nobackslashctrl' in my ~/.kshrc. What a relief!
Note: To keep .kshrc compatibile with older ksh versions, use:
command set --nobackslashctrl 2>/dev/null
src/cmd/ksh93/include/shell.h,
src/cmd/ksh93/data/options.c:
- Add new SH_NOBACKSLCTRL/"nobackslashctrl" long-form option. The
"no" prefix shows it to the user as "backslashctrl" which is on
by default. This avoids unexpectedly changing historic behaviour.
src/cmd/ksh93/edit/emacs.c: ed_emacsread(),
src/cmd/ksh93/edit/vi.c: getline():
- Only set the flag for special backslash handling if
SH_NOBACKSLCTRL is off.
src/cmd/ksh93/sh.1,
src/cmd/ksh93/data/builtins.c:
- Document the new option (as "backslashctrl", on by default).
Other minor tweaks:
src/cmd/ksh93/edit/edit.c:
- ed_setup(): Add fallback #error if no tput method is set. This
should never be triggered; it's to catch future editing mistakes.
- escape(): cntl('\t') is nonsense as '\t' is already a control
character, so change this to just '\t'.
- xcommands(): Let's enable the ^X^D command for debugging
information on non-release builds.
src/cmd/ksh93/features/cmds:
- The tput feature tests assumed a functioning terminal in $TERM.
However, for all we know we might be compiling with no tty and
TERM=dumb. The tput commands won't work then. So set TERM=ansi
to use a standard default.
This fixes the following:
1. 'set --posix' now works as an equivalent of 'set -o posix'.
2. The posix option turns off braceexpand and turns on letoctal.
Any attempt to override that in a single command such as 'set -o
posix +o letoctal' was quietly ignored. This now works as long
as the overriding option follows the posix option in the command.
3. The --default option to 'set' now stops the 'posix' option, if
set or unset in the same 'set' command, from changing other
options. This allows the command output by 'set +o' to correctly
restore the current options.
src/cmd/ksh93/data/builtins.c:
- To make 'set --posix' work, we must explicitly list it in
sh_set[] as a supported option so that AST optget(3) recognises
it and won't override it with its own default --posix option,
which converts the optget(3) string to at POSIX getopt(3) string.
This means it will appear as a separate entry in --man output,
whether we want it to or not. So we might as well use it as an
example to document how --optionname == -o optionname, replacing
the original documentation that was part of the '-o' description.
src/cmd/ksh93/sh/args.c: sh_argopts():
- Add handling for explitit --posix option in data/builtins.c.
- Move SH_POSIX syncing SH_BRACEEXPAND and SH_LETOCTAL from
sh_applyopts() into the option parsing loop here. This fixes
the bug that letoctal was ignored in 'set -o posix +o letoctal'.
- Remember if --default was used in a flag, and do not sync options
with SH_POSIX if the flag is set. This makes 'set +o' work.
src/cmd/ksh93/include/argnod.h,
src/cmd/ksh93/data/msg.c,
src/cmd/ksh93/sh/args.c: sh_printopts():
- Do not potentially translate the 'on' and 'off' labels in 'set
-o' output. No other shell does, and some scripts parse these.
src/cmd/ksh93/sh/init.c: sh_init():
- Turn on SH_LETOCTAL early along with SH_POSIX if the shell was
invoked as sh; this makes 'sh -o' and 'sh +o' show expected
options (not that anyone does this, but correctness is good).
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/include/shell.h:
- The state flags were in defs.h and most (but not all) of the
shell options were in shell.h. Gather all the shell state and
option flag definitions into one place in shell.h for clarity.
- Remove unused SH_NOPROFILE and SH_XARGS option flags.
src/cmd/ksh93/tests/options.sh:
- Add tests for these bugs.
src/lib/libast/misc/optget.c: styles[]:
- Edit default optget(3) option self-documentation for clarity.
Several changed files:
- Some SHOPT_PFSH fixes to avoid compiling dead code.
If I haven't missed anything, this should make the non-interactive
aspects of job control in scripts work as expected, except for the
"<command unknown>" issue in the output of 'bg', 'fg' and 'jobs'
(which is not such a high priority as those commands are really
designed for interactive use).
Plus, I believe I now finally understand what these three are for:
* The job.jobcontrol variable is set to nonzero by job_init() in
jobs.c if, and only if, the shell is interactive *and* managed to
get control of the terminal. Therefore, any changing of terminal
settings (tcsetpgrp(3), tty_set()) should only be done if
job.jobcontrol is nonzero. This commit changes several checks for
sh_isoption(SH_INTERACTIVE) to checks for job.jobcontrol for
better consistency with this.
* The state flag, sh_isstate(SH_MONITOR), determines whether the
bits of job control that are relevant for both scripts and
interactive shells are active, which is mostly making sure that a
background job gets its own process group (setpgid(3)).
* The shell option, sh_isoption(SH_MONITOR), is just that. When the
user turns it on or off, the state flag is synched with it. It
should usually not be directly checked for, as the state may be
temporarily turned off without turning off the option.
Prior discussion:
https://www.mail-archive.com/austin-group-l@opengroup.org/msg06456.html
src/cmd/ksh93/bltins/typeset.c, src/cmd/ksh93/sh/args.c:
- Move synching the SH_MONITOR state flag with the SH_MONITOR
shell option from b_set() (the 'set' builtin) to sh_applyopts()
which is indirectly called from b_set() and is also used when
parsing the shell invocation command line. This ensures -m is
properly enabled in both scenarios.
src/cmd/ksh93/sh/jobs.c:
- job_init(): Do not refuse to initialise job control on
non-interactive shells. Instead, skip everything that should only
be done on interactive shells (i.e., everything to do with the
terminal). This function is now even more of a mess than it was
before, so refactoring may be desirabe at some point.
- job_close(), job_set(), job_reset(), job_wait(): Do not reset the
terminal process group (tcsetpgrp()) if job.jobcontrol isn't on.
src/cmd/ksh93/sh/xec.c:
- sh_exec(): TFORK: For SIGINT handling, check the SH_MONITOR
state flag, not the shell option.
- sh_exec(): TFORK: Do not turn off the SH_MONITOR state flag in
forked children. The non-interactive part of job control should
stay active. Instead, turn off the SH_INTERACTIVE state flag so
we don't get interactive shell behaviour (i.e. job control noise
on the terminal) in forked subshells.
- _sh_fork(), sh_ntfork(): Do not reset the terminal process group
(tcsetpgrp()) if job.jobcontrol isn't on. Do not turn off the
SH_MONITOR state flag in forked children.
src/cmd/ksh93/sh/subshell.c: sh_subfork():
- Do not turn off the monitor option and state in forked subshells.
The non-interactive part of job control should stay active.
src/cmd/ksh93/bltins/misc.c: b_bg():
- Check isstate(SH_MONITOR) instead of sh_isoption(SH_MONITOR) &&
job.jobcontrol before throwing a 'no job control' error.
This fixes a minor bug: fg, bg and disown could quietly fail.
src/cmd/ksh93/tests/jobs.sh:
- Add tests for 'fg' with job control IDs (%%, %1) in scripts.
- Add test checking that a background job launched from a subsell
with job control enabled correctly becomes the leader of its own
process group.
Makes progress on: https://github.com/ksh93/ksh/issues/119
Another longstanding whopper of a bug in basic ksh93 functionality:
run a ${ shared-state; } command substitution twice and job control
promptly loses track of all your running jobs. New jobs are tracked
again until you run another two shared-state command substitutions.
This is in at least 93t+, 93u-, 93u+, 93v- and ksh2020.
$ sleep 300 &
[1] 56883
$ jobs # OK
[1] + Running sleep 300 &
$ v=${ echo hi1; }
$ jobs # OK
[1] + Running sleep 300 &
$ v=${ echo hi2; }
$ jobs # Nothing!
$ fg
ksh: fg: no such job
src/cmd/ksh93/sh/subshell.c: sh_subshell():
- The current environment number shp->curenv (a.k.a. sh.curenv) was
not being restored if the virtual subshell we're leaving is of
the shared-state command substitution variety as it was wrongly
considered to be part of the environment that didn't need
restoring. This caused it to be out of sync with shp->jobenv
(a.k.a. sh.jobenv) which did get restored from savedcurenv.
Restore both from savedcurenv at the same time for any subshell.
(How these numbers are used exactly remains to be discovered.)
src/cmd/ksh93/tests/jobs.sh:
- Added, with a test for this bug to start it off. There is no
other test script where job control fits, and a lot more related
fixes are anticipated: https://github.com/ksh93/ksh/issues/119
This is some nonsense: redirections that store a file descriptor
greater than 9 in a variable, like {var}<&2 and the like, stopped
working if brace expansion was turned off. '{var}' is not a brace
expansion as it doesn't contain ',' or '..'; something like 'echo
{var}' is always output unexpanded. And redirections and brace
expansion are two completely unrelated things. It wasn't documented
that these redirections require the -B/braceexpand option, either.
src/cmd/ksh93/sh/lex.c: sh_lex():
- Remove incorrect check for braceexpand option before processing
redirections of this form.
src/cmd/ksh93/COMPATIBILITY:
- Insert a brief item mentioning this.
src/cmd/ksh93/sh.1:
- Correction: these redirections do not yield a file descriptor >
10, but > 9, a.k.a. >= 10.
- Add a brief example showing how these redirections can be used.
src/cmd/ksh93/tests/io.sh:
- Add a quick regression test.
This commit corrects how shortint was being applied to various
possible typeset variables in error. The short integer option
modifier 'typeset -s' should only be able to be applied if the
the variable is also an integer. Several issues were resolved
with this fix:
- 'typeset -s': created a short integer having an invalid base
of zero. 'typeset -s foo' created 'typeset -s -i 0 foo=0' and
now will result in an empty string.
- 'typeset -sL': previously resulted in a segmentation fault.
The following are the various incorrect 'typeset' instances
that have been fixed:
$ 'export foo; typeset -s foo; readonly foo; typeset -p foo'
(before) typeset -x -r -s -i 0 foo=0
( after) typeset -x -r foo
$ 'typeset -sL foo=1*2; typeset -p foo'
(before) Segmentation fault (core dumped)
( after) typeset -L 3 foo='1*2'
$ 'typeset -sR foo=1*2; typeset -p foo'
(before) typeset -s -i foo=2
( after) typeset -R 3 foo='1*2'
$ 'typeset -sZ foo=1*2; typeset -p foo'
(before) typeset -F 0 foo=2
( after) typeset -Z 3 -R 3 foo='1*2'
src/cmd/ksh93/bltins/typeset.c: b_typeset():
- Add conditional check within the 's' option to only
apply NV_SHORT as well as remove any NV_LONG flag
if NV_INTEGER flag was set.
- Relocate shortint conditional logic to the 'i' option.
src/cmd/ksh93/tests/attributes.sh:
- Adjust regression tests for '-s' and add '-si' check.
This fixes part of https://github.com/ksh93/ksh/issues/87:
Scalar arrays (-a) and associative arrays (-A) of a type created by
'enum' did not consistently block values not specified by the enum
type, yielding corrupted results.
An expansion of type "${array[@]}" yielded random numbers instead
of values for associative arrays of a type created by 'enum'.
This does not yet fix another problem: ${array[@]} does not yield
all values for associative enum arrays.
src/cmd/ksh93/bltins/enum.c: put_enum():
- Always throw an error if the value is not in the list of possible
values for an enum type. Remove incorrect check for the NV_NOFREE
flag. Whatever that was meant to accomplish, I've no idea.
src/cmd/ksh93/sh/array.c: nv_arraysettype():
- Instead of sh_eval()ing a shell assignment, use nv_putval()
directly. Also use the stack (see src/lib/libast/man/stk.3)
instead of malloc to save the value; it's faster and will be
auto-freed at some point. This shortens the function and makes it
faster by not entering into a whole new shell context -- which
also fixes another problem: the error message from put_enum()
didn't cause the shell to exit for indexed enum arrays.
src/cmd/ksh93/sh/name.c: nv_setlist():
- Apply a patch from David Korn that correctly sets the data type
for associative arrays, fixing the ${array[@]} expansion yielding
random numbers. Thanks to @JohnoKing for the pointer.
https://github.com/ksh93/ksh/issues/87#issuecomment-662613887https://www.mail-archive.com/ast-developers@lists.research.att.com/msg00697.html
src/cmd/ksh93/tests/enum.sh:
- Add tests checking that invalid values are correctly blocked for
indexed and associative arrays of an enum type.
Makes progress on: https://github.com/ksh93/ksh/issues/87
This commit fixes 'command -x' to adapt to OS limitations with
regards to data alignment in the arguments list. A feature test is
added that detects if the OS aligns the argument on 32-bit or
64-bit boundaries or not at all, allowing 'command -x' to avoid
E2BIG errors while maximising efficiency.
Also, as of now, 'command -x' is a way to bypass built-ins and
run/query an external command. Built-ins do not limit the length of
their argument list, so '-x' never made sense to use for them. And
because '-x' hangs on Linux and macOS on every ksh93 release
version to date (see acf84e96), few use it, so there is little
reason not to make this change.
Finally, this fixes a longstanding bug that caused the minimum exit
status of 'command -x' to be 1 if a command with many arguments was
divided into several command invocations. This is done by replacing
broken flaggery with a new SH_XARG state flag bit.
src/cmd/ksh93/features/externs:
- Add new C feature test detecting byte alignment in args list.
The test writes a #define ARG_ALIGN_BYTES with the amount of
bytes the OS aligns arguments to, or zero for no alignment.
src/cmd/ksh93/include/defs.h:
- Add new SH_XARG state bit indicating 'command -x' is active.
src/cmd/ksh93/sh/path.c: path_xargs():
- Leave extra 2k in the args buffer instead of 1k, just to be sure;
some commands add large environment variables these days.
- Fix a bug in subtracting the length of existing arguments and
environment variables. 'size -= strlen(cp)-1;' subtracts one less
than the size of cp, which makes no sense; what is necessary is
to substract the length plus one to account for the terminating
zero byte, i.e.: 'size -= strlen(cp)+1'.
- Use the ARG_ALIGN_BYTES feature test result to match the OS's
data alignment requirements.
- path_spawn(): E2BIG: Change to checking SH_XARG state bit.
src/cmd/ksh93/bltins/whence.c: b_command():
- Allow combining -x with -p, -v and -V with the expected results
by setting P_FLAG to act like 'whence -p'. E.g., as of now,
command -xv printf
is equivalent to
whence -p printf
but note that 'whence' has no equivalent of 'command -pvx printf'
which searches $(getconf PATH) for a command.
- When -x will run a command, now set the new SH_XARG state flag.
src/cmd/ksh93/sh/xec.c: sh_exec():
- Change to using the new SH_XARG state bit.
- Skip the check for built-ins if SH_XARG is active, so that
'command -x' now always runs an external command.
src/lib/libcmd/date.c, src/lib/libcmd/uname.c:
- These path-bound builtins sometimes need to run the external
system command by the same name, but they did that by hardcoding
an unportable direct path. Now that 'command -x' runs an external
command, change this to using 'command -px' to guarantee using
the known-good external system utility in the default PATH.
- In date.c, fix the format string passed to 'command -px date'
when setting the date; it was only compatible with BSD systems.
Use the POSIX variant on non-BSD systems.
This commit resolves the following incorrect variable assignments:
$ unset a; typeset -uF a=2; typeset -p a
typeset -X a=0x1.0000000000p+1
$ unset a; typeset -Fu a=2; typeset -p a
typeset -X a=0x1.0000000000p+1
$ unset a; typeset -ulF a=2; typeset -p a
typeset -l -X a=0x1.0000000000p+1
$ unset a; typeset -Ful a=2; typeset -p a
typeset -l -X a=0x1.0000000000p+1
$ unset a; typeset -Eu a=2; typeset -p a
typeset -E -X a=2
$ unset a; typeset -Eul a=2; typeset -p a
typeset -l -E -X a=2
src/cmd/ksh93/bltins/typeset.c:
- If the unsigned option (-u) was provided in conjunction with a
floating point (-F) then due to a flag collision with NV_UNSIGN
and NV_HEXFLOAT both having the value of NV_LTOU caused the
floating point to become a hexadecimal floating point (-X) in
error. Also, if a -E option flag was followed with a -u option
then the resulting variable would be both a scientific notation
and a hexadecimal floating point at the same time.
src/cmd/ksh93/tests/attributes.sh:
- Add regression tests.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
An unquoted variable expansion evaluated in a DEBUG trap action
caused IFS field splitting to be deactivated in code executed after
the trap action. Thanks to Koichi Nakashima for the reproducer:
| v=''
| trap ': $v' DEBUG
| A="a b c"
| set -- $A
| printf '%s\n' "$@"
|
| Expected
|
| a
| b
| c
|
| Actual
|
| a b c
src/cmd/ksh93/sh/fault.c: sh_trap():
- Remove incorrect save/restore of sh.ifstable, the internal state
table for field splitting. This reverts three lines added in ksh
93t+ 2009-11-30. Analysis: As an expansion is split into fields
(macro.c, lines 2367-2471), sh.ifstable is modified. If that
happens within a DEBUG trap, any modifications in ifstable are
undone by the restoring memccpy, leaving an inconsistent state.
src/cmd/ksh93/COMPATIBILITY:
- Document the DEBUG trap fixes, particularly the incorrect
inheritance by subshells and functions that some scripts may now
rely on because this bug is so longstanding. (re: 2a835a2d)
src/cmd/ksh93/tests/basic.sh:
- Add relevant tests.
Resolves: https://github.com/ksh93/ksh/issues/155
TODO: add a -T (-o functrace) option as in bash, which should allow
subshells and ksh-style functions to inherit DEBUG traps.
P.S.: The very handy multishell repo allows us to use 'git blame'
to trace the origin of the recently fixed DEBUG trap bugs.
The off-by-one error causing various bugs, reverted in 2a835a2d,
was introduced in ksh 93t 2008-07-25:
https://github.com/multishell/ksh93/commit/8e947ccf
(fault.c, line 321)
The incorrect check causing the exit status bug, reverted in
d00b4b39, was introduced in ksh 93t 2008-11-04:
https://github.com/multishell/ksh93/commit/b1ade268
(fault.c, line 459)
The ifstable save/restore causing the field splitting bug, reverted
in this commit, was introduced in ksh 93t+ 2009-11-30:
https://github.com/multishell/ksh93/commit/53d9f009
(fault.c, lines 440, 444, 482)
So all the bugs reported in #155 were fixed by simply reverting
these specific changes. I think that they are some experiments that
the developers simply forgot to remove. I've suspected such a thing
multiple times before. ksh93 was developed by researchers who were
genius innovators, but incredibly sloppy maintainers.
Turns out the previous commit also fixed the bug that disables the
DEBUG trap if a redirection is used in a DEBUG trap action -- in
other words, that's the same bug.
src/cmd/ksh93/tests/basic.sh:
- Add test from the reproducer in the bug report.
Makes progress on: https://github.com/ksh93/ksh/issues/155
This trap failed to be restored correctly when being trapped in
a subshell, causing corruption or a crash when restoring the
parent shell environment's trap upon leaving the subshell.
Thanks to Koichi Nakashima for the report and reproducer.
src/cmd/ksh93/sh/fault.c: sh_sigreset():
- Fix an off-by-one error in the loop that restores the
pseudosignal traps.
src/cmd/ksh93/tests/basic.sh:
- Test overwriting the main shell trap in a subshell for all
pseudosignals.
Makes progress on: https://github.com/ksh93/ksh/issues/155
The build system is adapted to make SHOPT_* compile-time options
editable without nmake. We can now easily change ksh's compile-time
options by editing src/cmd/ksh93/SHOPT.sh. The bin/package script
is adapted to turn these into compile flags. This resolves the most
important drawback of not using nmake.
Also, mamake now has support for indented Mam (Make Abstract
Machine) code. Only one type of block (make...done) is supported in
Mamfiles, so they are easy to indent automatically. A script to
(re)do this is included.
Since nmake is not going to be restored (it has too many problems
that no one is interested in fixing), this at least makes mamake
significantly easier to work with.
The Makefiles are deleted. They may still be handy for reference to
understand the Mamfiles, but they haven't actually matched the
Mamfiles for a while -- and you can still look in the git history.
Deleting them requires some adaptations to bin/package and mamake.c
because, even though they do not use those files, they still looked
for them to decide whether to build code in a directory.
Finally, this commit incorporates some #pragmas for clang to
suppress annoying warnings about the coding style used in this
historic code base. (gcc does not complain so much.)
src/cmd/ksh93/SHOPT.sh:
- Added.
bin/package, src/cmd/INIT/package.sh:
- cd into our own directory in case we were run from another dir.
- $makefiles: only look for Mamfiles.
- Add ksh compile-options via KSH_SHOPTFLAGS. Include SHOPT.sh.
- make_recurse(): Do not write a missing Makefile.
- finalize environment: Look for Mamfiles instead of Makefiles.
src/cmd/INIT/mamake.c:
- Tell clang to suppress annoying warnings about coding style.
- Update version string and self-documentation.
- input(): Add support for indented Mam code by skipping initial
whitespace on each input line.
- files[]: Instead of looking for various of Makefiles to decide
where to build, only look for Mamfiles.
src/Makefile, src/cmd/INIT/Makefile, src/cmd/Makefile,
src/cmd/builtin/Makefile, src/cmd/ksh93/Makefile, src/lib/Makefile,
src/lib/libast/Makefile, src/lib/libcmd/Makefile,
src/lib/libdll/Makefile, src/lib/libsum/Makefile:
- Removed.
src/Mamfile, src/cmd/INIT/Mamfile, src/cmd/Mamfile,
src/cmd/builtin/Mamfile, src/cmd/ksh93/Mamfile, src/lib/Mamfile,
src/lib/libast/Mamfile, src/lib/libcmd/Mamfile,
src/lib/libdll/Mamfile, src/lib/libsum/Mamfile:
- Indent the code with tabs.
- In ksh93/Mamfile, add ${KSH_SHOPT_FLAGS} to every $CC command.
- In ksh93/Mamfile, add "prev SHOPT.sh" for every *.o file
so they are rebuilt whenever SHOPT.sh changes.
bin/Mamfile_indent:
- Added, in case someone wants to re-indent a Mamfile.
src/cmd/INIT/proto.c, src/cmd/INIT/ratz.c, src/cmd/INIT/release.c,
src/lib/libast/features/common, src/lib/libast/include/ast.h:
- Tell clang to suppress annoying warnings about coding style that
it disapproves of (mainly concerning the use of parentheses).
src/cmd/INIT/cc.darwin, src/cmd/INIT/cc.freebsd,
src/cmd/INIT/cc.openbsd:
- Remove now-redundant clang warning suppression flags.
Resolves: https://github.com/ksh93/ksh/issues/60
This adds informative error messages if incompatible options are
given. It also documents the exclusive -m, -n and -T options on
separate usage lines, as was already done with -f. The usage
message for incompatible options now looks something like this:
| $ ksh -c 'typeset -L10 -F -f -i foo'
| ksh: typeset: -i/-F/-E/-X cannot be used with -L/-R/-Z
| ksh: typeset: -f cannot be used with other options
| Usage: typeset [-bflmnprstuxACHS] [-a[type]] [-i[base]] [-E[n]]
| [-F[n]] [-L[n]] [-M[mapping]] [-R[n]] [-X[n]]
| [-h string] [-T[tname]] [-Z[n]] [name[=value]...]
| Or: typeset -f [name...]
| Or: typeset -m [name=name...]
| Or: typeset -n [name=name...]
| Or: typeset -T [tname[=(type definition)]...]
| Help: typeset [ --help | --man ] 2>&1
(see also the previous commit, e21a053e)
Unfortunately the first "Usage" line has some redundancies with the
"Or:" lines showing separate usages. It doesn't seem to be possible
to avoid this; it's a flaw in how libast generates everything
(usage, help, manual) from one huge getopt(3) string. I still think
the three added "Or:" lines are an improvement as it wasn't
previously shown that these options need to be used on their own.
src/cmd/ksh93/bltins/typeset.c: b_typeset():
- Instead of only showing a generic usage message, add an
informative error message if incompatible options were given.
- Conflicting options detection was failing because NV_LJUST and
NV_EXPNOTE have the same bitmask value. Use a new 'isadjust'
flag for -L/-R/-Z to remember if one of these was set.
- Detect conflict between -L/-R/-Z and a float option, not just -i.
src/cmd/ksh93/include/name.h, src/cmd/ksh93/data/msg.c:
- Add the two new error messages for incompatible options.
src/cmd/ksh93/data/builtins.c: sh_opttypeset[]:
- Add a space after 'float' in in "[+float?\btypeset -lE\b]" as
this makes 'float' appear on its own line, improving formatting.
- Show -m, -n, -T on separate usage lines like -f, as none of these
can be combined with other options.
- Remove "cannot be combined with other options" from -m and -n
descriptions, as that should now be clear from the separate usage
lines -- and even if not, the error message is now informative.
src/cmd/ksh93/sh.1, src/cmd/ksh93/COMPATIBILITY:
- Update.
src/cmd/ksh93/tests/types.sh:
- Remove obsolete test: 'typeset -RF' is no longer accepted.
(It crashed in 93u+, so this is not an incompatibility...)
Resolves: https://github.com/ksh93/ksh/issues/48
This fixes the following:
trap ':' DEBUG
r=$(exit 123)
echo $? # Expected 123, but actually 0.
Thanks to Koichi Nakashima for the report and reproducer.
src/cmd/ksh93/sh/fault.c: sh_trap():
- Restore the saved current exit status (exitval) for all traps.
Do not except the DEBUG trap from doing that. I've no idea why
this exception was made, but it's not correct.
src/cmd/ksh93/tests/basic.sh:
- Add tests.
Makes progress on: https://github.com/ksh93/ksh/issues/155
This commit also further mitigates the problems with restoring an
inaccessible or nonexistent PWD on exiting a virtual subshell.
Harald van Dijk writes:
> On a build of ksh with -fsanitize=undefined to help diagnose
> problems:
>
> $ mkdir deleted
> $ cd deleted
> $ rmdir ../deleted
> $ ksh -c '(cd /; (cd /)); :'
> /home/harald/ksh/src/cmd/ksh93/sh/subshell.c:561:22: runtime
> error: null pointer passed as argument 1, which is declared to
> never be null
> Segmentation fault (core dumped)
>
> Note that it segfaults the same with default compilation flags,
> but it does not print out the useful extra message. The code
> assumes that pwd is non-null and passes it to strcmp without
> checking, but it will be null if the current directory cannot be
> determined, for instance because it has been deleted.
src/cmd/ksh93/sh/subshell.c: sh_subshell():
- Avoid the null pointer dereference reported above.
src/cmd/ksh93/bltins/cd_pwd.c: b_cd():
- Fork a virtual subshell even on systems with fchdir(2) if the
present working directory tests as inaccessible on invoking 'cd';
it may no longer exist and fchdir would fail to get a handle.
(For the test we have to opendir(3) the full path to the PWD and
not ".", as the latter may succeed even if the PWD is gone.)
src/cmd/ksh93/data/builtins.c:
- Update 'cd' version string.
Fixes: https://github.com/ksh93/ksh/issues/153
Related: https://github.com/ksh93/ksh/issues/141
The forking fix implemented in 102868f8 and 9d428f8f, which stops
the main shell's hash table from being cleared if PATH is changed
in a subshell, can cause a significant performance penalty for
certain scripts that do something like
( PATH=... command foo )
in a subshell, especially if done repeatedly. This is because the
hash table is cleared (and hence a subshell forks) even for
temporary PATH assignments preceding commands.
It also just plain doesn't work. For instance:
$ hash -r; (ls) >/dev/null; hash
ls=/bin/ls
Simply running an external command in a subshell caches the path in
the hash table that is shared with a main shell. To remedy this, we
would have to fork the subshell before forking any external
command. And that would be an unacceptable performance regression.
Virtual subshells do not need to fork when changing PATH if they
get their own hash tables. This commit adds these. The code for
alias subshell trees (which was removed in ec888867 because they
were broken and unneeded) provided the beginning of a template for
their implementation.
src/cmd/ksh93/sh/subshell.c:
- struct subshell: Add strack pointer to subshell hash table.
- Add sh_subtracktree(): return pointer to subshell hash table.
- sh_subfuntree(): Refactor a bit for legibility.
- sh_subshell(): Add code for cleaning up subshell hash table.
src/cmd/ksh93/sh/name.c:
- nv_putval(): Remove code to fork a subshell upon resetting PATH.
- nv_rehash(): When in a subshell, invalidate a hash table entry
for a subshell by creating the subshell scope if needed, then
giving that entry the NV_NOALIAS attribute to invalidate it.
src/cmd/ksh93/sh/path.c: path_search():
- To set a tracked alias/hash table entry, use sh_subtracktree()
and pass the HASH_NOSCOPE flag to nv_search() so that any new
entries are added to the current subshell table (if any) and do
not influence any parent scopes.
src/cmd/ksh93/bltins/typeset.c: b_alias():
- b_alias(): For hash table entries, use sh_subtracktree() instead
of forking a subshell. Keep forking for normal aliases.
- setall(): To set a tracked alias/hash table entry, pass the
HASH_NOSCOPE flag to nv_search() so that any new entries are
added to the current subshell table (if any) and do not influence
any parent scopes.
src/cmd/ksh93/sh/init.c: put_restricted():
- Update code for clearing the hash table (when changing $PATH) to
use sh_subtracktree().
src/cmd/ksh93/bltins/cd_pwd.c:
- When invalidating path name bindings to relative paths, use the
subshell hash tree if applicable by calling sh_subtracktree().
- rehash(): Call nv_rehash() instead of _nv_unset()ting the hash
table entry; this is needed to work correctly in subshells.
src/cmd/ksh93/tests/leaks.sh:
- Add leak tests for various PATH-related operations in the main
shell and in a virtual subshell.
- Several pre-existing memory leaks are exposed by the new tests
(I've confirmed these in 93u+). The tests are disabled and marked
TODO for now, as these bugs have not yet been fixed.
src/cmd/ksh93/tests/subshell.sh:
- Update.
Resolves: https://github.com/ksh93/ksh/issues/66
The SHOPT_2DMATCH code block in sh_setmatch() modifies the 'ap'
pointer, which is initialised as nv_arrayptr(SH_MATCHNOD). This
caused a (rarely occurring) segfault in the following line near the
end of the function:
ap->nelem -= x;
as this line assumed that 'ap' still had the initial value.
src/cmd/ksh93/sh/init.c: sh_setmatch():
- On init, save ap in ap_save and use ap_save instead of ap where
it should be pointing to SH_MATCHNOD. This also allows removing
two redundant nv_arrayptr(SH_MATCHNOD) calls, slightly increasing
the efficiency of this function.
@stephane-chazelas writes:
> Per POSIX[*], cd should skip the $CDPATH processing if the first
> component of the directory given to cd is . or ...
>
> Yet, with ksh93u+m 2021-01-03 at least, while that's OK with ..,
> it's not with . with or without the posix option:
>
> $ CDPATH=/ ./ksh -o posix -c 'cd -P ./etc && pwd'
> /etc
> /etc
>
> It seems to be a regression introduced with ksh93u+ as I can't
> reproduce it with ksh93u or any version prior to that. I can also
> reproduce in u+, v- and the ksh2020 from the Ubuntu 20.04
> package.
src/cmd/ksh93/bltins/cd_pwd.c: b_cd():
- Skip $CDPATH processing not only if the path is absolute, but
also if the initial path component is '.' or '..' (in the latter
case the $CDPATH processing was done but appeared to be a no-op).
src/cmd/ksh93/tests/builtins.sh:
- Add regression test.
[*] https://pubs.opengroup.org/onlinepubs/9699919799.2018edition/utilities/cd.html
Fixes: https://github.com/ksh93/ksh/issues/151
When starting ksh +s, it gets stuck in an infinite loop continually
trying to parse its own binary as a shell script and rejecting it:
$ arch/linux.i386-64/bin/ksh +s
arch/linux.i386-64/bin/ksh: arch/linux.i386-64/bin/ksh: cannot execute [Exec format error]
arch/linux.i386-64/bin/ksh: arch/linux.i386-64/bin/ksh: cannot execute [Exec format error]
arch/linux.i386-64/bin/ksh: arch/linux.i386-64/bin/ksh: cannot execute [Exec format error]
arch/linux.i386-64/bin/ksh: arch/linux.i386-64/bin/ksh: cannot execute [Exec format error]
arch/linux.i386-64/bin/ksh: arch/linux.i386-64/bin/ksh: cannot execute [Exec format error]
[...]
$ echo 'echo "this is stdin"' | arch/linux.i386-64/bin/ksh +s
arch/linux.i386-64/bin/ksh: arch/linux.i386-64/bin/ksh: cannot execute [Exec format error]
(no loop, but still ksh trying to parse itself)
src/cmd/ksh93/sh/init.c: sh_init():
- When forcing on the '-s' option upon finding no command
arguments, also update sh.offoptions, a.k.a. shp->offoptions.
This avoids the inconsistent state causing this problem.
In main.c, there is:
if(sh_isoption(SH_SFLAG))
fdin = 0;
else
(code to open $0 as a file)
This was entering the else block because sh_isoption(SH_SFLAG)
was returning 0, and $0 is set to the ksh binary as it is
supposed to when no other script is provided. When I looked for
why sh_isoption was returning 0, I found main.c's
for(i=0; i<elementsof(shp->offoptions.v); i++)
shp->options.v[i] &= ~shp->offoptions.v[i];
Before this loop, shp->offoptions tracks which options were
explicitly disabled by the user on the command line. The effect
of this loop is to make "explicitly disabled" take precedence
over "implicitly enabled". My patch removes the registration of
the +s option.
Fixes: https://github.com/ksh93/ksh/issues/150
Co-authored-by: Martijn Dekker <martijn@inlv.org>
Issuing typeset floating point numerics having a precision of 0
failed as the precision/size was being overwritten with the string
length of the value, e.g. 'typeset -F0 x=5.67' would result in
'typeset -F 4 x=5.6700' as len('5.67') is 4.
src/cmd/ksh93/include/nval.h:
- Created a symbolic name of NV_FLTSIZEZERO to respresent a float
having a precision/size of 0. NV_FLTSIZEZERO needs to be a
negative value.
src/cmd/ksh93/bltins/typeset.c:
- In b_typeset(), added code to set tdata.argnum to NV_FLTSIZEZERO
for E, F, X options.
- In setall(), adjusted code to allow for tp->argnum to be negative.
src/cmd/ksh93/sh/name.c: nv_newattr():
- Adjusted option value only change code to handle NV_FLTSIZEZERO as
well as changed to directly setting np->nvsize instead of using
nv_setsize(np,size) as nv_setsize might contain conflicting and/or
redundant code.
- Added missing conditional check of '!(newatts&NV_INTEGER)' to
constrain the size==0 code block to justified strings as
NV_LJUST, NV_RJUST, or NV_ZFILL are only valid for strings if
NV_INTEGER is not set. This code block was mistakenly setting
the precision/size value to the length of the value of an
assignment for floats whereas it should only be performing
auto assignment length for justified strings.
'typeset -xu' and 'typeset -xl' would export the variable but fail
to change case in the value as the check between old and new
attributes did not provide the necesssary insight for lower or
upper case transcoding due to the lower or upper case attribute
being set within typeset.c prior to calling name.c nv_newattr
function.
Previous rhbz#1188377 patch added a conditional check for size==-1
which in effect caused the nv_newattr export code block return
optimization to never be executed as one cannot set any attributes
using the readonly builtin. By altering the size==-1 check to !trans
the export only optimization can run.
Also, the rhbz#1188377 patch altered new_attr function by setting
the new size to oldsize if run by the readonly builtin. The result
of setting size==oldsize allowed the succeeding if statement to
run more frequently and if size was a non-zero value resulted in
nv_setsize resetting the value to what it already was. Investigation
yielded that size was always 0 coming from the readonly builtin.
src/cmd/ksh93/bltins/typeset.c:
- Remove the setting of tdata.argnum to -1 as it is not needed due to
existing name.c nv_newattr() logic.
src/cmd/ksh93/sh/name.c: nv_newattr():
- Corrected the export only check optimization by using !trans instead
of using size==-1.
- Removed previous condition check to set size=oldsize if coming from
the readonly builtin. nv_newattr already had existing logic to
prevent changing the size via nv_setsize as size is always 0 when
coming from readonly builtin.
Virtual/non-forking subshells that change the present working
directory (PWD) with 'cd' suffer from a serious race condition. The
PWD is changed within the same process. This means it may not be
possible to change back to the original PWD when exiting the
subshell, as some other process may destroy the PWD or modify its
permissions in the meantime. ksh did not handle this error
condition at all, so, after exiting a subshell that invoked 'cd',
it could silently end up running the script's following command(s)
in the wrong directory. Which might be 'rm -rf *'. So, ouch.
The proper and obvious fix is never to allow a virtual subshell to
change the PWD, as it can never be guaranteed you can return to a
previous directory. If the PWD is changed in a child process, there
is no need to restore it in the parent process, and this whole
problem is avoided. So subshells really should always fork on
encountering a 'cd' command.
But forking is slow. It is not uncommon for scripts to 'cd' in a
subshell that is run repeatedly in a loop.
There is also the issue of custom builtins that can be added to ksh
via shared libraries. In the standard shell language, 'cd' is the
only command that changes the PWD, so we could just make that
command fork the subshell it is run from. But there's no telling
what a custom builtin might do.
So this commit implements a compromise that will not affect
performance unless there is the pathological condition of a PWD
that has been rendered inaccessible in some way:
1. When entering a virtual subshell, if the parent shell's PWD
proves inaccessible upon saving it, the subshell will now fork into
a separate process, avoiding the unrestorable PWD problem.
2. If some attack renders the parent shell's PWD unrestorable
*after* ksh enters a virtual subshell, ksh will now error out when
exiting it. There is nothing else left to do then. Continuing would
mean running arbitrary commands in the wrong PWD.
src/cmd/ksh93/sh/subshell.c:
- Put all the code/variables only needed for fchdir() behind '#if
_lib_fchdir'. This makes it clearer what's what.
(I don't know if there is still any system out there without
fchdir(3); I haven't found any. The chdir(3) fallback version may
be removed later as there is no way to make it remotely secure.)
- Fix the attempt to use the O_PATH mode for open(2) as a fallback
for nonexistent O_SEARCH on Linux. Define _GNU_SOURCE on Linux,
or <fcntl.h> (which is included indirectly) won't define O_PATH.
- Fix use of O_SEARCH. The code was simply wrong, repeating an
open(".",O_RDONLY) instead. Since a nonexistent O_SEARCH is now
redefined as either O_PATH or O_RDONLY, we can simply
open(".",O_SEARCH) and be done with it.
- Fix fatal error handling. Introduce fatal error condition for
failure to fchdir(3) back to the parent's PWD; rename 'duped' to
'fatalerror' and use it for error numbers; save and restore errno
on fatal error so the message will report the cause. (We must
call errormsg() near the end of sh_subshell() to avoid crashes.)
- If open(".",O_SEARCH) was not able get a file descriptor to our
PWD on entry, then call sh_subfork() immediately before running
the subshell commands. (Forking earlier causes a crash.)
- When restoring the PWD, if fchdir(3) fails, do *not* fall back to
chdir(3). We already know the PWD is inaccessible, so if chdir(3)
"succeeds" then, it's very likely to be a substitute injected by
an attacker.
src/cmd/ksh93/bltins/cd_pwd.c:
- If we don't have fchdir(3), then sh_subshell() must fall back to
chdir(2) to restore the PWD. That is highly vulnerable, as a
well-timed rename would allow an attacker to usurp the PWD. We
can't do anything about that if some custom builtin changes the
PWD, but we can at least make 'cd' always fork a subshell, which
slows down ksh but removes the need for the parent shell ever to
restore the PWD. (There is certainly no popular system where this
is relevant and there might not be any such current system.)
This commit adds no regression test because a portable regression
test is not really doable. Different kernels, external /bin/pwd
utilities, etc. all have quite different behaviour under the
pathological condition of an inaccessible PWD, so both the
before-fix and the after-fix behaviour differs. See link below.
Resolves: https://github.com/ksh93/ksh/issues/141
Thanks to Stéphane Chazelas for the bug report.
Autoloading a function caused the calling script's $LINENO to be
off by the number of lines in the function definition file. In
addition, while running autoloaded functions, errors/warnings were
reported with wrong line numbers.
src/cmd/ksh93/sh/path.c:
- Save $LINENO (shp->inlineno) before autoloading a function, reset
it to 1 so that the correct line number offset is remembered for
the function definition, and restore it after.
src/cmd/ksh93/tests/variables.sh:
- Add regression test for $LINENO, directly and in error messages,
within and outside a non-autoloaded and an autoloaded function.
Fixes: https://github.com/ksh93/ksh/issues/116
ksh 93u+ introduced a regression in the combination of the
'set -o pipefail' and 'set -e'/'set -o errexit' options:
$ ksh93 -o errexit -o pipefail -c \
'(exit 3) | true; echo "still here despite $? status"'
still here despite 3 status
The bug is in how the the huge sh_exec() function in xec.c handles
the 'echeck' flag. Near the end of sh_exec(), this flag triggers a
sh_chktrap() call to check whether to trigger any traps, including
the ERR trap -- and that same function also handles the errexit
option, which is basically the same as 'trap "exit" ERR'.
We can learn more easily how sh_exec() works by inserting debug
warnings in all its 'switch(type&COMMSK)' cases, like:
case TCOM:
errormsg(SH_DICT,ERROR_warn(0),"[DEBUG] TCOM");
... and same for all the others. With that done, the output
of a very simple dummy pipeline looks as follows:
$ arch/*/bin/ksh -c 'true | true | true'
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TFIL
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TFORK
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TFORK
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TSETIO
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TCOM
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TCOM
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TCOM
So, it looks like sh_exec() handles this pipeline as follows:
TFIL
|_____TFORK
| |_____TCOM
|_____TFORK
| |_____TCOM
|_____TSETIO
|_____TCOM
Each time a pipeline like command1 | command2 | ... is executed,
sh_exec() is invoked with type TFIL; this then recursively invokes
sh_exec() to handle the individual elements. The last element of
the pipe triggers a sh_exec() run with type TSETIO; since it is run
in the current shell environment, it is effectively treated as a
command with an input redirection. All the previous elements are of
type TFORK instead, because they are executed asynchronously in
separate, forked subshell processes. Finally, the TFORK or TSETIO
code then recursively calls sh_exec() again with type TCOM to
actually execute the commands.
When reading the code, we find that the 'echeck' flag is set as
part of the TSETIO code. This makes sense of why only an error in
the last element of the pipe triggers the errexit/ERR trap action.
So that's the bug: the flag is set in the wrong place.
This can be fixed by setting that flag in the TFIL handling code
instead, as this is what calls everything else and collects all the
exit statuses. So the sh_chktrap() call is now executed after
handling the entire pipeline, at the TFIL recursion level.
This also allows getting rid of the special-casing in the buggy
TSETIO version. The SH_ERREXIT state is restored at the end of each
sh_exec() call, so since we're now doing this at a lower recursion
level, it will already have been restored.
src/cmd/ksh93/sh/xec.c: sh_exec():
- Fix the bug as per the above.
src/cmd/ksh93/tests/options.sh:
- Add tests for errexit and ERR trap combined with pipefail.
src/cmd/ksh93/tests/basic.sh:
- Tweak a couple of tests that reported a trap wasn't triggered
even if it was actually triggered more than once.
Fixes: https://github.com/ksh93/ksh/issues/121
Thanks to Stéphane Chazelas for the bug report.
'typeset -xu' and 'typeset -xl' would export the variable but fail
to change case in the value under certain conditions.
Original patch:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-xufix.patch
This applies the patch essentially without change and adds a
regression test based on the reproducer provided in the RH bug.
Unfortunately there is no description of how the patch works and
it's a little obscure to me. As far as I can figure out, the cause
of the problem was that nv_newattr() erroneously processed a
nonexistent size option-argument such as what can be given to
options like typeset -F, e.g. typeset -F3 for 3 digits after the
dot. A nonexistent size argument is represented by the value of -1.
Prior discussion:
https://bugzilla.redhat.com/1454804
On 2017-05-23 13:33:25 UTC, Paulo Andrade wrote:
> In previous ksh versions, when exiting the scope of a ksh
> (not posix) function, it would restore the trap table of
> the "calling context" and if the reason the function exited
> was a signal, it would call sh_fault() passing as argument
> the signal value.
> Newer ksh checks it, but calls kill(getpid(), signal_number)
> after restoring the trap table, but only calls for SIGINT and
> SIGQUIT.
[...]
> The old way appears to have been more appropriate, but there
> must be a reason to only pass SIGINT and SIGQUIT as it is an
> explicit patch.
The last paragraph is where I differ. This would not be the first
example of outright breakage that appeared to be added deliberately
and that 93u+m has fixed or removed, see e.g. 8477d2ce ('printf %H'
had code that deleted all multibyte characters), cefe087d, or
781f0a39. Sometimes it seems the developers added a little
experiment and then forgot all about it, so it became a misfeature.
In this instance, the correct pre-2012 ksh behaviour is still
explicitly documented in (k)sh.1: "A trap condition that is not
caught or ignored by the function causes the function to terminate
and the condition to be passed on to the caller". Meaning, if there
is no function-local trap, the signal defaults to the parent scope.
There is no language that limits this to SIGINT and SIGQUIT only.
It also makes no sense at all to do so -- signals such as SIGPIPE,
SIGTERM, or SIGSEGV need to be caught by default and to do
otherwise results in misbehaviour by default.
src/cmd/ksh93/sh/xec.c: sh_funscope():
- When resending a signal after restoring the global traps state,
remove the spurious check that limits this to SIGINT and SIGQUIT.
- Replace it with a check for nsig!=0, as that means there were
parent trap states to restore. Otherwise 'kill' may be called
with an invalid signal argument, causing a crash on macOS.
src/cmd/ksh93/tests/signal.sh:
- Update a test to check that a function-local SIGTERM trap is
triggered correctly when signalled from another process.
- Complete the tests for 3aee10d7; this bug needed fixing before
we could test that previous fix in a ksh function scope.
- Add a test for triggering global traps from ksh functions,
testing multiple POSIX-standard signals.
This imports a new version of the code to import environment
variable values that was sent to Red Hat from upstream in 2014.
It avoids importing environment variables whose names are not valid
in the shell language, as it would be impossible to change or unset
them. However, they stay in the environment to be passed to child
processes.
Prior discussion: https://bugzilla.redhat.com/1147645
Original patch: https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-oldenvinit.patch
src/cmd/ksh93/sh/init.c:
- env_init(): Import new, simplified code to import environment
variable name/value pairs. Instead of doing the heavy lifting
itself, this version uses nv_open(), passing the NV_IDENT flag to
reject and skip invalid names.
- Get rid of gotos and a static var by splitting off the code to
import attributes into a new env_import_attributes() function.
This is a better way to avoid importing attributes when
initialising the shell in POSIX mode (re: 00d43960
- Remove an nv_mapchar() call that was based on some unclear
flaggery which was also removed by upstream as sent to Red Hat.
I don't know what that did, if anything; looks like it might have
had something to do with typeset -u/-l, but those particular
attributes have never been successfully inherited through the
environment.
(Maybe that's another bug, or maybe I just don't care as
inheriting attributes is a misfeature anyway; we have to put up
with it because legacy scripts might use it. Maybe someone can
prove it's an unacceptable security risk to import attributes
like readonly from an environment variable that is inherently
vulnerable to manipulation. That would be nice, as a CVE ID
would give us a solid reason to get rid of this nonsense.)
- Remove an 'else cp += 2;' that was very clearly a no-op; 'cp' is
immediately overwritten on the next loop iteration and not used
past the loop.
src/cmd/ksh93/tests/variables.sh:
- Test.
According to 'whence --man', 'whence -f' should ignore functions:
-f Do not check for functions.
Right now this is only accomplished partially. As of commit
a329c22d 'whence -f' avoids any output when encountering a
function (in ksh93u+ 'whence -f' has incorrect output). The
return value is still wrong though:
$ foo() { true; }
$ whence -f foo; echo $?
0
This commit fixes the return value and makes 'type -f' error out
when given a function (like in Bash).
src/cmd/ksh93/bltins/whence.c:
- If -f was passed, set 'cp' to NULL since functions should be
ignored (as documented).
- Simplify return value by avoiding bitwise logic.
src/cmd/ksh93/tests/builtins.sh:
- Add regression tests for 'whence -f' and 'type -f'.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
Since at least 1999, whence -v on pdksh (and its successor mksh)
reports the path where an autoloadable function may be found:
$ mkdir ~/fun; FPATH=~/fun
$ echo 'myfn() { echo hi; }' >~/fun/myfn
$ whence -v myfn
myfn is a undefined (autoload from /home/user/fun/myfn) function
Whereas ksh93 only reports, rather uselessly:
myfn is an undefined function
As of this commit, whence -v/-a on ksh 93u+m does the same as
pdksh, but with correct grammar:
myfn is an undefined function (autoload from /home/user/fun/myfn)
This may be a small violation of my own "no new features" policy
for 93u+m, but I couldn't resist. This omission has been annoying
me, and it's just embarrassing to lack a pdksh feature :)
src/cmd/ksh93/include/path.h,
src/cmd/ksh93/data/msg.c:
- Add e_autoloadfrom[] = " (autoload from %s)" message.
src/cmd/ksh93/bltins/whence.c: whence():
- Report the path (if any) when reporting an undefined function.
This needs to be done in two places:
1. When a function has been explicitly marked undefined with
'autoload', we need to do a quick path_search() loop to find
the path. (These undefined functions take precedence over
regular commands, so are reported first.)
2. When a function is not explicitly autoloaded but merely
available in $FPATH, that path search was already done, so all
we need to do is report it. (These are reported last.)
Note that the output remains as on 93u+ if no function definition
file is found on $FPATH. This is also like pdksh/mksh.
src/cmd/ksh93/data/builtins.c:
- Bump 'whence' version date. The inline docs never detailed very
exactly what 'whence -v' reports, so no need for further edits.
src/cmd/ksh93/tests/path.sh:
- Regress-test the new whence behaviour plus actual autoloading,
including the command override behaviour of autoloaded functions.
The fixargs() function is invoked when ksh needs to run a script
without a #!/hashbang/path. Instead of letting the kernel invoke a
shell, ksh exfile()s the script itself from sh_main(). In the
forked child, it calls fixargs() to set the argument list in the
environment to the args of the new script, so that 'ps' and
/proc/PID/cmdline show the expected output.
But fixargs() is broken because, on systems other than HP-UX (on
which ksh uses pstat(2)), ksh simply inserts a terminating zero.
The arguments list is not a zero-terminated C string. Unix systems
expect the entire arguments buffer to be zeroed out, otherwise 'ps'
and /proc/*/cmdline will have fragments of previous command lines
in the output.
The Red Hat patch for this bug is:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-argvfix.patch
However, that fix is incomplete because 'command_len' was also
hardcoded to be limited to 64 characters (!), which still gave
invalid 'ps' output if the erased command line was longer.
src/cmd/ksh93/sh/main.c: fixargs():
- Remove CMD_LENGTH macro which was defined as 64.
- Remove code that limited the erasure of the arguments buffer to
CMD_LENGTH characters. That code also had quite a dodgy strdup()
call -- it copies arguments to the heap, but they are never freed
(or even used), so it's a memory leak. Also, none of this is
ever done if the length is calculated using pstat(2) on HP-UX,
which is a clear indication that it's unnecessary.
(I think this code block must have been some experiment they
forgot to remove. One reason why I think so is that a 64 byte
arguments limit never made sense, even in the 1980s when they
wrote ksh on 80-column CRT displays. Another indication of this
is that fixing it didn't require adding anything; the code to do
the right thing was already there, it was just being overridden.)
- Zero out the full arguments length as in the Red Hat patch.
src/cmd/ksh93/tests/basic.sh:
- Add test. It's sort of involved because 'ps' is one of the least
portable commands in practice, in spite of standardisation.
There was no check for the -B/braceexpand option before calling
path_expand() to process brace expansion, making it impossible to
turn off brace expansion within command substitutions. Normally the
lexer flags brace expansion so that this code is not reached, but
shell code within command substitutions is handled differently.
Red Hat patches this by adding this check to the function itself:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20140301-fikspand.patch
But I think it's more logical to patch it at the point of decision.
src/cmd/ksh93/sh/macro.c: endfield():
- Decide to call either path_generate() or path_expand() based on
the state of the SH_BRACEEXPAND shell option.
- Fix '#if SHOPT_BRACEPAT' preprocessor check that previously
hardcoded this decision at compile time.
src/cmd/ksh93/tests/options.sh:
- Add tests.
When using typeset -l or -u on a variable that cannot be changed
when the shell is in restricted mode, ksh crashed.
This fixed is inspired by this Red Hat fix, which is incomplete:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-tpstl.patch
The crash was caused by the nv_shell() function. It walks though a
discipline function tree to get the pointer to the interpreter
associated with it. Evidently, the problem is that some pointer in
that walk is not set correctly for all special variables.
Thing is, ksh only has one shell language interpreter, and only one
global data structure (called 'sh') to keep its main state[*]. Yet,
the code is full of 'shp' pointers to that structure. Most (not
all) functions pass that pointer around to each other, accessing
that struct indirectly, ostensibly to account for the non-existent
possibility that there might be more than one interpreter state.
The "why" of that is an interesting cause for speculation that I
may get to sometime. For now, it is enough to know that, in the
code as it is, it matters not one iota what pointer to the shell
interpreter state is used; they all point to the same thing (unless
it's broken, as in this bug).
So, rather than fixing nv_shell() and/or associated pointer
assignments, this commit simply removes it, and replaces it with
calls to sh_getinterp(), which always returns a pointer to sh (see
init.c, where that function is defined as literally 'return &sh').
[*] Defined in shell.h, with the _SH_PRIVATE part in defs.h
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/sh/name.c:
- Remove nv_shell().
src/cmd/ksh93/sh/init.c:
- In all the discipline functions for special variables, initialise
shp using sh_getinterp() instead of nv_shell().
src/cmd/ksh93/tests/variables.sh:
- Add regression test for typeset -l/-u on all special variables.
This imports another fix from Red Hat/Fedora. Original patch:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-crash.patch
src/cmd/ksh93/include/jobs.h,
src/cmd/ksh93/sh/jobs.c,
src/cmd/ksh93/sh/subshell.c,
src/cmd/ksh93/sh/xec.c:
- Import the Red Hat fix with these differences:
- Rename the 'hack1_waitall' variable to 'bktick_waitall' and add
a comment describing what it's for.
- Remove unused 'pipefail' variable.
src/cmd/ksh93/tests/basic.sh:
- Regression test from reproducer given in the Red Hat bug report.
- Add special handling to SIGKILL it, as it might freeze hard.
var=$(< file) now reads the file even if the standard inout,
standard output and/or standard error file descriptors are closed.
Original patch:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-filecomsubst.patch
src/cmd/ksh93/sh/io.c: sh_redirect():
- When processing the '<' redirector as part of $(< ...), i.e. if
flag==3, make sure the FD of the file to read is > 2 by calling
sh_iomovefd(). Unlike the RedHat patch, this checks for flag==3
to avoid unnecessary sh_iomovefd() calls for normal redirections,
as there was no bug with those.
src/cmd/ksh93/tests/io.sh:
- Add test.
Hopefully this doesn't introduce new bugs, but it does fix at
least the following:
1. When whence -v/-a found an "undefined" (i.e. autoloadable)
function in $FPATH, it actually loaded the function as a side
effect of reporting on its existence (!). Now it only reports.
2. 'whence' will now canonicalise paths properly. Examples:
$ whence ///usr/lib/../bin//./env
/usr/bin/env
$ (cd /; whence -v dev/../usr/bin//./env)
dev/../usr/bin//./env is /usr/bin/env
3. 'whence' no longer prefixes a spurious double slash when doing
something like 'cd / && whence bin/echo'. On Cygwin, an initial
double slash denotes a network server, so this was not just a
cosmetic problem.
4. 'whence -a' now reports a "tracked alias" (a.k.a. hash table
entry, i.e. cached $PATH search) even if an actual alias by the
same name exists. This needed fixing because in fact the hash
table entry continues to be used when bypassing the alias.
Aliases and "tracked aliases" are not remotely the same thing;
confusing nomenclature is not a reason to report wrong results.
5. When using 'hash' or 'alias -t' on a command that is also a
builtin to force caching a $PATH search for the external
command, 'whence -a' double-reported the path:
$ hash printf; whence -a printf
printf is a shell builtin
printf is /usr/bin/printf
printf is a tracked alias for /usr/bin/printf
This is now fixed so that the second output line is gone.
Plus, if there were multiple versions of the command on $PATH,
the tracked alias was reported at the end, which is the wrong
order. This is also fixed.
src/cmd/ksh93/bltins/whence.c: whence():
- Refactor the do...while loop that handles whence -v/-a for path
searches in such a way that the code actually makes sense and
stops looking like higher esotericism. Just doing this fixed#2,
#4 and #5 above (the latter two before I even noticed them). For
instance, the path_fullname() call to canonicalise paths was
already there; it was just never used.
- Remove broken 'notrack' flaggery for deciding whether to report a
hash table entry a.k.a. "tracked alias"; instead, check the hash
table (shp->track_tree).
src/cmd/ksh93/sh/path.c:
- path_search(): Re #3: When prefixing the PWD, first check if
we're in '/' and if so, don't prefix it; otherwise, adding the
next slash causes an initial double slash. (Since '/' is the only
valid single-character absolute path, all we need to do is check
if the second character pwd[1] is non-null.)
- path_search(): Re #1: Stop autoloading when called by 'whence':
* The 'flag==2' check to avoid autoloading a function was
broken. The flag value is 2 on the first whence() loop
iteration, but 3 on subsequent ones. Change to 'flag >= 2'.
* However, this only fixes it if the function file does not have
the x permission bit, as executable files are handled by
path_absolute() which unconditionally autoloads functions!
So, pass on our flag parameter when callling path_absolute().
- path_absolute(): Re #1: Add flag parameter. Do not autoload
functions if flag >= 2.
src/cmd/ksh93/include/path.h,
src/cmd/ksh93/bltins/typeset.c,
src/cmd/ksh93/sh/main.c,
src/cmd/ksh93/sh/xec.c:
- Re #1: Update path_absolute() calls, adding a 0 flag parameter.
src/cmd/ksh93/include/name.h:
- Remove now-unused pathcomp member from union Value. It was
introduced in 99065353 to allow examining the value of a tracked
alias. This commit uses nv_getval() instead.
src/cmd/ksh93/tests/builtins.sh,
src/cmd/ksh93/tests/path.sh:
- Add and tweak various related tests.
Fixes: https://github.com/ksh93/ksh/issues/84
{Brace,expansion} is potentially incompatible with POSIX scripts,
because in POSIX those are simple literal strings with no special
meaning. So the POSIX option should really turn that off.
As of b301d417, the 'posix' option was also forcing 'letoctal'
behaviour on, without actually setting that option. I've since
found that to be a botch; 'let' may recognise octals without that
option being set, and that looks like a bug.
So as of this commit, the '-o posix' option actually toggles both
of these options off/on and on/of, respectively. 'set +o posix'
toggles them inversely. However, it is now possible to control both
options (and their associated behaviour) independently in between
'set -o posix' and 'set +o posix'. Much better.
src/cmd/ksh93/sh/main.c: sh_main():
- If SH_POSIX was set on init, turn on SH_LETOCTAL by default
instead of SH_BRACEEXPAND.
src/cmd/ksh93/sh/args.c: sh_applyopts():
- Turn off SH_BRACEEXPAND and turn on SH_LETOCTAL when SH_POSIX is
turned on (but not if it was already on).
- Turn on SH_BRACEEXPAND and turn off SH_LETOCTAL when SH_POSIX is
turned off (but not if it was already off).
src/cmd/ksh93/sh/arith.c: arith():
- Revert to pre-b301d417 and only check SH_LETOCTAL option when
deciding whether 'let' should skip initial zeros.
src/cmd/ksh93/tests/options.sh:
- Update $- test to allow '-o posix' to switch B = braceexpand.
src/cmd/ksh93/sh.1:
- Update.
- Edit for clarity.
This patch from Red Hat fixes the following:
1. ksh was ignoring the -m (-o monitor) option when specified on
the invocation command line.
2. Scripts did not properly terminate their background processes
on Ctrl+C if the -m option was turned off. Reproducer:
xterm &
read junk
When run as a script without turning on -m, pressing Ctrl+C
should terminate the xterm, and now does.
3. Scripts no longer attempt to set the terminal foreground process
group ID, as only interactive shells should be doing that.
This makes some progress on https://github.com/ksh93/ksh/issues/119
but we're a long way from fixing all of that.
src/cmd/ksh93/sh/main.c: exfile():
- On non-interactive shells, do not turn off the monitor option.
Instead, if it was turned on, turn on the SH_MONITOR state flag.
src/cmd/ksh93/edit/edit.c: ed_getchar():
- On Ctrl+C, issue SIGINT to the current process group using
killpg(2) instead of going via sh_fault(), which handles a
signal only for the current shell process.
src/cmd/ksh93/sh/jobs.c: job_reap(), job_reset(),
src/cmd/ksh93/sh/xec.c: sh_exec():
- Only attempt to set the terminal foreground process group ID
using tcsetpgrp(3) if the shell is interactive.
Original patch: https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-kshmfix.patch
This was applied to Red Hat's ksh 93u+ on 8 July 2013.
src/cmd/ksh93/data/signals.c includes two checks for the JOBS
identifier; if it is not defined then the interactive shell's
background job signal messages for SIGINT and SIGPIPE are empty.
The cause was that the "jobs.h" header, which defines that ID, was
not #included in signals.c. This commit adds that #include.
(ksh 93u+, ksh 93v- and ksh2020 all have this bug as well.)
Before:
$ sleep 30 &
[1] 86430
$ kill -s INT "$!"
[1] + sleep 30 &
$
After:
$ sleep 30 &
[1] 86445
$ kill -s INT "$!"
[1] + Interrupt sleep 30 &
$
In the vi and emacs line editors, repeat count parameters can now
also be used for the arrow keys and the forward-delete key. E.g.,
in emacs mode, <ESC> 7 <left-arrow> will now move the cursor seven
positions to the left. In vi control mode, this would be entered
as: 7 <left-arrow>.
src/cmd/ksh93/edit/emacs.c:
- ed_emacsread(): Upon getting ^[ (ESC), save current repeat count
in a new variable; restore and reset it upon the next character.
- escape(): Minor bugfix: when processing a ^[[x sequence where 'x'
is a character other than '~' (which would be DEL), also reinsert
the final character into the buffer so scripts can detect them.
src/cmd/ksh93/edit/vi.c:
- cntlmode(): Do not reset the repeat count if the command is '[',
the character following ESC in VT220 escape sequences.
- mvcursor():
* Do not use getcount() to get the character following '[', as
that was parsing repetition parameters in the wrong place.
There wouldn't be any, so this would reset the repeat count.
* After that, no more need for the special-casing of ^[[3~ (DEL)
introduced in f2a3f4e3. Move it to within the 'switch' block.
* When handling left and right arrows and Home and End keys, do
not modify cursor directly but ed_ungetchar() the corresponding
traditional command keys as with the rest. Otherwise a repeat
count parameter would now wrongly survive those keys.
src/cmd/ksh93/sh.1:
- Document control character notation used for vi mode docs.
- Since vi control mode beeps and aborts on ESC except if a
subsequent [ is already in the input buffer upon receiving ESC,
document that VT220 escape sequences only preserve repeat counts
when entered into the input buffer all at once.
- Don't skip the initial ESC in the documentation of the VT220
escape sequences. In control mode, skipping the initial ESC still
works as before, but that is now undocumented, as it's really
nothing more than an artefact of VT220 escape processing.
- Move the two long paragraphs on '-o viraw' and canonical (i.e.
line-based) input processing from the vi editor introduction to
the options section under 'viraw'. It is much too arcane for the
intro, and besides, ksh 93u+ (and hence also 93u+m) has
SHOPT_VIRAW enabled by default, so the shell is compiled to force
this option on at all times, making it even less relevant for
most users.
On every modern system, the forward-delete key on PC/Mac keyboards
generates the VT220 sequence ESC [ 3 ~. Every other shell with an
editor handles this now, ksh93 seems to be the last not to.
src/cmd/ksh93/edit/emacs.c: escape():
- Handle the ^[[3 as part of normal escape processing, then read an
extra character to check for the final '~'. If detected, insert
an ERASECHAR key event.
src/cmd/ksh93/edit/vi.c: mvcursor():
- Replace the ^[[3~ sequence by an 'x' command. We have to
special-case its processing, because vi mode parses numbers as
repetition operators. The escape sequence contains a number,
making it incompatible with normal command handling. This means
number repetitions don't work with the forward-delete key. If
that annoys anyone enough to fix it, a patch would be welcome.
For now, it will do to make the forward-delete key stop
exhibiting bizarre behaviour (beep + change case + move forward).
src/cmd/ksh93/sh.1
- Copy-edit emacs documentation for VT220-style sequences; map them
to their actual key, otherwise it's meaningless to the reader.
- Document the new forward-delete key behaviour for emacs mode.
- Leave the forward-delete key for vi mode undocumented for now, as
repetitions don't work, so it doesn't really match the vi canon.
(OTOH, it doesn't work in vim, either...)
_sfcvt(), "convert a floating point value to ASCII", did not adjust
for negative decimal place movement as what happens with leading
zeroes. This caused ksh's 'printf %f' formatter to fail to round
floating point values correctly.
src/lib/libast/sfio/sfcvt.c:
- Removed constraint of <1e-8 for doubles by matching what was done
for long doubles having <.1.
- Corrected a condition when the next power of 10 occurred and that
new 1 digit was being overwritten by a 0.
src/cmd/ksh93/tests/math.sh:
- Validate that typeset -E/F formatting matches that of their
equivalent printf formatting options as well as checking for
correct float scaling of the fractional parts.
Following a community discussion, it became clear that 'r' is
particularly problematic as a regular builtin, as the name can and
does conflict with at least one legit external command by that
name. There was a consensus against removing it altogether and
letting users set the alias in their login scripts. However,
aliases are easier to bypass, remove or rename than builtins are.
My compromise is to reinstate 'r' as a preset alias on interactive
shells only, along with 'history', as was done in 17f81ebe before
they were converted to builtins in 03224ae3. So this reintroduces
the notion of predefined aliases to ksh 93u+m, but only for
interactive shells that are not initialised in POSIX mode.
src/cmd/ksh93/Makefile,
src/cmd/ksh93/Mamfile,
src/cmd/ksh93/include/shtable.h,
src/cmd/ksh93/data/aliases.c:
- Restore aliases.c containing shtab_aliases[], a table specifying
the preset aliases.
src/cmd/ksh93/include/shtable.h,
src/cmd/ksh93/sh/init.c:
- Rename inittree() to sh_inittree() and make it extern, because we
need to use it in main.c (sh_main()).
src/cmd/ksh93/sh/main.c: sh_main():
- Init preset aliases from shtab_aliases[] only if the shell is
interactive and not in POSIX mode.
src/cmd/ksh93/bltins/typeset.c,
src/cmd/ksh93/tests/alias.sh:
- unall(): When unsetting an alias, pass on the NV_NOFREE attribute
to nv_delete() to avoid an erroneous attempt to free a preset
alias from read-only memory. See: 5d50f825
src/cmd/ksh93/data/builtins.c:
- Remove "history" and "r" entries from shtab_builtins[].
- Revert changes to inline fc/hist docs in sh_opthist[].
src/cmd/ksh93/bltins/hist.c: b_hist():
- Remove handling for 'history' and 'r' as builtins.
src/cmd/ksh93/sh.1:
- Update accordingly.
Resolves: https://github.com/ksh93/ksh/issues/125
The 'command' name can now result from an expansion, e.g.:
c=command; "$c" ls
set -- command ls; "$@"
both work now. This fixes BUG_CMDEXPAN.
If -o posix is on, 'command' now disables not only the "special"
but also the "declaration" properties of builtin commands that it
invokes. This is because POSIX specifies 'command' as a simple
regular builtin, and any command name following 'command' is just
an argument to the 'command' command, so there is nothing that
allows any further arguments (such as assignment-arguments) to be
treated specially by the parser. So, if and only if -o posix is on:
a. Arguments that start with a variable name followed by '=' are
always treated as regular words subject to normal shell syntax.
b. Since assignment-arguments are not processed as assignments
before the command itself, 'command' can now stop the shell from
exiting (as required by the standard) if a command that it
invokes (such as 'export') tries to modify a readonly variable.
This fixes BUG_CMDSPEXIT.
Most of 'command' is integrated in the parser and parse tree
executer, so that is where it needed fixing.
src/cmd/ksh93/sh/parse.c: simple():
- If the posix option is on, do not skip past SYSCOMMAND so that
any declaration builtin commands that are arguments to 'command'
are not detected and thus not treated specially at parsetime.
src/cmd/ksh93/sh/xec.c: sh_exec():
- When detecting SYSCOMMAND in order to skip past it, not only
compare the Namval_t pointer 'np' to SYSCOMMAND, but also handle
the case where that pointer is NULL, as when the command name
results from an expansion. In that case, search the function tree
shp->fun_tree for the name and see if that yields the SYSCOMMAND
pointer. fun_tree is initialised with a dtview to bltin_tree, so
searching fun_tree instead allows for overriding 'command' with a
shell function (which the POSIX standard requires us to allow).
src/cmd/ksh93/sh.1,
src/cmd/ksh93/data/builtins.c:
- Update documentation to match these changes.
- Various related edits and improvements.
src/cmd/ksh93/tests/builtins.sh:
- Check that 'command' works if resulting from an expansion.
- Check that 'command' can be overridden by a shell function.
The 'exit' and 'return' commands without an argument failed to pass
down the exit status of the last-run command when incorporated in a
block with redirection, &&/|| list, 'case' statement, or 'while',
'until' or 'for' loop.
src/cmd/ksh93/bltins/cflow.c:
- Use $?, which is sh.savexit a.k.a. shp->savexit, as the default
exit status value if there is no argument, instead of
shp->oldexit. This fixes the default exit status behaviour to
match POSIX and other shells.
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/include/shell.h:
- Remove now-unused sh.oldexit (a.k.a. shp->oldexit) private struct
member. It appeared to fulfill the same function as sh.savexit,
but in a slightly broken way.
- Move the savexit/$? declaration from the _SH_PRIVATE part of the
struct definition to the public API part. Since $? uses this,
it's clearly a publicly exposed value already, and this is
generally the one to use. (If anything, it's exitval that should
have been private.) This declares savexit right next to exitval,
rewriting the comments to clarify the difference between them.
src/cmd/ksh93/sh/fault.c,
src/cmd/ksh93/sh/subshell.c,
src/cmd/ksh93/sh/xec.c:
- Remove assignments to shp->oldexit.
src/cmd/ksh93/tests/basic.sh:
- Add thorough regression tests for the default exit status
behaviour of 'return' and 'exit' in various lexical contexts.
- Verify that 'for' and 'case' without any command, as well as a
lone redirection, still correctly reset the exit status to 0.
Fixes: #117
${var:-wor)d} or ${var+w(ord}. The parentheses now correctly lose
their normal grammatical meaning within the braces. Fix by Eric
Scrivner (@etscrivner) from July 2018 backported from ksh2020.
This fix complies with POSIX:
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_02
src/cmd/ksh93/sh/lex.c: sh_lex():
- Set the ST_QUOTE state when analysing a modifier with parameter
expansions using operators ':', '-', '+', '='. This state causes
subsequent characters (including parentheses) to be considered
quoted, suppressing their normal grammatical meaning.
src/cmd/ksh93/sh/macro.c: varsub():
- Same for skipping the expansion.
Fixes: https://github.com/ksh93/ksh/issues/126
Prior discussion: https://github.com/att/ast/issues/475
When exporting variables, ksh exports their attributes (such as
'integer' or 'readonly') in a magic environment variable called
"A__z" (string defined in e_envmarker[] in data/msg.c). Child
shells recognise that variable and restore the attributes.
This little-known feature is risky; the environment cannot
necessarily be trusted and that A__z variable is easy to manipulate
before or between ksh invocations, so you can cause a script's
variables to be of the wrong type, or readonly. Backwards
compatibility requires keeping it, at least for now. But it should
be disabled in the posix mode, as it violates POSIX.
To do this, we have to solve a catch-22 in init.c. We must parse
options to know whether to turn on posix mode; it may be specified
as '-o posix' on the command line. The option parsing loop depends
on an initialised environment[*], while environment initialisation
(i.e., importing attributes) should depend on the posix option.
The catch-22 can be solved because initialising just the values
before option parsing is enough to avoid regressions. Importing the
attributes can be delayed until after option parsing. That involves
basically splitting env_init() into two parts while keeping a local
static state variable between them.
src/cmd/ksh93/sh/init.c:
- env_init():
* Split the function in two stages based on a new
'import_attributes' parameter. Import values in the first
stage; import attributes from A__z in the second (if ever).
Make the 'next' variable static as it keeps a state needed for
the attributes import stage.
* Single point of truth, greppability: don't hardcode "A__z" in
separate character comparisons, but use e_envmarker[].
* Fix an indentation error.
- sh_init(): When initialising the environment (env_init), don't
import the attributes from A__z yet; parse options first, then
import attributes only if posix option is not set.
src/cmd/ksh93/sh/name.c:
- sh_envgen(): Don't export variable attributes to A__z if the
posix option is set.
src/cmd/ksh93/tests/attributes.sh:
- Check that variable attributes aren't imported or exported
if the POSIX option is set.
src/cmd/ksh93/sh.1:
- Update.
This was the last item on the TODO list for -o posix for now.
Closes: #20
[*] If environment initialisation is delayed until after option
parsing, bin/shtests shows various regressions, including:
restricted mode breaks; the locale is not initialised properly
so that multibyte variable names break; $SHLVL breaks.
On ksh93, 'test -t' is equivalent to 'test -t 1' (and of course
"[ -t ]" is equivalent to "[ -t 1 ]").
This is purely for compatibility with ancient Bourne shell
breakage. No other shell supports this. ksh93 should probably keep
it for backwards compatibility, but it should definitely be
disabled in POSIX mode as it is a violation of the standard; 'test
-t' is an instance of 'test "$string"', which tests if the string
is empty, so it should test if the string '-t' is empty (quod non).
This also replaces the fix for 'test -t 1' in a command
substitution with a better one that avoids forking (re: cafe33f0).
src/cmd/ksh93/sh/parse.c:
- qscan(): If the posix option is active, disable the parser-based
hack that converts a simple "[ -t ]" to "[ -t 1 ]".
src/cmd/ksh93/bltins/test.c:
- e3(): If the posix option is active, disable the part of the
compatibility hack that was used for compound expressions
that end in '-t', e.g. "[ -t 2 -o -t ]".
- test_unop(): Remove the forking fix for "[ -t 1 ]".
src/cmd/ksh93/edit/edit.c:
- tty_check(): This function is used by "[ -t 1 ]" and in other
contexts as well, so a fix here is more comprehensive. Forking
here would cause a segfault, but we don't actually need to. This
adds a fix that simply returns false if we're in a virtual
subshell that is also a command substitution. Since command
substitutions always fork upon redirecting standard output within
them (making them no longer virtual), it is safe to do this.
src/cmd/ksh93/tests/bracket.sh
- Add comprehensive regression tests for test/[/[[ -t variants in
command substitutions, in simple and compound expressions, with
and without redirecting stdout to /dev/tty within the comsub.
- Add tests verifying that -o posix disables the old hack.
- Tweak other tests, including one that globally disabled xtrace.
eeee77ed implemented a POSIX compliance fix that caused a potential
incompatibility with existing ksh scripts; it made the (rarely
used) read/write redirection operator, <>, default to file
descriptor 0 (standard input) as POSIX specified, instead of 1
(standard output) which is traditional ksh93 behaviour. So ksh
scripts needed to change all <> to 1<> to override the new default.
This commit reverts that change, except in the new posix mode.
src/cmd/ksh93/sh/lex.c:
- Make FD for <> default to 0 in POSIX mode, 1 otherwise.
src/cmd/ksh93/tests/io.sh:
- Revert <> regression test changes from 60516872; we no longer
need 1<> instead of <> in ksh code.
If there are file descriptors > 2 opened with 'exec' or 'redirect',
ksh93 has always closed them when invoking another pogram. This is
contrary to POSIX which states:
Utilities other than the special built-ins […] shall be invoked
in a separate environment that consists of the following. The
initial value of these objects shall be the same as that for
the parent shell, except as noted below.
* Open files inherited on invocation of the shell, open files
controlled by the exec special built-in plus any
modifications, and additions specified by any redirections to
the utility
* […]
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_12
src/cmd/ksh93/sh/io.c: sh_redirect():
- When flag==2, do not close FDs > 2 if POSIX mode is active.
src/cmd/ksh93/tests/io.sh:
- Regress-test inheriting FD 7 with and without POSIX mode.
src/cmd/ksh93/sh.1:
- Update.
Though the "let" builtin is not itself a POSIX standard command, it
processes standard shell arithmetic, so it should recognise octals
by leading zeros as POSIX requires if the 'posix' option is on.
This overrides the setting of the 'letoctal' option.
Note that none of this applies to the ((...)) arithmetic command,
which has always recognised leading-octal zeros and does not listen
to 'letoctal'. So setting the posix mode makes this consistent.
src/cmd/ksh93/sh/arith.c:
- When running the 'let' builtin, test that both SH_LETOCTAL and
SH_POSIX are off before stripping leading zeros to disable octal
number recognition.
- Cosmetic: fix spurious newline.
src/cmd/ksh93/sh.1:
- Document the change.
src/cmd/ksh93/tests/shtests:
- Make sure to disable posix mode by default for regression tests.
On 16 June there was a call for volunteers to fix the bash
compatibility mode; it has never successfully compiled in 93u+.
Since no one showed up, it is now removed due to lack of interest.
A couple of things are kept, which are now globally enabled:
1. The &>file redirection shorthand (for >file 2>&1). As a matter
of fact, ksh93 already supported this natively, but only while
running rc/profile/login scripts, and it issued a warning. This
makse it globally available and removes the warning, bringing
ksh93 in line with mksh, bash and zsh.
2. The '-o posix' standard compliance option. It is now enabled on
startup if ksh is invoked as 'sh' or if the POSIXLY_CORRECT
variable exists in the environment. To begin with, it disables
the aforementioned &> redirection shorthand. Further compliance
tweaks will be added in subsequent commits. The differences will
be fairly minimal as ksh93 is mostly compliant already.
In all changed files, code was removed that was compiled (more
precisely, failed to compile/link) if the SHOPT_BASH preprocessor
identifier was defined. Below are other changes worth mentioning:
src/cmd/ksh93/sh/bash.c,
src/cmd/ksh93/data/bash_pre_rc.sh:
- Removed.
src/cmd/ksh93/data/lexstates.c,
src/cmd/ksh93/include/shlex.h,
src/cmd/ksh93/sh/lex.c:
- Globally enable &> redirection operator if SH_POSIX not active.
- Remove warning that was issued when &> was used in rc scripts.
src/cmd/ksh93/data/options.c,
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/sh/args.c:
- Keep SH_POSIX option (-o posix).
- Replace SH_TYPE_BASH shell type by SH_TYPE_POSIX.
src/cmd/ksh93/sh/init.c:
- sh_type(): Return SH_TYPE_POSIX shell type if ksh was invoked
as sh (or rsh, restricted sh).
- sh_init(): Enable posix option if the SH_TYPE_POSIX shell type
was detected, or if the CONFORMANCE ast config variable was set
to "standard" (which libast sets on init if POSIXLY_CORRECT
exists in the environment).
src/cmd/ksh93/tests/options.sh,
src/cmd/ksh93/tests/io.sh:
- Replace regression tests for &> and move to io.sh. Since &> is
now for general use, no longer test in an rc script, and don't
check that a warning is issued.
Closes: #9
Progresses: #20
This fixes a hanging bug that could occur on macOS when using the
'read' command to read from a FIFO and encountering end-of-file
without a final newline character. It also makes the 'read' command
perform 15-25% faster on macOS and Linux.
The previous version (ff385e5a) failed on SunOS/Solaris/Illumos
because those systems apparently don't (fully) support the POSIX
standard recv(2) syscall with MSG_PEEK[*], which is the feature
that iffe detects under the 'socket_peek' identifier. On Illumos,
using that methods causes a compilation failure (unknown identifier
MSG_PEEK); on Solaris 11.4, that method causes multiple regressions
in tests/io.sh, suggesting the method compiles but doesn't work at
all. Instead, SunOS/Solaris/Illumos requires the method using
ioctl(2)+I_PEEK and select(2). No other system that ksh currently
builds on requires this method, so it is now only used on
SunOS/Solaris/Illumos.
So far, this version of sfpkrd() has been tested to work correctly
on Linux, macOS, FreeBSD, NetBSD, OpenBSD, HP-UX, Solaris, and
OmniOS (an Illumos distribution).
It still fails to peek on Cygwin, but in the exact same way it
failed before, so that's no loss.
To test, run the 'io' test set: bin/shtests -p io
src/lib/libast/sfio/sfpkrd.c: sfpkrd():
- Remove long-obsolete Mac OS X and Solaris bug workarounds.
- Remove methods that are no longer needed.
On systems with a POSIX compliant recv(2), the only thing that
is required to avoid regressions is the code that was conditional
upon the socket_peek feature test, which tests for the correct
functioning of the recv(2) syscall. This has now been made
mandatory for non-SunOS/Solaris/Illumos systems (using an #error
directive if it is not detected), with the other methods removed.
The result performs 15-25% faster on macOS and Linux while
passing all the regression tests.
On macOS, avoiding the select(2) method fixes the hanging bug.
On SunOS/Solaris/Illumos (the '__sun' identifier), the method
using ioctl(2)+I_PEEK and select(2) (iffe feature IDs:
stream_peek and lib_select) is preserved.
Resolves: https://github.com/ksh93/ksh/issues/118 (again)
[*] https://pubs.opengroup.org/onlinepubs/9699919799/functions/recv.html
This fixes a hanging bug that could occur on macOS when using the
'read' command to read from a FIFO and encountering end-of-file
without a final newline character. It also makes the 'read' command
perform 15-25% faster on macOS and Linux and maybe other systems.
src/lib/libast/sfio/sfpkrd.c: sfpkrd():
- Get rid of the optional stuff that uses the poll(2) or select(2)
syscalls. The only thing that is required to avoid regressions is
the code that was conditional upon the socket_peek feature test,
which tests for the correct functioning of the recv(2) syscall.
This has now been made mandatory. The rest now uses what was
previously a fallback in plain C, resulting in a function that is
not only more readable, but actually faster than the syscalls.
Resolves: https://github.com/ksh93/ksh/issues/118
If a command's path was previously added to the hash table as a
'tracked alias', then the hash table entry was used, bypassing
the default utility path search activated by 'command -p'.
'command -p' activates a SH_DEFPATH shell state. The bug was caused
by a failure to check for this state before using the hash table.
This check needs to be added in four places.
src/cmd/ksh93/sh/path.c,
src/cmd/ksh93/sh/xec.c:
- path_search(), path_spawn(), sh_exec(), sh_ntfork(): Only consult
the hash table, which is shp->track_tree, if the SH_DEFPATH shell
state is not active.
src/cmd/ksh93/tests/path.sh:
- Add regress tests checking that 'command -p' and 'command -p -v'
still search in the default path if a hash table entry exists for
the command searched.
'command -x' (basically builtin xargs for 'command') worked for
long argument lists on *BSD and HP-UX, but not on macOS and Linux,
where it reliably entered into an infinite loop.
The problem was that it assumed that every byte of the environment
space can be used for arguments, without accounting for alignment
that some OSs do. MacOS seems to be the most wasteful one: it
aligns on 16-byte boundaries and requires some extra bytes per
argument as well.
src/cmd/ksh93/sh/path.c:
- path_xargs(): When calculating how much space to subtract per
argument, add 16 extra bytes to the length of each argument, then
align the result on 16-byte boundaries. The extra 16 bytes is
more than even macOS needs, but hopefully it is future-proof.
- path_spawn(): If path_xargs() does fail, do not enter a retry
loop (which always becomes an infinite loop if the argument list
exceeds OS limitations), but abort with an error message.
A memory leak occurred upon leaving a virtual subshell if a
function was defined within it. If this was done more than 32766
(= 2^15-2 = the 'short' max value - 1) times, the shell crashed.
Discussion and reproducer: https://github.com/ksh93/ksh/issues/114
src/cmd/ksh93/sh/subshell.c: table_unset():
- A subshell-defined function was never freed because a broken
check for autoloaded functions (which must not be freed[*]). It
looked for an initial '/' in the canonical path of the script
file that defined the function, but that path is also stored for
regular functions. Now use a check that executes nv_search() in
fpathdict, the same method used in _nv_unset() in name.c for a
regular function unset.
src/cmd/ksh93/bltins/misc.c: b_dot_cmd():
- Fix an additional memory leak introduced in bd88cc7f, that caused
POSIX functions (which are run with b_dot_cmd() like dot scripts)
to leak extra. This fix avoids both the crash fixed there and the
memory leak by introducing a 'tofree' variable remembering the
filename to free. Thanks to Johnothan King for the patch.
src/lib/libast/include/stk.h,
src/lib/libast/misc/stk.c,
src/lib/libast/man/stk.3,
src/lib/libast/man/stak.3:
- Make the stack more resilient by extending the stack reference
counter 'stkref' from (signed) short to unsigned int. On modern
systems with 32-bit ints, this extends the maximum number of
elements on a stack from 2^15-1==32767 to 2^32-1==4294967295.
The ref counter can never be negative, so there is no reason for
signedness. sizeof(int) is defined as the size of a single CPU
word, so this should not affect performance at all.
On a 16-bit system (not that ksh still compiles there), this
doubles the max number of entries to 2^16-1=65535.
src/cmd/ksh93/tests/leaks.sh:
- Add leak regression tests for ksh functions, POSIX functions, dot
scripts run with '.', and dot scripts run with 'source'.
src/cmd/ksh93/tests/path.sh:
- Add an output builtin with a redirect to an autoloaded function
so that a crash[*] is triggered if the check for an autoloaded
function is ever removed from table_unset(), as was done in ksh
93v- (which crashed).
[*] Freeing autoloaded functions after leaving a virtual subshell
causes a crashing bug: https://github.com/att/ast/issues/803
Co-authored-by: Johnothan King <johnothanking@protonmail.com>
Fixes: https://github.com/ksh93/ksh/issues/114
Co-authored-by: Martijn Dekker <martijn@inlv.org>
An intermittent crash occurred after running many thousands of
virtual/non-forked subshells. One reproducer is a crash in the
shbench fibonacci.ksh test, as documented here:
https://github.com/ksh-community/shbench/blob/f3d9e134/bench/fibonacci.ksh#L4-L10
The apparent cause was the signed and insufficiently large 'short'
data type of 'curenv' and related variables which wrapped around to
a negative number when overflowing. These IDs are necessary for the
'wait' builtin to obtain the exit status from a background job.
This fix is inspired by a patch based on ksh 93v-:
https://build.opensuse.org/package/view_file/shells/ksh/ksh93-longenv.dif?expand=1https://src.fedoraproject.org/rpms/ksh/blob/f24/f/ksh-20130628-longer.patch
However, we change the type to 'unsigned int' instead of 'long'. On
all remotely modern systems, ints are 32-bit values, and using this
type avoids a performance degradation on 32-bit sytems. Making them
unsigned prevents an overflow to negative values.
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/include/jobs.h,
src/cmd/ksh93/include/nval.h,
src/cmd/ksh93/include/shell.h:
- Change the types of the static global 'subenv' and the subshell
structure members 'curenv', 'jobenv', 'subenv', 'p_env' and
'subshell' to one consistent type, unsigned int.
src/cmd/ksh93/sh/jobs.c,
src/cmd/ksh93/sh/macro.c:
src/cmd/ksh93/sh/name.c:
src/cmd/ksh93/sh/nvtype.c,
src/cmd/ksh93/sh/subshell.c:
- Updates to match new variable types.
src/cmd/ksh93/tests/subshell.sh:
- Show wrong exit status in message on failure of 'wait' builtin.
