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.
The new command substitution mechanism imported in 970069a6 from
Red Hat patches introduced this bug: backtick-style command
substitutions hang when processing about 117KiB of data or more.
It is fixed by another Red Hat patch:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20140415-hokaido.patch
It saves the value of the shp->comsub flag so that it is set to 2
(usually meaning new-style $(comsubs)) in two specific cases even
when processing backtick comsubs. This stops the sh_subtmpfile()
function in subshell.c from creating a /tmp file. However, I think
that approach is quite ugly, so I'm taking a slightly different one
that has the same effect.
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/sh/subshell.c:
- Redefine sh_subtmpfile() to pass the comsub flag as an argument.
(Remove the shp pointer argument, which is redundant; a pointer
to the shell state can easily be obtained in the function.)
src/cmd/ksh93/sh/xec.c: sh_exec():
- Apply the Red Hat fix by passing flag 2 to sh_subtmpfile().
src/cmd/ksh93/tests/subshell.sh:
- Move regress test from ce68e1be from basic.sh to here; this is
the place for command substitution tests as they are subshells.
- Add regress test for this bug.
All other changed files:
- Update sh_subtmpfile() calls to pass on the shp->comsub flag.
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.
When ksh was compiled with SHOPT_SPAWN (the default), any command
substitution embedded in a here-document returned an empty string.
The bug was also present in 93u+ 2012-08-01 (although not in every
case as some systems compile it without SHOPT_SPAWN).
This fixes it by applying a slightly edited combination of two Red
Hat patches (the second containing a fix for the first), which
backport a new command substitution mechanism from the abandoned
ksh 93v- beta version. The originals are:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-macro.patchhttps://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-fd2lost.patch
src/cmd/ksh93/include/io.h:
- The iopipe() function from xec.c is now needed in sh_subshell()
(subshell.c), so rename it to sh_iounpipe() and declare it as an
extern here. The 93v- beta did it as well. (The Red Hat patch did
this without renaming it.)
src/cmd/ksh93/sh/xec.c:
- Backport new versions of iousepipe() and sh_iounpipe() from ksh
93v-. New 'type' flaggery is introduced to distinguish between
different command substitution conditions. What all that means
remains to be determined.
- sh_exec(): I made one change to the Red Hat patch myself: if in a
subshell and the type flags FAMP (for "ampersand" as in '&' as in
background job) and TFORK are set, continue to call sh_subfork()
to fork the subshell unconditionally, instead of only if we're in
a command substitution connected to an unseekable file. Maybe the
latter works for the 93v- code, but on 93u+(m) it causes a couple
of regressions, which are fixed by my change:
signal.sh[273]: subshell ignoring signal does not send signal to parent
signal.sh[276]: subshell catching signal does not send signal to parent
Details: https://github.com/ksh93/ksh/issues/104#issuecomment-696341902
src/cmd/ksh93/sh/macro.c,
src/cmd/ksh93/sh/subshell.c:
- Updates that go with those new functions.
Fixes: https://github.com/ksh93/ksh/issues/104
Affects: https://github.com/ksh93/ksh/issues/124
This fixes two memory leaks in old-style command substitutions
(one when invoking an alias, one when invoking an autoloaded
function), as well as a possible third leak with an unknown
reproducer, by applying this Red Hat patch:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-mlikfiks.patch
src/cmd/ksh93/sh/macro.c: comsubst():
- For as-yet unknown reasons, the alias leak did not occur when
adding a space at the end of the command substitution, as in
a=`some_alias `. This fix is a workaround that simply writes
an extra space to the stack. TODO: a real fix.
src/cmd/ksh93/sh/path.c: funload():
- Add missing free() before return. This fixes the leak with
autoloaded functions.
src/cmd/ksh93/sh/lex.c: alias_exceptf():
- This function is called "whenever an end of string is found with
alias". This adds a check for an SF_FINAL stream status flag when
deciding whether to call free(). In sfio.h this is commented as:
#define SF_FINAL 11 /* closing is done except stream free */
When I revert this change, none of the regression tests fail, so
I don't know how to trigger this supposed leak. But it makes some
sense given the sfio.h comment, so I'll keep it.
src/cmd/ksh93/tests/leaks.sh:
- Add the reproducers from rhbz#982142 as regression tests
(including an extra one for nested command substitutions that was
already fixed as of 93u+, but testing is good).
I replaced the external 'expr' and 'ls' commands by uses of
the 'true' builtin, otherwise the tests take far too long to run
with 16384 iterations. At least the alias leak was still behaving
identically after replacing 'ls' by 'true'.
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 allows running 'bin/shtests leaks' on a ksh without the
vmstate builtin and/or that is not compiled with AST vmalloc.
It falls back to 'ps -o rss= -p $$' to get the memory state.
This is in preparation for the beta and release versions, which
will not use vmalloc due to its defects[*]. Unfortunately,
abandoning vmalloc means abandoning the vmstate builtin which makes
it extremely efficient to test for memory leaks.
Because 'ps' only has a KiB granularity and also shows larger
artefacts/variations than vmalloc on most systems, we need many
more iterations (16384) and also tolerate a higher number of bytes
per iterations (8). So the run takes much longer. To tolerate only
2 bytes per iteration, we would need four times as many iterations,
which would make it take too long to run. Since a single word (e.g.
one pointer) on a 64-bit system is 8 bytes, it still seems very
unlikely for a real memory leak to be that small.
This is coded to make it easy to detect and add iteration and
tolerance parameters for a new method to get the memory state,
if some efficient or precise system-specific way is discovered.
I've also managed to trigger a false leak with shcomp in a UTF-8
locale on CentOS on a ksh with vmalloc/vmstate. So this increases
the tolerance for vmalloc from 2 to 4 bytes/iteration.
[*] Discussion: https://github.com/ksh93/ksh/issues/95
The following set of commands caused ksh to crash:
$ unalias history; unalias r
Memory fault
When ksh is compiled with -D_std_malloc, the crash always
occurs when the 'r' alias is removed with 'unalias r',
although with vmalloc 'unalias history' must be run first
for the crash to occur. With the native malloc, the crash
message is also different:
$ unalias history; unalias r
free(): invalid pointer
Abort
This crash happens because when an alias is unset, _nv_unset
removes the NV_NOFREE flag which results in an invalid use
of free(3) as nv_isattr no longer detects NV_NOFREE afterward.
The history and r aliases shouldn't be freed from memory by
nv_delete because those aliases are given the NV_NOFREE attribute.
src/cmd/ksh93/bltins/typeset.c:
- Save the state of NV_NOFREE for aliases to fix the crash
caused by 'unalias r'.
src/cmd/ksh93/tests/alias.sh:
- Use unalias on both history and r to check for the crash.
'unalias -a' can't be used to replicate the crash.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
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.
A memory leak occurred when typeset was used in a function called
from within a command substitution. This fix was backported from
the 93v- beta by Red Hat on 22 Jan 2014. Source:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-memlik3.patch
src/cmd/ksh93/include/name.h,
src/cmd/ksh93/sh/subshell.c:
- Replace the nv_subsaved() function by the version from ksh 93v-.
This version frees a table from memory if the NV_TABLE flag is
passed in the new second parameter, a bitmask for flags (which
was oddly named 'table'; I've renamed it to 'flags').
src/cmd/ksh93/sh/name.c:
- nv_delete(): When calling nv_subsaved(), pass on the NV_TABLE
flag if given.
- table_unset(): Call nv_delete() with the NV_TABLE flag.
src/cmd/ksh93/tests/leaks.sh:
- Add test based on the reproducer provided in Red Hat bug 1036470.
I now have access to some of the private bugs on the Red Hat bug
tracker. This one doesn't have a lot of information on the patch,
but it contains a good reproducer, so we can at least verify that
it works.
src/cmd/ksh93/sh/array.c,
src/cmd/ksh93/sh/name.c:
- Apply the patch associated with Red Hat bug #921455. Source:
https://src.fedoraproject.org/rpms/ksh/blob/642af4d6/f/ksh-20120801-memlik.patch
This was applied to Red Hat's ksh on 04 Jul 2013.
src/cmd/ksh93/tests/leaks.sh:
- Add leak tests for associative and indexed arrays in functions
based on the reproducer from rhbz#921455.
- Both tests still leak (though much less) when run in a locale
other than C. For now, temporarily set the locale to C and add
a TODO note. Perhaps another Red Hat patch is yet to fix this.
_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.
The fix was incomplete: expansions using '?' (${var?w(ord},
${var:?wo)rd}) still did not tolerate parentheses in the word
as regular characters.
It was also possible to simplify the fix by making use of the
ST_BRACE (sh_lexstate7[]) state table. See data/lexstates.c and
include/lexstates.h.
src/cmd/ksh93/sh/lex.c: sh_lex(): case S_MOD1:
- The previous fix tested for modifier operator characters : - + =
as part of the S_MOD2 case, though they are defined as S_MOD1 in
the ST_BRACE state table. It only worked because of the
fallthrough. And it turns out the S_MOD1 case already had a
similar fix, though incomplete. The new fix effectively cancelled
the old one out as any S_MOD1 character eventually led to
'continue'. So it can be simplified by removing most of that
code, without causing any change in behaviour. Only the mode
change to the ST_QUOTE state table followed by 'continue' is
necessary. This also fixes it for the '?' operator as that is
also defined as S_MOD1 in the ST_BRACE state table.
src/cmd/ksh93/sh/macro.c:
- When skipping a ${...} expansion using sh_lexskip(), use the
ST_QUOTE state table if the character c is an S_MOD1 modifier
operator character. This makes it consistent with the S_MOD1
handling in sh_lex().
src/cmd/ksh93/tests/variables.sh:
- Update regression tests to include ? and :? operators.
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
A coprocess cleanup test could fail on rare occasions because I had
lowered the 'sleep 1' between two test coprocesses to 'sleep .1'.
This increases the sleep to prevent future spurious fails.
Fixes: https://github.com/ksh93/ksh/issues/129
Using a process of elimination I've identified ${.sh.level}
(SH_LEVELNOD) as the cause of the crash. This node apparently
cannot be copied or moved without destabilising the shell. It
contains the current depth of function calls and it cannot be
changed by assignment, so this is not actually a problem.
Meanwhile, this commit re-fixes it for the other three.
src/cmd/ksh93/sh/subshell.c:
- Simplify sh_assignok() by removing special-casing for L_ARGNOD,
SH_SUBSCRNOD and SH_NAMENOD. 'add' now has 3 modes (0, 1, 2).
- The test for a ${ subshare; } was actually wrong. sp->subshare is
a saved backup value. We must test shp->subshare. (re: a9de50bf)
src/cmd/ksh93/bltins/typeset.c:
- setall(): Update the mode 3 sh_assignok() call.
src/cmd/ksh93/tests/variables.sh:
- Regress-test subshell leaks for all special variables except
${.sh.level}.
This reverts commit b3d37b00b0.
While ksh's own regression test suite passed just fine, when
running the modernish[*] regression tests uite, ksh either froze
hard (needing SIGKILL) or threw a spurious syntax error.
Cause unknown, but I'm certainly reverting until I find out.
This reintroduces a subshell leak for four special variables.
[*] https://github.com/modernish/modernish
${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
The following special variables leaked out of a subshell:
$_, ${.sh.name}, ${.sh.level}, ${.sh.subscript}.
This was due to a faulty optimisation in sh_assignok().
bd3e2a80 fixed that in part, this fixes the rest.
src/cmd/ksh93/sh/subshell.c:
- Simplify sh_assignok() by removing special-casing for these four
special variables. The 'add' param reverts to a simple boolean.
- The test for a ${ subshare; } was actually wrong. sp->subshare is
a saved backup value. We must test shp->subshare. (re: a9de50bf)
src/cmd/ksh93/bltins/typeset.c:
- setall(), unall(): Update sh_assignok() calls.
src/cmd/ksh93/tests/variables.sh:
- Regress-test subshell leaks for all special variables.
Closes: #122
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; $SHLVL breaks.
In the SHOPT_BASH code, the -o posix option was given a '\374'
(0xFC, 252) single-letter option character. Reasons unclear. The
'set' builtin doesn't accept it. It can be omitted and the option
still works. And it caused the "$-" expansion (listing active
short-form options) to include that invalid high-bit character if
the -o posix option is active, which is clearly wrong.
src/cmd/ksh93/sh/args.c: optksh[], flagval[]:
- Remove '\374' one-letter option equivalent for SH_POSIX.
src/cmd/ksh93/tests/options.sh:
- Add test verifying that '-o posix' does not affect "$-".
The inclusion of the special parameter expansions ${!} and ${$}
(including the braces) in a here-document caused a syntax error.
Bug reported by @Saikiran-m on Github.
src/cmd/ksh93/data/lexstates.c: sh_lexstate7[]:
- Change the state for ! (33) and $ (36) from S_ERR to 0. State
table 7 is for skipping over ${...}, so this avoids the S_ERR
state being invoked in sh_lex() (lex.c) for these characters
while skipping ${...} in a here-doc.
src/cmd/ksh93/tests/heredoc.sh:
- Test evaluating the braces expansion form for all special
parameters (@ * # ! $ - ? 0) in a here-document.
Fixes: https://github.com/ksh93/ksh/issues/127
An oops in tests/io.sh (re: c607c48c) wrote temporary files outside
$tmp and into src/cmd/ksh93/tests. Let's fix this properly so it
doesn't happen again.
src/cmd/ksh93/tests/shtests:
- Start each test set in its own temporary directory by default.
src/cmd/ksh93/tests/*.sh:
- Refuse to run if $tmp != $PWD.
- Related cleanups.
On ksh93, 'test -t' is equivalent to 'test -t 1' (and of course
"[ -t ]" is equivalent to "[ -t 1 ]").
This is purely for compatibility with ancient Bourne shell
breakage. No other shell supports this. ksh93 should probably keep
it for backwards compatibility, but it should definitely be
disabled in POSIX mode as it is a violation of the standard; 'test
-t' is an instance of 'test "$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.
