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
