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; $SHLVL breaks.
This commit removes the following standards check on init:
strcmp(astconf("CONFORMANCE",0,0),"standard")==0
This also checks for the POSIXLY_CORRECT variable; the libast
configuration system uses it to set "CONFORMANCE" to "standard",
*but*, only if that parameter wasn't already initialised from the
_AST_FEATURES environment variable (see 'getconf --man').
Problem is, there is a harmful interaction between POSIXLY_CORRECT
and _AST_FEATURES. If the latter exists, it overrides the former.
Not only that, merely querying CONFORMANCE makes astconf create and
export the _AST_FEATURES variable, propagating the current setting
to child ksh processes, which will then ignore POSIXLY_CORRECT.
We could get around this by simply using getenv("POSIXLY_CORRECT").
But then the results may be inconsistent with the AST config state.
The whole thing may not be the best idea anyway. Honouring
POSIXLY_CORRECT at startup introduces a backwards compatibility
issue. Existing scripts or setups may export POSIXLY_CORRECT=y to
put external GNU utilities in standards mode, while still expecting
traditional ksh behaviour from newly initialised shells.
So it's probably better to just get rid of the check. This is not
bash, after all. If ksh is invoked as sh (the POSIX standard
command name), or with '-o posix' on the command line, you get the
standards mode; that ought to be good enough.
src/cmd/ksh93/sh/init.c: sh_init():
- Remove astconf call as per above.
In the SHOPT_BASH code, the -o posix option was given a '\374'
(0xFC, 252) single-letter option character. Reasons unclear. The
'set' builtin doesn't accept it. It can be omitted and the option
still works. And it caused the "$-" 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
Since ksh 93u+m comes bundled with libast 20111111, there's no need
to support older versions, so this is another cleanup opportunity.
src/cmd/ksh93/include/defs.h:
- Throw an #error if AST_VERSION is undefined or < 20111111.
(Note that _AST_VERSION is the same as AST_VERSION, but the
latter is newer and preferred; see src/lib/libast/features/api)
All other changed files:
- Remove legacy code for versions older than the currently used
versions, which are:
_AST_VERSION 20111111
ERROR_VERSION 20100309
GLOB_VERSION 20060717
OPT_VERSION 20070319
SFIO_VERSION 20090915
VMALLOC_VERSION 20110808
SHOPT_ENV is an undocumented compile-time option implementing an
experimental method for handling environment variables, which is
implemented in env.h and env.c. There is no mention in the docs or
Makefile, and no mention in the mailing list archives. It adds no
new functionality, but at first glance it's a clean-looking
interface.
However, unfortunately, it's broken. Compiling with -DSHOPT_ENV
added to CCFLAGS causes bin/shtests to show these regressions:
functions.sh[341]: export not restored name=value function call -- expected 'base', got ''
functions.sh[1274]: Environment variable is not passed to a function
substring.sh[236]: export not restored name=value function call
variables.sh[782]: SHLVL should be 3 not 2
In addition, 'export' stops working on unset variables.
In the 93v- beta this code is still present, unchanged, though 93v-
made lots of incompatible changes. By the time ksh2020 noticed it,
it was no longer compiling, so it probably wasn't compiling in the
93v- beta either. Discussion: https://github.com/att/ast/issues/504
So the experiment was already abandoned by D. Korn and his team.
Meanwhile it was leaving sh/name.c with two versions of several
enviornment-related functions, and it's not clear which one is
actually compiled without doing detective work tracing header files
(most of the code was made conditional on _ENV_H, which is defined
in env.h, which is included by defs.h if SHOPT_ENV is defined).
This actively hinders understanding of the codebase. And any
changes to these functions would need to be implemented twice.
src/cmd/ksh93/include/env.h,
src/cmd/ksh93/sh/env.c:
- Removed.
src/cmd/ksh93/DESIGN,
src/cmd/ksh93/Makefile,
src/cmd/ksh93/Mamfile:
- Update accordingly.
All other changed files:
- Remove deactivated code behind SHOPT_ENV and _ENV_H.
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.
ksh was enabling POSIX mode on init if it was invoked as any name
that merely started with 'sh' (after parsing initial 'r'). This
included shcomp, which was bad news.
src/cmd/ksh93/sh/init.c: sh_type():
- Check that the 'sh' is at the end of the string by checking
for a final zero byte.
- On Windows (_WINIX, see src/lib/libast/features/common), allow
for a file name extension (sh.exe) by checking for a dot as well.
eeee77ed implemented a POSIX compliance fix that caused a potential
incompatibility with existing ksh scripts; it made the (rarely
used) read/write redirection operator, <>, default to file
descriptor 0 (standard input) as POSIX specified, instead of 1
(standard output) which is traditional ksh93 behaviour. So ksh
scripts needed to change all <> to 1<> to override the new default.
This commit reverts that change, except in the new posix mode.
src/cmd/ksh93/sh/lex.c:
- Make FD for <> default to 0 in POSIX mode, 1 otherwise.
src/cmd/ksh93/tests/io.sh:
- Revert <> regression test changes from 60516872; we no longer
need 1<> instead of <> in ksh code.
If there are file descriptors > 2 opened with 'exec' or 'redirect',
ksh93 has always closed them when invoking another pogram. This is
contrary to POSIX which states:
Utilities other than the special built-ins […] shall be invoked
in a separate environment that consists of the following. The
initial value of these objects shall be the same as that for
the parent shell, except as noted below.
* Open files inherited on invocation of the shell, open files
controlled by the exec special built-in plus any
modifications, and additions specified by any redirections to
the utility
* […]
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_12
src/cmd/ksh93/sh/io.c: sh_redirect():
- When flag==2, do not close FDs > 2 if POSIX mode is active.
src/cmd/ksh93/tests/io.sh:
- Regress-test inheriting FD 7 with and without POSIX mode.
src/cmd/ksh93/sh.1:
- Update.
Though the "let" builtin is not itself a POSIX standard command, it
processes standard shell arithmetic, so it should recognise octals
by leading zeros as POSIX requires if the 'posix' option is on.
This overrides the setting of the 'letoctal' option.
Note that none of this applies to the ((...)) arithmetic command,
which has always recognised leading-octal zeros and does not listen
to 'letoctal'. So setting the posix mode makes this consistent.
src/cmd/ksh93/sh/arith.c:
- When running the 'let' builtin, test that both SH_LETOCTAL and
SH_POSIX are off before stripping leading zeros to disable octal
number recognition.
- Cosmetic: fix spurious newline.
src/cmd/ksh93/sh.1:
- Document the change.
src/cmd/ksh93/tests/shtests:
- Make sure to disable posix mode by default for regression tests.
On 16 June there was a call for volunteers to fix the bash
compatibility mode; it has never successfully compiled in 93u+.
Since no one showed up, it is now removed due to lack of interest.
A couple of things are kept, which are now globally enabled:
1. The &>file redirection shorthand (for >file 2>&1). As a matter
of fact, ksh93 already supported this natively, but only while
running rc/profile/login scripts, and it issued a warning. This
makse it globally available and removes the warning, bringing
ksh93 in line with mksh, bash and zsh.
2. The '-o posix' standard compliance option. It is now enabled on
startup if ksh is invoked as 'sh' or if the POSIXLY_CORRECT
variable exists in the environment. To begin with, it disables
the aforementioned &> redirection shorthand. Further compliance
tweaks will be added in subsequent commits. The differences will
be fairly minimal as ksh93 is mostly compliant already.
In all changed files, code was removed that was compiled (more
precisely, failed to compile/link) if the SHOPT_BASH preprocessor
identifier was defined. Below are other changes worth mentioning:
src/cmd/ksh93/sh/bash.c,
src/cmd/ksh93/data/bash_pre_rc.sh:
- Removed.
src/cmd/ksh93/data/lexstates.c,
src/cmd/ksh93/include/shlex.h,
src/cmd/ksh93/sh/lex.c:
- Globally enable &> redirection operator if SH_POSIX not active.
- Remove warning that was issued when &> was used in rc scripts.
src/cmd/ksh93/data/options.c,
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/sh/args.c:
- Keep SH_POSIX option (-o posix).
- Replace SH_TYPE_BASH shell type by SH_TYPE_POSIX.
src/cmd/ksh93/sh/init.c:
- sh_type(): Return SH_TYPE_POSIX shell type if ksh was invoked
as sh (or rsh, restricted sh).
- sh_init(): Enable posix option if the SH_TYPE_POSIX shell type
was detected, or if the CONFORMANCE ast config variable was set
to "standard" (which libast sets on init if POSIXLY_CORRECT
exists in the environment).
src/cmd/ksh93/tests/options.sh,
src/cmd/ksh93/tests/io.sh:
- Replace regression tests for &> and move to io.sh. Since &> is
now for general use, no longer test in an rc script, and don't
check that a warning is issued.
Closes: #9
Progresses: #20
Following a community objection to its removal, the inline 'test'
manual page along with its strange method of invocation is
restored. I've taken the opportunity to correct several mistakes,
add some missing info, do some copy-editing, and document the way
to get these docs in the main (k)sh.1 manual.
Discussion:
https://github.com/ksh93/ksh/commit/fa6a180f#commitcomment-41897553
Did you know that you could get a manual page for the 'test'/'['
builtin command using one of these strange command lines?
test --man --
[ --man -- ]
Neither did I. It's not documented or mentioned anywhere (and this
syntax violates POSIX). So nobody knows about it, which makes that
documentation useless. (The regular --man option doesn't work
because that would break 'test'.) I only found out how to invoke it
when I understood what the uncommented C code handling this does.
The test/[ command's self-documentation is unmaintained since 2003
and somewhat incomplete. It's also mostly redundant with the
documentation on Conditional Expressions in the main (k)sh.1 manual
page. But unlike the latter, this is resident in RAM, wasting
working memory in every shell process.
src/cmd/ksh93/sh.1:
- Add documentation for 'test'/'[' commands (yes, they were not
mentioned in the main manual page until now), describing them
in terms of differences from '[[' and recommending the latter.
src/cmd/ksh93/include/test.h,
src/cmd/ksh93/bltins/test.c,
src/cmd/ksh93/data/testops.c:
- Remove RAM-resident --man doc for test/[ command.
- Remove the bizarre option parsing that allowed invoking it.
Instead of a global 'sh_in_test_builtin' integer flag, it is nicer
to use the mechanism for shell state bits, which was designed for
this sort of thing.
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/sh/defs.c:
- Remove global sh_in_test_builtin integer.
- Define new SH_INTESTCMD state bit.
src/cmd/ksh93/bltins/test.c: _ERROR_exit_b_test(), b_test():
- Use the new state bit.
This removes various blocks of uncommented experimental code that
was disabled using '#if 0' or '#if 1 ... #else' directives. It's
hard or impossible to figure out what the thoughts behind them
might have been, and we can really do without those distractions.
As of 8477d2ce, the mbwide() macro (which tests if we're in a
multibyte locale, i.e. UTF-8) is redefined as a constant 0 if we're
compiling without SHOPT_MULTIBYTE. See src/cmd/ksh93/include/defs.h
The other multibyte macros use mbwide() as well, so they all revert
to the single-byte fallbacks in that case, and the multibyte code
in them is never compiled. See src/lib/libast/include/ast.h
Consequently we can now do a bit of cleanup and get rid of many of
the '#if SHOPT_MULTIBYTE' directives, as the compiler optimiser
will happily remove the multibyte-specific code. This increases the
legibility of the ksh code.
I'm taking the opportunity to fix a few typos and whitespace
formatting glitches as well.
The first of the two multibyte fixes from 8b5f11dc (which was for
using the first character of IFS as an output field separator when
expanding "$*" and similar) had a minor backwards compatibility
problem: if $IFS started with a byte sequence that is not a valid
UTF-8 character, then it treated IFS as empty in UTF-8 locales, so
the fields would be joined without any separator. The expected
behaviour would be for it to fall back to using the first byte of
IFS as it used to (and as bash and zsh do).
The new code handling this was also a bit kludgy and inefficient,
repeating the mbsize() calculation for every byte of the separator
character and for every field joined by the expansion.
src/cmd/ksh93/sh/macro.c: varsub():
- Rewrite code for joining fields for $* in a quoted or scalar
context and $@ in a scalar context, eliminating a confusing 'd'
variable and concentrating the routine in one block.
- When expanding $* with a multibyte separator (first character
of $IFS), only calculate the size in bytes once per expansion.
- If $IFS starts with a byte sequence that represents an invalid
multibyte character, fall back to using the first byte.
src/cmd/ksh93/tests/variables.sh:
- Tweak some regression tests, including one that overwrote $LANG.
- Add test for invalid multibyte character behaviour as per above.
src/cmd/ksh93/sh/path.c: canexecute():
- Close file descriptors inside of the err label. This fixes
a file descriptor leak that occurs when open succeeds but
fstat fails with EIO. The previous code only returned -1
after 'goto err', leaving the opened file descriptor
inaccessible. This bugfix was backported from ksh2020:
https://github.com/att/ast/commit/55cad1d
The package script searches for a good shell to run the build
scripts, preferring a ksh. But it also finds any recently compiled
development version of ksh in arch/*/bin that may be broken, or
have debug code, etc. -- and uses that in preference to anything
else. This is quite capable of breaking the build process.
The way to get around it is to do something like
bin/package make SHELL=/bin/ksh
which is annoying to have to keep doing.
bin/package,
src/cmd/INIT/package.sh:
- When finding a good shell, use the saved user path ($path), not
the current $PATH which includes arch/$HOSTTYPE/bin. Prefix this
temporary path with `getconf PATH`, the system's default path,
so that known-good system shells are found first.
All changed files:
- Put the shell in POSIX mode if it has an '-o posix' option.
- Remove nonsense disabling 'set -x' on bash. It's not broken.
bin/package, src/cmd/INIT/package.sh:
- Add check blocking native zsh mode (e.g., "$path" conflicts).
Using a 'sh -> zsh' symlink works, so recommend that.
- Remove old ksh93 version check for a supposed conflict with
libcmd. It was broken; it would revert to /bin/sh, but on illumos
distributions, /bin/sh is a ksh93 of a version that is supposedly
affected. It builds fine anyway.
- Rewrite checksh() to incorporate the shell compatibility checks
that were previously in two different places in 'package'.
bin/ignore, src/cmd/INIT/ignore.sh,
bin/silent, src/cmd/INIT/silent.sh:
- Change bad check for a full POSIX 'export' command (no, $RANDOM
has nothing to do with that) with a proper feature test.
The shell detection test assumed that any shell that has $RANDOM
and isn't bash must be ksh and have the 'print' built-in command.
This broke iffe on NetBSD 9.0 sh, which has $RANDOM but not 'print'.
src/cmd/INIT/iffe.sh:
- Rewrite shell detection test to test for features actually used
by iffe. "$shell" can now have the values 'bsh' for an ancient
pre-POSIX Bourne shell, 'bash' for bash, 'ksh' for a shell with
'let', 'typeset -u' and 'print' (ksh88, ksh93, mksh, pdksh, zsh),
and 'posix' for another POSIX or POSIX-ish shell with modern
command substitutions and parameter substitutions. (The 'posix'
value currently is not actively checked for anywhere, but avoids
unnecessary use of bsh fallbacks.)
If ksh was compiled with -DSHOPT_REGRESS=1, it would immediately
segfault on init. After fixing that, another segfault remained that
occurred when using the --regress= command line option with an
invalid option-argument.
The __regress__ builtin allows tracing a few things (see
'__regress__ --man' after compiling with -DSHOPT_REGRESS=1, or
usage[] in src/cmd/ksh93/bltins/regress.c). It seems of limited
use, but at least it can be used/tested now.
src/cmd/ksh93/sh/init.c: sh_init():
- Move the call to sh_regress_init() up. The crash on init was
caused by geteuid() being intercepted by regress.c before the
shp->regress (== sh.regress) pointer was initialised.
- The builtin can also be called using a --regress= option-argument
on the ksh command line. Before calling b___regress__() to parse
that, temporarily change error_info.exit so any usage error calls
exit(3) instead of sh_exit(), as the latter assumes a fully
defined shell state and this call is done before the shell is
fully initialised.
The INIT scripts are supposed to be Bourne shell scripts, not
POSIX, so we can't use $( ... ) command substitutions.
bin/package,
src/cmd/INIT/package.sh:
- Change a POSIX command substitution to old-style backticks.
This fixes a hanging bug that could occur on macOS when using the
'read' command to read from a FIFO and encountering end-of-file
without a final newline character. It also makes the 'read' command
perform 15-25% faster on macOS and Linux.
The previous version (ff385e5a) failed on SunOS/Solaris/Illumos
because those systems apparently don't (fully) support the POSIX
standard recv(2) syscall with MSG_PEEK[*], which is the feature
that iffe detects under the 'socket_peek' identifier. On Illumos,
using that methods causes a compilation failure (unknown identifier
MSG_PEEK); on Solaris 11.4, that method causes multiple regressions
in tests/io.sh, suggesting the method compiles but doesn't work at
all. Instead, SunOS/Solaris/Illumos requires the method using
ioctl(2)+I_PEEK and select(2). No other system that ksh currently
builds on requires this method, so it is now only used on
SunOS/Solaris/Illumos.
So far, this version of sfpkrd() has been tested to work correctly
on Linux, macOS, FreeBSD, NetBSD, OpenBSD, HP-UX, Solaris, and
OmniOS (an Illumos distribution).
It still fails to peek on Cygwin, but in the exact same way it
failed before, so that's no loss.
To test, run the 'io' test set: bin/shtests -p io
src/lib/libast/sfio/sfpkrd.c: sfpkrd():
- Remove long-obsolete Mac OS X and Solaris bug workarounds.
- Remove methods that are no longer needed.
On systems with a POSIX compliant recv(2), the only thing that
is required to avoid regressions is the code that was conditional
upon the socket_peek feature test, which tests for the correct
functioning of the recv(2) syscall. This has now been made
mandatory for non-SunOS/Solaris/Illumos systems (using an #error
directive if it is not detected), with the other methods removed.
The result performs 15-25% faster on macOS and Linux while
passing all the regression tests.
On macOS, avoiding the select(2) method fixes the hanging bug.
On SunOS/Solaris/Illumos (the '__sun' identifier), the method
using ioctl(2)+I_PEEK and select(2) (iffe feature IDs:
stream_peek and lib_select) is preserved.
Resolves: https://github.com/ksh93/ksh/issues/118 (again)
[*] https://pubs.opengroup.org/onlinepubs/9699919799/functions/recv.html
This fixes a hanging bug that could occur on macOS when using the
'read' command to read from a FIFO and encountering end-of-file
without a final newline character. It also makes the 'read' command
perform 15-25% faster on macOS and Linux and maybe other systems.
src/lib/libast/sfio/sfpkrd.c: sfpkrd():
- Get rid of the optional stuff that uses the poll(2) or select(2)
syscalls. The only thing that is required to avoid regressions is
the code that was conditional upon the socket_peek feature test,
which tests for the correct functioning of the recv(2) syscall.
This has now been made mandatory. The rest now uses what was
previously a fallback in plain C, resulting in a function that is
not only more readable, but actually faster than the syscalls.
Resolves: https://github.com/ksh93/ksh/issues/118
CDE <https://cdesktopenv.sf.net/> developer Chase writes, re dtksh:
| Everything is now completely working, and we are almost ready to
| add ksh93 as a submodule, but I have one last commit to get rid
| of some warnings we are facing. nval.h has some of these
| "compatiblity redefines" that are causing issues whenever we
| include it (warnings about redefining values) [...].
src/cmd/ksh93/include/nval.h:
- Replace ancient compatibility redefines by an unconditional
'#include <hash.h>'; ksh works fine with the "new" hash library.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
If a command's path was previously added to the hash table as a
'tracked alias', then the hash table entry was used, bypassing
the default utility path search activated by 'command -p'.
'command -p' activates a SH_DEFPATH shell state. The bug was caused
by a failure to check for this state before using the hash table.
This check needs to be added in four places.
src/cmd/ksh93/sh/path.c,
src/cmd/ksh93/sh/xec.c:
- path_search(), path_spawn(), sh_exec(), sh_ntfork(): Only consult
the hash table, which is shp->track_tree, if the SH_DEFPATH shell
state is not active.
src/cmd/ksh93/tests/path.sh:
- Add regress tests checking that 'command -p' and 'command -p -v'
still search in the default path if a hash table entry exists for
the command searched.
'command -x' (basically builtin xargs for 'command') worked for
long argument lists on *BSD and HP-UX, but not on macOS and Linux,
where it reliably entered into an infinite loop.
The problem was that it assumed that every byte of the environment
space can be used for arguments, without accounting for alignment
that some OSs do. MacOS seems to be the most wasteful one: it
aligns on 16-byte boundaries and requires some extra bytes per
argument as well.
src/cmd/ksh93/sh/path.c:
- path_xargs(): When calculating how much space to subtract per
argument, add 16 extra bytes to the length of each argument, then
align the result on 16-byte boundaries. The extra 16 bytes is
more than even macOS needs, but hopefully it is future-proof.
- path_spawn(): If path_xargs() does fail, do not enter a retry
loop (which always becomes an infinite loop if the argument list
exceeds OS limitations), but abort with an error message.
Four libast hash functions/macros (which ksh93 doesn't actually use)
were overridden with the following comment:
/*
* These following are for binary compatibility with the old hash library
* They will be removed someday
*/
This has been there for decades, and I just received word that they
cause problems for the dtksh (CDE) developers as dtksh does call
hashlook().
src/cmd/ksh93/sh/name.c:
- Remove 'hashscope', 'hashfree', 'hashname' and 'hashlook'
compatibility overrides.
A memory leak occurred upon leaving a virtual subshell if a
function was defined within it. If this was done more than 32766
(= 2^15-2 = the 'short' max value - 1) times, the shell crashed.
Discussion and reproducer: https://github.com/ksh93/ksh/issues/114
src/cmd/ksh93/sh/subshell.c: table_unset():
- A subshell-defined function was never freed because a broken
check for autoloaded functions (which must not be freed[*]). It
looked for an initial '/' in the canonical path of the script
file that defined the function, but that path is also stored for
regular functions. Now use a check that executes nv_search() in
fpathdict, the same method used in _nv_unset() in name.c for a
regular function unset.
src/cmd/ksh93/bltins/misc.c: b_dot_cmd():
- Fix an additional memory leak introduced in bd88cc7f, that caused
POSIX functions (which are run with b_dot_cmd() like dot scripts)
to leak extra. This fix avoids both the crash fixed there and the
memory leak by introducing a 'tofree' variable remembering the
filename to free. Thanks to Johnothan King for the patch.
src/lib/libast/include/stk.h,
src/lib/libast/misc/stk.c,
src/lib/libast/man/stk.3,
src/lib/libast/man/stak.3:
- Make the stack more resilient by extending the stack reference
counter 'stkref' from (signed) short to unsigned int. On modern
systems with 32-bit ints, this extends the maximum number of
elements on a stack from 2^15-1==32767 to 2^32-1==4294967295.
The ref counter can never be negative, so there is no reason for
signedness. sizeof(int) is defined as the size of a single CPU
word, so this should not affect performance at all.
On a 16-bit system (not that ksh still compiles there), this
doubles the max number of entries to 2^16-1=65535.
src/cmd/ksh93/tests/leaks.sh:
- Add leak regression tests for ksh functions, POSIX functions, dot
scripts run with '.', and dot scripts run with 'source'.
src/cmd/ksh93/tests/path.sh:
- Add an output builtin with a redirect to an autoloaded function
so that a crash[*] is triggered if the check for an autoloaded
function is ever removed from table_unset(), as was done in ksh
93v- (which crashed).
[*] Freeing autoloaded functions after leaving a virtual subshell
causes a crashing bug: https://github.com/att/ast/issues/803
Co-authored-by: Johnothan King <johnothanking@protonmail.com>
Fixes: https://github.com/ksh93/ksh/issues/114
The fix was incomplete because some tests have to unset HISTFILE,
which reverted them to using ~/.sh_history by default.
src/cmd/ksh93/tests/shtests:
- Instead of setting HISTFILE, set HOME to the temporary directory
$tmp, so nothing will write to the real user directory and the
default history file is $tmp/.sh_history.
src/cmd/ksh93/tests/attributes.sh:
- Restore HISTFILE after a test that requires setting HISTFILE=foo.
src/cmd/ksh93/bltins/print.c:
- If in UTF-8 locale, only bother to check for unreserved char if
the character is ASCII (< 128), and write unreserved chars with
a simple stakputc().
Co-authored-by: Martijn Dekker <martijn@inlv.org>
An intermittent crash occurred after running many thousands of
virtual/non-forked subshells. One reproducer is a crash in the
shbench fibonacci.ksh test, as documented here:
https://github.com/ksh-community/shbench/blob/f3d9e134/bench/fibonacci.ksh#L4-L10
The apparent cause was the signed and insufficiently large 'short'
data type of 'curenv' and related variables which wrapped around to
a negative number when overflowing. These IDs are necessary for the
'wait' builtin to obtain the exit status from a background job.
This fix is inspired by a patch based on ksh 93v-:
https://build.opensuse.org/package/view_file/shells/ksh/ksh93-longenv.dif?expand=1https://src.fedoraproject.org/rpms/ksh/blob/f24/f/ksh-20130628-longer.patch
However, we change the type to 'unsigned int' instead of 'long'. On
all remotely modern systems, ints are 32-bit values, and using this
type avoids a performance degradation on 32-bit sytems. Making them
unsigned prevents an overflow to negative values.
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/include/jobs.h,
src/cmd/ksh93/include/nval.h,
src/cmd/ksh93/include/shell.h:
- Change the types of the static global 'subenv' and the subshell
structure members 'curenv', 'jobenv', 'subenv', 'p_env' and
'subshell' to one consistent type, unsigned int.
src/cmd/ksh93/sh/jobs.c,
src/cmd/ksh93/sh/macro.c:
src/cmd/ksh93/sh/name.c:
src/cmd/ksh93/sh/nvtype.c,
src/cmd/ksh93/sh/subshell.c:
- Updates to match new variable types.
src/cmd/ksh93/tests/subshell.sh:
- Show wrong exit status in message on failure of 'wait' builtin.
As of aa4669ad, astconf("PATH") is implemented as a hardcoded AST
configuration variable that always has a value, instead of one that
falls back on the OS. Its value is now obtained from the OS (with a
fallback) at configure time and not at runtime. This means that any
fallback for astconf("PATH") is now never used.
src/cmd/ksh93/data/msg.c,
src/cmd/ksh93/include/shell.h:
- Remove e_defpath[]. (The path "/bin:/usr/bin:" made no sense as a
default path anyway, as the final empty element is wrong: default
utilities should never be sought in the current working dir.)
src/cmd/ksh93/sh/path.c,
src/lib/libast/path/pathbin.c:
- abort() if astconf("PATH") returns null.
src/lib/libast/comp/conf.tab: PATH:
- If no 'getconf' utility can be found, use a fallback path that
finds more utilities by also searching in 'sbin' directories.
On some systems, this is needed to find chown(1).
src/cmd/ksh93/sh.1:
- Update doc re default path.
Using the bin/shtests -l/--locale option to run the regression
tests in your own locale broke the tests if you're in a locale that
uses ',' as the radix point, like my nl_NL.UTF-8, unless
LC_NUMERIC=C was exported manually. Let's automate that fix.
src/cmd/ksh93/tests/shtests: --locale:
- If LC_ALL was set, copy it to LANG and unset all LC_* vars.
This allows overriding the radix point with LC_NUMERIC if needed.
- If '1.0' is not a valid shell arithmetic expression, export
LC_NUMERIC=C to fix it.
