This commit was originally intended to fix just one bug with shcomp's
handling of 'alias -p', but while fixing that I found a large number
of related issues in the alias command's -p, -t and -x options. The
current patch provides bugfixes for all of the bugs listed below:
1) Listing aliases in a script with 'alias -p' or 'alias' broke
shcomp's bytecode output:
https://github.com/ksh93/ksh/issues/87#issuecomment-813819122
2) Listing individual aliases with the -p option doesn't work:
$ alias foo=bar bar=foo
$ alias foo
foo=bar
$ alias -p foo # No output
3) Listing specific tracked aliases with -pt does not display them
in a reusable format, but rather adds another tracked alias:
$ hash -r cat vi
$ alias -pt vi # No output
$ alias -pt rm
$ alias -t
cat=/usr/bin/cat
rm=/usr/bin/rm
vi=/usr/bin/vi
4) Listing all tracked aliases with -pt does not output them in a
reusable format (the resulting command printed only creates a
normal alias, which is different from a tracked alias):
$ hash -r cat
$ alias -pt
alias cat=/usr/bin/cat # Expected 'alias -t cat'
5) Listing a non-existent alias with -p doesn't cause an error:
$ unalias -a
$ alias -p notanalias # No output
$ echo $?
0
$ alias notanalias
notanalias: alias not found
$ echo $?
1
$ hash -r
$ alias -pt notacommand # No output
$ echo $?
0
6) Attempting to list 256 non-existent aliases results in exit
status zero:
$ unalias -a
$ alias $(awk -v ORS= 'BEGIN { for(i=0;i<256;i++) print "x "; }')
x: alias not found
--cut error message--
$ echo $?
0
Changes:
- typeset.c: Avoid printing anything while shcomp is compiling a
script. This is needed because the alias command is run by shcomp
to prevent parsing issues.
- b_alias(): To avoid adding tracked aliases with -pt, set
tdata.aflag to '+' so that setall() and other related functions
only list tracked aliases.
- b_alias(): Set tdata.pflag to 1 so that setall() and other
functions recognize -p was passed.
- print_value(): Add support for listing specific aliases with
'alias -p'.
- setall(): To avoid any issues with zombie tracked aliases (see also
the regression tests) ignore tracked alias nodes marked with the
NV_NOALIAS attribute. This bit is set for tracked alias nodes by
the nv_rehash() function.
- setall(): For backward compatibility, continue incrementing the
exit status for each invalid alias and tracked alias passed. This
was already how alias behaved when listing aliases without -p, so
using -p shouldn't cause a change in behavior:
$ unalias -a
$ alias foo bar
foo: alias not found
bar: alias not found
$ echo $?
2
To fix bug 6, the exit status is set to one if an enforced 8-bit
exit status would be zero.
- print_namval(): Set the prefix to 'alias -t' so that listing
tracked aliases with 'alias -pt' works correctly.
- data/msg.c and include/name.h: Add an error message for when
'alias -pt' doesn't find a tracked alias.
- tests/alias.sh: Add a ton of regression tests for the bugs fixed in
this commit.
The sh_close() function fails to set errno to EBADF when passed a
negative (invalid) file descriptor. This commit fixes the issue
by setting errno if the file descriptor is a negative value
(backported from ksh93v- 2012-08-24).
This takes another step towards cleaning up the build system. We
now do not even pretend to be theoretically compatible with
pre-1989 K&R C compilers or with C++ compilers. In practice, this
had already been broken for many years due to bit rot.
Commit 46593a89 already removed the license handling enormity that
depended on proto, so now we can cleanly remove it altogether. But
we do need to leave some backwards compatibility stubs to keep the
build system compatible with older AST code; it should remain
possible to build older ksh versions with the current build system
(the bin/ and src/cmd/INIT/ directories) for testing purposes.
So as of now there is no more __MANGLE__d rubbish in your generated
header files. This is only about a quarter of a century overdue...
This commit also includes a huge amount of code cleanup to remove
thousands of unused K&R C fallbacks and other cruft, particularly
in libast. This code base should now be a little easier to
understand for people who are familiar with a modern(ish) C
standard.
ratz is now also removed; this was a standalone and simplified 2005
version of gunzip. As of 6137b99a, none of our code uses it, even
theoretically. And the real g(un)zip is now everywhere.
src/cmd/INIT/proto.c, src/cmd/INIT/ratz.c:
- Removed.
COPYRIGHT:
- Remove zlib license; this only applied to ratz.
bin/package, src/cmd/INIT/package.sh:
- Related cleanups.
- Unset LC_ALL before invoking a new shell, respecting the user's
locale again and avoiding multibyte character corruption on the
command line.
src/cmd/INIT/proto.sh:
- Add stub for backwards compatibility with Mamfiles that depend on
proto. It does nothing but pass input without modification and is
now installed as the new arch/*/bin/proto by src/cmd/INIT/Mamfile.
src/cmd/INIT/iffe.sh:
- Ignore the proto-related -e (--package) and -p (--prototyped)
options; keep parsing them for backwards compatibility.
- Trim the macros passed to every test to their standard C
versions, removing K&R C and C++ versions. These are now
considered to be for backwards compatibility only.
src/cmd/INIT/iffe.tst:
- Remove proto(1) mangling code.
By the way, iffe can be regression-tested as follows:
$ bin/package use # set up environment in a child shell
$ regress src/cmd/INIT/iffe.tst
$ exit # leave package environment
src/cmd/INIT/make.probe, src/cmd/INIT/probe.win32:
- Remove code to handle C++.
src/lib/libast/features/common:
- As in iffe.sh above, trim macros designed for compatibility with
C++ and ancient C compilers to their standard C versions and
comment that they are for backwards compatibility with AST code.
This is needed to keep all the old ast and ksh code compiling.
src/cmd/ksh93/sh/init.c,
src/cmd/ksh93/sh/name.c:
- Clarify libshell ABI compatibility function versions of macros.
A "proto workaround" comment in the original code mislead me into
thinking this had something to do with the removed proto(1), but
it's unrelated. Call the workaround macro BYPASS_MACRO instead.
src/cmd/ksh93/include/defs.h:
- sh_sigcheck() macro: allow &sh as an argument: parenthesise shp.
src/cmd/ksh93/sh/nvtype.c:
- Remove unused nv_mkstruct() function. (re: d0a5cab1)
**/features/*:
- Remove obsolete iffe 'set prototyped' option.
**/Mamfile:
- Remove all references to the ast/prototyped.h header.
- Remove all use of the proto command. Simply copy instead.
*** 850-ish source files: ***
- Remove all '#pragma prototyped' directives.
- Remove all C++ compat code conditional upon defined(__cplusplus).
- Remove all use of the _ARG_ macro, which on standard C expands to
its argument:
#define _ARG_(x) x
(on K&R C, it expanded to nothing)
- Remove all use of _BEGIN_EXTERNS_ and _END_EXTERNS_ macros (empty
on standard C; this was for C++ compatibility)
- Reduce all #if __STD_C (standard code) #else (K&R code) #endif
blocks to the standard code only, without use of the macro.
- Same for _STD_ macro which seems to have had the same function.
- Change all instances of 'Void_t' to standard 'void'.
- sh/args.c: A process substitution run in a profile script may print
its PID as if it was a command spawned with '&'. Reproducer:
$ cat /tmp/env
true >(false)
$ ENV=/tmp/env ksh
[1] 730227
$
This bug is fixed by turning off the SH_PROFILE state while running
a process substitution.
- sh/subshell.c: The SH_INTERACTIVE fix in 3525535e renders the extra
check for SH_PROFILE redundant, so it has been removed.
- tests/io.sh: Update the procsub PIDs test to also check the result
after using process substitution in a profile script.
I ended up committing versions of the fix to the master and 1.0
branches that differed only in whitespace in a few lines (no code
differences). This commit makes the whitespace identical so this
does not keep annoying me when I look at 'git diff 1.0 master'.
Reproducer: run vi in a subshell:
$ (vi)
vi opens; now press Ctrl+Z to suspend. The output is as expected:
[2] + Stopped (vi)
…but the exit status is 18 (SIGTSTP's signal number) instead of 0.
Now do:
$ fg
(vi)
$
The exit status is 18 again, vi is not resumed, and the job is
lost. You have to find vi's pid manually using ps and kill it.
Forking all non-command substitution subshells invoked from the
interactive main shell is the only reliable and effective fix I've
found. I've tried to fork the subshell conditionally in every other
remotely plausible place I can think of in fault.c and xec.c, but I
can't get anything to work properly. If anyone can get this to work
without forking as much (or at all), please do submit a patch or PR
that supersedes this fix.
At least subshells of subshells don't need to fork, so the
performance impact can be limited. Plus, it's not as if most people
need maximum speed on the interactive command line. Scripts
(including login/profile scripts) are not affected at all.
Command substitutions can be handled differently. My testing shows
that all shells except ksh93 simply block SIGTSTP (the ^Z signal)
while they run. We should do the same, so they don't need to fork.
NOTE for any backporters: the subshell.c and fault.c changes depend
on commits 35b02626 and 48ba6964 to work correctly.
src/cmd/ksh93/sh/subshell.c: sh_subshell():
- If the interactive shell state bit is on, then before executing
the subshell's code:
- for command substitutions, block SIGTSTP;
- for other subshells, fork.
- For command substitutions, release SIGTSTP if the interactive
shell state bit was on upon invoking the subshell.
src/cmd/ksh93/sh/fault.c:
- Instead of checking for a virtual subshell, check the shell's
interactive state bit to decide whether to handle SIGTSTP, as
that is only turned on in the interactive main shell.
src/cmd/ksh93/sh/main.c: sh_main():
- To avoid bugs, ignore SIGTSTP while running profile scripts.
Blocking it doesn't work because delaying it until after
sigrelease() will cause a crash. Thanks to @JohnoKing for this.
- While we're here, prevent a possible overflow of the 'beenhere'
static char variable by only incrementing it once.
Co-authored-by: Johnothan King <johnothanking@protonmail.com>
Resolves: https://github.com/ksh93/ksh/issues/390
Reproducer:
$ (sleep 1& echo done)
done
$ (eval "echo hi"; sleep 1& echo done)
hi
[1] 30587
done
No job control output should be printed for a background process
invoked from a subshell, not even after 'eval'.
The cause: sh_parse() turns on the shell's interactive state bit
(sh_state(SH_INTERACTIVE)) if the interactive shell option is on.
This is incorrect. The parser should have no involvement with shell
interactivity in principle because that's not its domain.
Not only that, the parser may need to run in a subshell, e.g. when
executing traps or 'eval' commands (as above). By definition, a
subshell can never be interactive.
We already fixed many bugs related to job control and the shell's
interactive state. Even if these two lines previously papered over
some breakage, I can't find any now after simply removing them. If
any is found later, then it'll need to be fixed properly instead.
Related: https://github.com/ksh93/ksh/issues/390
- Redirect error output from the ulimit builtin (re: 3e58851f).
- Fix the test failure for 'cd -eP' on illumos by making a directory
symlink first, then removing the symlink after cd.
- Fix the test failure for 'getconf -l' on illumos by quoting
strings with the -q option.
- astconf.c: Only quote strings if the -q option was passed.
- Improve error messages from intermittently failing types.sh tests
If the compiler is called gcc but not cc, the 64-bit detection
didn't work and $HOSTTYPE (and the arch/ subdirectory) did not get
the -64 suffix.
bin/package, src/cmd/INIT/package.sh:
- Run checkcc() before attempting to compile the program. This will
set $cc to the path to gcc if there is no 'cc' command.
- trap: use 'rm -rf' to also delete .dSYM directories (macOS).
- checkcc(): Since we're here, find clang as well.
The goal is to get rid of all compiler/linker wrapper scripts as
they are overridden by passing CC/LD and it should be possible to
select your compiler or linker without breaking the build. The
probing and feature testing system should set the appropriate flags
and macros. This makes some progress towards that.
src/lib/libast/features/standards:
- Eliminate the shotgun approach to standards macros on popular
systems where the macros we we need to set are known and
documented. The following will enable standards compliance plus
all the available extensions:
- Set no macros at all for any BSD system (excluding macOS).
- Set _DARWIN_C_SOURCE on Darwin/macOS.
- Set everything and the kitchen sink for Solaris/illumos in
a way that enables backwards compatibility with older Solaris.
This is unofficial, but following the standards(5) manual
disables a lot of basic functionality that we depend on.
- Set _GNU_SOURCE for GNU (glibc).
- Remove the covered macros from the shotgun approach fallback.
- Add a new heuristic. _POSIX_PATH_MAX and _SC_PAGESIZE are among
the basic macros disabled when you pass recommended standards
macros, killing the build, so it's good to check if they compile.
src/cmd/INIT/ar.freebsd12.amd64,
src/cmd/INIT/ar.linux.i386-64:
- Removed. May cause build failures on some systems as not all 'ar'
implementations support the U option. Plus, I can think of no
good reason to disable deterministic mode (which always creates
identical output) on 'ar' implementations that support it. See:
https://groups.google.com/g/comp.unix.shell/c/LdOD1Ya0C9E/m/U6DhgHVICwAJ
src/cmd/INIT/cc.linux.*-icc,
Removed icc wrappers. These manually source /etc/profile.d/icc.sh
but I don't think that is the build system's job. Profile scripts
should be run at login time and export variables we inherit
through the environment.
src/cmd/INIT.cc.{freebsd,linux,openbsd}*:
- Removed. Should be entirely superfluous now that the standards
feature test sets the appropriate macros.
src/cmd/INIT.cc.sol11.*:
- Removed as the standards feature test now sets the approopriate
macros. Note the Solaris build system should now simply pass CC
as normal instead of passing CC_EXPLICIT.
Inserting the _common script instead of sourcing it caused all test
failures in shcomp runs to be reported with the number of lines in
_common added.
src/cmd/ksh93/shtests:
- Only incorporate the aliases from _common; dot/source the rest of
the code as normal. Replace the first few lines with the aliases
to avoid affecting $LINENO; they are comments anyway.
With a better understanding of the code 1.5 years later, the
special-casing for IFS introduced in that commit seems like a hack.
The problem was not that the IFS node always exists but that it is
always considered to have a 'get' discipline function. Variables
with a 'get' discipline are considered set. This makes sense for
all variables except IFS.
The nv_isnull() macro is used to check if a variable is set. It
calls nv_hasget() to determine if the variable has a 'get'
discipline. So a better fix is for nv_hasget() always to return
false for IFS.
src/cmd/ksh93/bltins/test.c, src/cmd/ksh93/sh/macro.c:
- Remove special-casing for IFS.
src/cmd/ksh93/sh/nvdisc.c: nv_hasget():
- Always return false for IFS, taking local scope into account.
src/cmd/INIT/package.sh, bin/package:
- Derive the command name from $0 instead of hardcoding it.
- Remove NPROC and related code to support parallel building. This
is not supported with mamake, is unlikely to be reintroduced any
time soon, and if it ever is it will need to be done in a
different way anwyay.
- Invoke 'sed' and 'tr' directly instead of via $SED and $TR
variables. We're not building our own dynamically linked 'sed'
and 'tr' in this distribution so LD_LIBRARY_PATH is irrelevant.
If we ever do again, there are better ways to make sure the OS
standard 'sed' and 'tr' are invoked than this kludge.
- Use note() consistently to print warnings to standard error.
note() is changed to print each argument on a new line prefixed
by the command name, so arguments need to be quoted now if they
are to be shown on a single line.
- Use a new err_out() function to error out, avoiding code
repetition.
Announcing: KornShell 93u+m 1.0.0-beta.2
https://github.com/ksh93/ksh
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+. This new fork is called ksh 93u+m as a
permanent nod to its origin. We're restarting it at version 1.0. Seven
months after the first beta, the second one is ready. Please test this
second beta and report any bugs you find, or help us fix known bugs.
We're now the default ksh93 in some OS distributions, at least Debian
and Slackware! Even though we don't think it's stable release quality
yet, the consensus seems to be that 93u+m is already much better than
the last AT&T release.
Main developers: Martijn Dekker, Johnothan King, hyenias
Contributors: Andy Fiddaman, Anuradha Weeraman, Chase, Gordon Woodhull,
Govind Kamat, Harald van Dijk, Lev Kujawski, Marc Wilson, Ryan Schmidt,
Sterling Jensen
HOW TO GET IT
Please download the source code tarball from our GitHub releases page:
https://github.com/ksh93/ksh/releases
To build, follow the instructions in README.md or src/cmd/ksh93/README.
HOW TO GET INVOLVED
To report a bug, please open an issue at our GitHub page (see above).
Alternatively, email me at martijn@inlv.org with your report.
To get involved in development, read the brief policy information in
README.md and then jump right in with a pull request or email a patch.
See the TODO file in the top-level directory for a to-do list.
*** MAIN CHANGES between 1.0.0-beta.1 and 1.0.0-beta.2 ***
New features in built-in commands:
- 'cd' now supports an -e option that, when combined with -P, verifies
that $PWD is correct after changing directories; this helps detect
access permission problems. See:
https://www.austingroupbugs.net/view.php?id=253
- 'printf' now supports a -v option as in bash. This assigns formatted
output directly to variables, which is very fast and will not strip
final newline (\n) characters.
- The 'return' command, when used to return from a function, can now
return any status value in the 32-bit signed integer range, like on
zsh. However, due to a traditional Unix kernel limitation, $? is
still trimmed to its least significant 8 bits whenever leaving a
(sub)shell environment.
- 'test'/'[' now supports all the same operators as [[ (including =~,
\<, \>) except for the different 'and'/'or' operators. Note that
'test'/'[' remains deprecated due to its unfixable pitfalls;
[[ ... ]] is recommended instead.
Shell language changes:
- Several improvements were made to the --noexec shell code linter.
- Arithmetic expressions in native ksh mode no longer interpret a
number with a leading zero as octal in any context. Use 8#octalnumber
instead (e.g. 8#400 == 256). Arithmetic expressions now also behave
identically within and outside ((...)) and $((...)).
- POSIX compatibility mode fixes (only applicable with the --posix shell
option on):
- A leading zero is now consistently recognised as introducing an octal
number in all arithmetic contexts.
- $((inf)) and $((nan)) are now interpreted as regular variables.
- The '.' built-in no longer runs ksh functions and now only runs
files.
Bugs fixed:
- '.' and '..' are now once again completed by tab completion.
- If SIGINT is set to ignore, the interactive shell no longer exits on
Ctrl+C.
- ksh now builds and runs on Apple's new M1 hardware.
- The 'return' and 'exit' commands no longer risk triggering actual
signals by returning or exiting with a status > 256.
- Ksh no longer behaves badly when parsing a type definition command
('typeset -T' or 'enum') without executing it or when executing it in
a subshell. Types can now safely be defined in subshells and defined
conditionally as in 'if condition; then enum ...; fi'.
- Discipline functions, especially those applied to PS2 or .sh.tilde,
will no longer crash your shell upon being interrupted or throwing an
error.
- Fixed a bug that could corrupt output if standard output is closed
upon initialising the shell.
- Fixed a bug in the [[ ... ]] compound command: the '!' logical
negation operator now correctly negates another '!', e.g.,
[[ ! ! 1 -eq 1 ]] now returns 0/true. Note that this has always been
the case for 'test'/'['.
- Fixed SHLVL so that replacing ksh by itself (exec ksh) will not
increase it.
- Arithmetic expressions are no longer allowed to assign out-of-range
values to variables of types declared with enum.
- The 'time' keyword no longer makes the --errexit shell option
ineffective.
- Various bugs in libcmd built-in commands (those bound to the
/opt/ast/bin path by default) have been fixed.
- Various other crashing bugs have been fixed.
Fixes for the shcomp byte code compiler:
- shcomp is now able to compile scripts that define types using enum.
- shcomp now refuses to mess up your terminal by writing bytecode
to it.
*** MAIN CHANGES between ksh 93u+ 2012-08-01 and 93u+m 1.0.0-beta.1 ***
Hundreds of bugs have been fixed, including many serious/critical bugs.
This includes upstreamed patches from OpenSUSE, Red Hat, and Solaris, fixes
backported from the abandoned 93v- beta and ksh2020 fork, as well as many
new fixes from the community. See the NEWS file for more information, and
the git commit log for complete documentation of every fix. Incompatible
changes have been minimised, but not at the expense of fixing bugs. For a
list of potentially incompatible changes, see src/cmd/ksh93/COMPATIBILITY.
Though there was a "no new features, bugfixes only" policy, some new
features were found necessary, either to fix serious design flaws or to
complete functionality that was evidently intended, but not finished.
Below is a summary of these new features.
New command line editor features:
- The forward-delete and End keys are now handled as expected in the
emacs and vi built-in line editors.
- In the vi and emacs line editors, repeat count parameters can now also
be used for the arrow keys and the forward-delete key. E.g., in emacs
mode, <ESC> 7 <left-arrow> will now move the cursor seven positions to
the left. In vi control mode, this would be entered as: 7 <left-arrow>.
New shell language features:
- The &>file redirection shorthand (for >file 2>&1) is now available for
all scripts and interactive sessions and not only for profile/login
scripts, bringing ksh 93u+m in line with mksh, bash, and zsh.
- File name generation (a.k.a. pathname expansion, a.k.a. globbing) now
never matches the special navigational names '.' (current directory)
and '..' (parent directory). This change makes a pattern like .*
useful; it now matches all hidden files (dotfiles) in the current
directory, without the harmful inclusion of '.' and '..'.
- Tilde expansion can now be extended or modified by defining a
.sh.tilde.get or .sh.tilde.set discipline function. This replaces a
2004 undocumented attempt to add this functionality via a .sh.tilde
command, which never worked and crashed the shell. See the manual for
details on the new method.
New features in built-in commands:
- Usage error messages now show the --help/--man self-documentation options.
- Path-bound built-ins (such as /opt/ast/bin/cat) can now be executed by
invoking the canonical path, so the following will now work as expected:
$ /opt/ast/bin/cat --version
version cat (AT&T Research) 2012-05-31
- 'command -x' now looks for external commands only, skipping built-ins.
In addition, its xargs-like functionality no longer freezes the shell on
Linux and macOS, making it effectively a new feature on these systems.
- 'redirect' now checks if all arguments are valid redirections before
performing them. If an error occurs, it issues an error message instead
of terminating the shell.
- 'suspend' now refuses to suspend a login shell, as there is probably no
parent shell to return to and the login session would freeze.
- 'times' now gives high precision output in a POSIX compliant format.
- 'typeset' now gives an informative error message if an incompatible
combination of options is given.
- 'whence -v/-a' now reports the location of autoloadable functions.
New features in shell options:
- A new --globcasedetect shell option is added on OSs where we can
check for a case-insensitive file system (currently Windows/Cygwin,
macOS, Linux and QNX 7.0+). When this option is turned on, file name
generation (globbing), as well as file name tab completion on
interactive shells, automatically become case-insensitive on file
systems where the difference between upper and lower case is ignored
for file names. 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.
- A new --nobackslashctrl shell option disables the special escaping
behaviour of the backslash character in the emacs and vi built-in
editors. Particularly in the emacs editor, this makes it much easier to
go backward, insert a forgotten backslash into a command, and then
continue editing without having your next cursor key replace your
backslash with garbage. Note that Ctrl+V (or whatever other character
was set using 'stty lnext') always escapes all control characters in
either editing mode.
- A new --posix shell option has been added to ksh 93u+m that makes the
ksh language more compatible with other shells by following the POSIX
standard more closely. See the manual page for details. It is enabled by
default if ksh is invoked as sh, otherwise it is disabled by default.
- Enhancement to -G/--globstar: symbolic links to directories are now
followed if they match a normal (non-**) glob pattern. For example, if
'/lnk' is a symlink to a directory, '/lnk/**' and '/l?k/**' now work as
you would expect.
Strings compared in [[ with the > and < operators should be compared
lexically. This does not work when the strings are single digits, as
the parser interprets it as a syntax error:
$ [[ 10<2 ]] # 10 lexically sorts before 2
$ echo $?
0
$ [[ 1<2 ]]
/usr/bin/ksh: syntax error: `<' unexpected
$ echo $?
3
src/cmd/ksh93/sh/lex.c:
- Don't interpret numbers next to > and < as a redirection while
inside of [[. This bugfix was backported from ksh93v- 2014-06-25.
src/cmd/ksh93/tests/bracket.sh:
- Add regression tests for the > and < operators.
New version. I'm pretty sure the problems that forced me to revert
it earlier are fixed.
This commit mitigates the effects of the hack explained in the
referenced commit so that dummy built-in command nodes added by the
parser for declaration/assignment purposes do not leak out into the
execution level, except in a relatively harmless corner case.
Something like
if false; then
typeset -T Foo_t=(integer -i bar)
fi
will no longer leave a broken dummy Foo_t declaration command. The
same applies to declaration commands created with enum.
The corner case remaining is:
$ ksh -c 'false && enum E_t=(a b c); E_t -a x=(b b a c)'
ksh: E_t: not found
Since the 'enum' command is not executed, this should have thrown
a syntax error on the 'E_t -a' declaration:
ksh: syntax error at line 1: `(' unexpected
This is because the -c script is parsed entirely before being
executed, so E_t is recognised as a declaration built-in at parse
time. However, the 'not found' error shows that it was successfully
eliminated at execution time, so the inconsistent state will no
longer persist.
This fix now allows another fix to be effective as well: since
built-ins do not know about virtual subshells, fork a virtual
subshell into a real subshell before adding any built-ins.
src/cmd/ksh93/sh/parse.c:
- Add a pair of functions, dcl_hactivate() and dcl_dehacktivate(),
that (de)activate an internal declaration built-ins tree into
which check_typedef() can pre-add dummy type declaration command
nodes. A viewpath from the main built-ins tree to this internal
tree is added, unifying the two for search purposes and causing
new nodes to be added to the internal tree. When parsing is done,
we close that viewpath. This hides those pre-added nodes at
execution time. Since the parser is sometimes called recursively
(e.g. for command substitutions), keep track of this and only
activate and deactivate at the first level.
(Fixed compared to previous version of this commit: calling
dcl_dehacktivate() when the recursion level is already zero is
now a harmless no-op. Since this only occurs in error handling
conditions, who cares.)
- We also need to catch errors. This is done by setting libast's
error_info.exit variable to a dcl_exit() function that tidies up
and then passes control to the original (usually sh_exit()).
(Fixed compared to previous version of this commit: dcl_exit()
immediately deactivates the hack, no matter the recursion level,
and restores the regular sh_exit(). This is the right thing to
do when we're in the process of erroring out.)
- sh_cmd(): This is the most central function in the parser. You'd
think it was sh_parse(), but $(modern)-form command substitutions
use sh_dolparen() instead. Both call sh_cmd(). So let's simply
add a dcl_hacktivate() call at the beginning and a
dcl_deactivate() call at the end.
- assign(): This function calls path_search(), which among many
other things executes an FPATH search, which may execute
arbitrary code at parse time (!!!). So, regardless of recursion
level, forcibly dehacktivate() to avoid those ugly parser side
effects returning in that context.
src/cmd/ksh93/bltins/enum.c: b_enum():
- Fork a virtual subshell before adding a built-in.
src/cmd/ksh93/sh/xec.c: sh_exec():
- Fork a virtual subshell when detecting typeset's -T option.
Improves fix to https://github.com/ksh93/ksh/issues/256
The killpg(getpgrp(),SIGINT) call added to ed_getchar() in that
commit caused the interactive shell to exit on ^C even if SIGINT is
being ignored. We cannot revert or remove that call without
breaking job control. This commit applies a new fix instead.
Reproducers fixed by this commit:
SIGINT ignored by child:
$ PS1='childshell$ ' ksh
childshell$ trap '' INT
childshell$ (press Ctrl+C)
$
SIGINT ignored by parent:
$ (trap '' INT; ENV=/./dev/null PS1='childshell$ ' ksh)
childshell$ (press Ctrl+C)
$
SIGINT ignored by parent, trapped in child:
$ (trap '' INT; ENV=/./dev/null PS1='childshell$ ' ksh)
childshell$ trap 'echo test' INT
childshell$ (press Ctrl+C)
$
I've experimentally determined that, under these conditions, the
SFIO stream error state is set to 256 == 0400 == SH_EXITSIG.
src/cmd/ksh93/sh/main.c: exfile():
- On EOF or error, do not return (exiting the shell) if the shell
state is interactive and if sferror(iop)==SH_EXITSIG.
- Refactor that block a little to make the new check fit in nicely.
src/cmd/ksh93/tests/pty.sh:
- Test the above three reproducers.
Fixes: https://github.com/ksh93/ksh/issues/343
Note that this is only about the /opt/ast/bin built-in commands,
not about the regular pathless builtins such as printf.
To use these, either add /opt/ast/bin to your $PATH or use a
command like 'builtin cp'. As usual, --man provides info.
Removed as defaults for lack of convincing advantages over the OS's
external commands:
- chmod, cmp, head, logname, mkdir, sync, uname, wc
Remain as useful defaults:
- basename, cat, cut, dirname. These are commonly used in
performance-sensitive code paths in scripts and having them as
built-ins can be good for performance.
- getconf: This is the only interface to some libast internals that
is available to ksh. It's also has better functionality than most
OS-shipped 'getconf' commands, e.g., it can list and query all
the configuration values.
Added as defaults:
- cp, ln, mv: Having these built in can speed up scripts that
manage files. Also the AST versions have extended functionality
(see cp --man, etc.).
- mktemp: External mktemp commands vary too widely and are
incompatible, but it's important that scripts can securely make
temporary files, so it's good to ship a known interface to this
functionality.
As a result, the statically linked ksh binary is very slightly
smaller than before.
Resolves: https://github.com/ksh93/ksh/issues/349
The pty tests tests the interactive shell. Therefore, running them
through the script compiler is a waste of time.
Not only that, it is reported that the pty tests intermittently
fail with shcomp on some systems. This is not worth trying to fix.
src/cmd/ksh93/tests/shtests:
- Only run pty.sh with shcomp if -c/--compile was explicitly
specified.
- Document the change.
Welcome to AT&T engineering practices in action: a fix in one thing
breaks a completely unreleated thing, but only in very specific
and inscrutable circumstances.
Commit ffe84ee7 introduced a regression test failure in types.sh:
test types begins at 2021-12-14+23:57:35
types.sh[130]: z.r.s should be z.r.x
test types failed at 2021-12-14+23:57:35 with exit code 1 [ 86 tests 1 error ]
test types(C.UTF-8) begins at 2021-12-14+23:57:35
test types(C.UTF-8) passed at 2021-12-14+23:57:35 [ 86 tests 0 errors ]
test types(shcomp) begins at 2021-12-14+23:57:35
test types(shcomp) passed at 2021-12-14+23:57:35 [ 86 tests 0 errors ]
Only enough, I've *only* found this regression on the GitHub CI
runner. I've tried it on three different regular Linux systems and
it occurs on none of them, nor on macOS.
Another odd thing: it only fails on the first of those three test
runs. But my experiments show it fails very consistently.
Through a process of systematic elimination in a test branch, I've
found that the failure is triggered by the change to using a
separate stack in the regex code. All the other changes are fine.
Using a separate stack improves the robustness of the regex code,
but it apparently exposes some breakage in how the very dodgy
'typeset -T' code is handling the stack, which was being masked by
sharing a stack with it. Or at least that seems like the most
plausible explanation to me right now.
So, until that breakage can be traced and fixed, the regex code now
shares the main stack with everything else again for the time being.
_____
Just to record this: by adding a couple of debug lines:
typeset -p z | sed 's/^/[DEBUG] /'
printf '[DEBUG] %s\n' "${z.r.s}" "${z.r.x}"
the symptom reveals itself more clearly on the GitHub runner:
test types begins at 2021-12-15+17:25:57
[DEBUG] Y_t z=(X_t r=(x=foo;y=bam;s=''))
[DEBUG]
[DEBUG] foo
types.sh[132]: z.r.s should be z.r.x
test types failed at 2021-12-15+17:25:57 with exit code 1 [ 86 tests 1 error ]
test types(C.UTF-8) begins at 2021-12-15+17:25:57
[DEBUG] Y_t z=(X_t r=(x=foo;y=bam;s=foo))
[DEBUG] foo
[DEBUG] foo
test types(C.UTF-8) passed at 2021-12-15+17:25:57 [ 86 tests 0 errors ]
test types(shcomp) begins at 2021-12-15+17:25:57
[DEBUG] Y_t z=(X_t r=(x=foo;y=bam;s=foo))
[DEBUG] foo
[DEBUG] foo
test types(shcomp) passed at 2021-12-15+17:25:57 [ 86 tests 0 errors ]
Yes, we're finally abandoning the old Bourne shell so we can
use sane $(command substitutions) and the like. POSIX sh (with
tolerance for shell bugs) is very highly portable these days.
Even Solaris 10 has a POSIX shell, though not as /bin/sh.
bin/package, src/cmd/INIT/package.sh:
- Be nice: if we're on an obsolete or broken shell, try hard to
escape to a good one. This should preserve the possibility to
just run 'bin/package make' via ancient /bin/sh on Solaris 10.
- Note: zsh without sh emulation is considered broken because
$path, which we use, is linked to $PATH. You have to run it via
a symlink named sh or via 'zsh --emulate sh' to disable this.
Enabling emulation mode after initialisation will not work.
- More self-documentation cleanups and updates.
- Regenerate the text-only fallback version of the self-doc.
- Remove flat view functionality (no arch directory); it may have
been broken for some time, but quite frankly I could not care
less. It's yet more featuritis. Building in arch/ is fine.
There are two main changes:
1. The regex code now creates and uses its own stack (env->mst)
instead of using the shared standard stack (stkstd). That seems
likely to be a good thing.
2. Missing mbinit() calls were inserted. The 93v- code uses a
completely different multibyte characters API, so these needed
to be translated back to the older API. But, as mbinit() is no
longer a no-op as of 300cd199, these calls do stop things from
breaking if a previous operation is interrupted mid-character.
I think there might be a couple of off-by-one errors fixed as well,
as there are two instances of this change:
- while ((index += skip[buf[index]]) < mid);
+ while (index < mid)
+ index += skip[buf[index]];
In the referenced commit message I neglected to mention that, when
doing bin/package make, we're now running 'tee' in the background
again and the building job in the foreground, as opposed to the
other way around. Foreground jobs are more reliably interruptable.
But that reintroduced the problem fixed in 5b8d29d3. Now I don't
know what I was thinking then -- the obvious fix is to add a 'wait'
command, allowing 'tee' to catch up before returning to the prompt.
This reduces the bin/package script by more than half!
bin/package, src/cmd/INIT/package.sh:
- Remove obsolete and unused package commands: admin, contents,
license, list, remote, regress, setup, update, verify, write.
- Remove associated documentation.
- Replace install command with a dummy. It'll come back when we
reintroduce the building of dynamic libaries.
- Update the test command to run the regression tests properly
and capture the output in arch/*/lib/package/gen/tests.out, as
documented. Arguments are simply passed to bin/shtests.
src/cmd/INIT/{ditto.sh,hurl.sh,release.c}:
- Removed. These were support scripts for some of the removed
package commands.
src/cmd/ksh93/tests/pty.sh:
- Avoid failure when capturing output via 'bin/package test' by
redirecting standard error to /dev/tty when running the tests.
This bug was first reported at <https://www.illumos.org/issues/3782>.
The chown builtin when used on illumos can fail with different error
messages after running the same command twice:
$ touch /tmp/x
$ /opt/ast/bin/chown -h 433:434 /tmp/px
chown: /tmp/x: cannot change owner and group [Not owner]
$ /opt/ast/bin/chown -h 433:434 /tmp/px
chown: /tmp/x: cannot change owner and group [Invalid argument]
The error messages differ because the libast struid and strgid
functions will return -2 if the same nonexistent ID is used twice.
The fix for this bug has been ported from here:
https://github.com/illumos/illumos-gate/commit/4162633a7c5961f388fd
src/lib/libcmd/chgrp.c:
- Remove NOID macro and check for a < 0 error status instead.
This is different from the Illumos fix at
<https://github.com/illumos/illumos-gate/commit/4162633a7c59>
which added another macro.
src/lib/libast/man/{strgid,struid}.3:
- Correct errors in the strgid and struid documentation.
- Document that the strgid and struid functions will return -2 if
the same invalid name is used twice.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
The standards macros consistency fix for iffe exposed breakage on
illumos: the standards flags aren't set properly. Back in 580ff616,
I set _XPG6 from features/common, which is the wrong place; the
correct place is features/standards -- especially now that iffe
uses its results.
In addition, to get header declarations that aren't somehow in
conflict with themselves on illumos, don't result in "implicit
function declaration" warnings, and expose all the functionality,
we need to define *all* the _XPG[4-7] macros *and* __EXTENSIONS__
*and* _XOPEN_SOURCE. Welp. Thankfully, that's just fine with
Solaris, too.
Thanks to @JohnoKing for the heads-up.
Running 'bin/package environment' should only show what will happen
during the build process, but in it's current state the feature has
some bugs:
1. Errors can occur relating to the failed creation of files and a
failed attempt to change the directory. Various errors from
'bin/package environment make' and 'bin/package environment make
CC=tcc':
bin/package[5632]: cd: /home/johno/GitRepos/KornShell/ksh/arch/linux.i386-64/lib/package/gen: [No such file or directory]
bin/package: line 5869: /home/johno/GitRepos/KornShell/ksh/arch/linux.i386-64/lib/package/gen/CC: cannot create [No such file or directory]
bin/package: line 5869: /home/johno/GitRepos/KornShell/ksh/arch/linux.i386-64/lib/package/gen/CCFLAGS: cannot create [No such file or directory]
bin/package: line 5869: /home/johno/GitRepos/KornShell/ksh/arch/linux.i386-64/lib/package/gen/CCLDFLAGS: cannot create [No such file or directory]
bin/package: line 5869: /home/johno/GitRepos/KornShell/ksh/arch/linux.i386-64/lib/package/gen/LDFLAGS: cannot create [No such file or directory]
bin/package: line 5869: /home/johno/GitRepos/KornShell/ksh/arch/linux.i386-64/lib/package/gen/KSH_RELFLAGS: cannot create [No such file or directory]
bin/package[5888]: /home/johno/GitRepos/KornShell/ksh/arch/linux.i386-64/lib/package/gen/host: cannot create [No such file or directory]
2. The package script may in some scenarios create a temporary file
at the root of the repository, such as 'pkg77213.c'.
bin/package, src/cmd/INIT/package.sh:
- Avoid creating files or changing the directory while the
environment qualifier is on (this also affects the debug
qualifier). Part of this fix is based on a patch from Marcin
Cieślak[*], with other fixes applied for similar problems the
environment qualifier had.
I'm now taking another small step towards extricating this build
system from the long-dead AT&T AST universe.
This commit modifies/reduces the tool called proto. AT&T used proto
for two purposes:
1. To convert ANSI C code to a form compatible with ancient
(pre-ANSI) K&R C compilers using extremely complex macro
voodo. It was similarly capable of translating to C++.
Theoretically, this entire code base should compile on
anything from a 1980s K&R C compiler to a modern C++ compiler.
In practice, given the massive amount of bit rot we inherited,
I am 99.9% sure that this has been broken for many years.
2. To automagically insert license comments into source files
based on an extremely complicated license database system.
(In all-too-typical AT&T fashion, this second function of
proto is completely unrelated to the first.)
Function 2 has now been removed because, unlike the AT&T legal
department, I don't think it's worth going to unspeakably extreme
lengths to avoid maintaining license information in source code
files by hand.
In the process, proto.c was cleaned up to look halfway like actual
C code, but it's still processed code: most macros have been
expanded to their numeric value, all comments were stripped, etc.
So don't expect to understand this code. The actual source code is
in these two directories in the ast-open-history repo:
https://github.com/ksh93/ast-open-history/tree/master/src/cmd/protohttps://github.com/ksh93/ast-open-history/tree/master/src/lib/libpp
Meanwhile, nobody wants to compile ksh with a pre-ANSI K&R C
compiler in 2021 -- and there's no good reason to be compatible
with C++ because standard C compilers are universally available.
So, proto will go away when I manage to figure out how to pry it
loose from the innards of this build system.
src/lib/libast/port/astlicense.c:
- Removed. This is al the license handling code that was
incorporated in proto.c in stripped form. It was not used
anywhere else, and the environment where it was useful is gone.
src/cmd/INIT/proto.c:
- Cleanup to make this halfway maintainable: indentation, huge
blocks of empty lines, #line directives, etc.
- Delete all the code corresponding to astlicense.c. This was
actually easy as it was in a discrete block.
- proto(), pppopen(): Remove 'license'/'notice' and 'options'
arguments.
- main(): Remove processing of -l (license) and -o (license
options) flags.
**/Mamfile:
- Update all the proto invocations to remove the -l and -o flags.
bin/package, src/cmd/INIT/package.sh:
- Delete the 'copyright' command, which used the -l and -o
options to tell proto to extract copyright information from
*.lic/*.def files in lib/package.
COPYRIGHT:
- Added. This has the information from 'bin/package copyright', with
the copyright years corrected to plausible values as the AST code
used the current year (2021) for all of them. It adds ksh 93u+m
copyright and contributor information at the top as well.
(Yes, some of the lines in the old non-AT&T copyright notices
are clipped. This is the actual output of the 'bin/package
copyright' command as generated by 'proto' in the AST
distribution. For all that extreme complexity, they couldn't even
reproduce the notices correctly. But it's officially sanctioned
by AT&T in exactly this form, so there you have it.)
lib/package/**:
- Removed. All these files are now obsolete and redundant.
This commit fixes an issue with how ksh was obtaining the value of
NGROUPS_MAX. On some systems this setting can be changed (e.g., on
illumos adding 'set ngroups_max=32' to /etc/system then rebooting
changes NGROUPS_MAX from 16 to 32). Ksh was using NGROUPS_MAX with
the assumption it's a static value, which could cause issues on
systems where it isn't static. This bugfix is inspired by the one
from <https://github.com/lkujaw/ast/commit/b1362c3a5>, although it
has been expanded a bit to account for OPEN_MAX as well.
src/cmd/ksh93/sh/init.c, src/lib/libcmd/fds.c:
- Rename the getconf() macro to astconf_long() and move it to ast.h
to prevent redundancy. Other sections of the code have been
modified to use this macro for astconf() to account for
dynamic settings.
- An equivalent macro for unsigned long values (astconf_ulong) has
been added.
- Prefer sysconf(3) where available. It has better performance as it
returns a numeric value directly instead of via string
conversion.
- The astconf_long and astconf_ulong macros have been documented in
the ast(3) man page.
Turns out there is a bona fide, honest-to-goodness use case for
matching '.' and '..' in globbing after all. It's when globbing is
used as the backend mechanism for file name completion in
interactive shell editors. A tab invisibly adds a * at the end of
the word to the left of your cursor and the resulting pattern is
expanded. In 5312a59d, this broke for '.' and '..'.
Typing '.' followed by two tabs should result in a menu that
includes './' and '../'. Typing '..' followed by a tab should
result in '../', (or a menu that includes it if there are files
with names starting with '..'). This is the behaviour in 93u+ and
we should maintain this.
To restore this functionality without reintroducing the harmful
behaviour fixed in the referenced commits, we should special-case
this, allowing '.' and '..' to match only for file name completion.
src/lib/libast/include/glob.h:
- Fix an inaccurate comment: the GLOB_COMPLETE flag is used for
command completion, not file name completion. This is very clear
from reading the path_expand() function in sh/expand.c.
- Add new GLOB_FCOMPLETE flag for file name completion.
src/lib/libast/misc/glob.c:
- Adapt flags mask to fit the new flag.
- glob_dir(): If GLOB_FCOMPLETE is passed, allow '.' and '..' to
match even if expanded from a pattern.
- Clarify the fix from aad74597 with an extended comment based on
<https://github.com/ksh93/ksh/issues/146#issuecomment-790991990>.
src/cmd/ksh93/sh/expand.c: path_expand():
- If we're in the SH_FCOMPLETE (file name completion) state, then
pass the new GLOB_FCOMPLETE flag to AST glob(3).
Fixes: https://github.com/ksh93/ksh/issues/372
Thanks to @fbrau for the bug report.
This commit adds onto <https://github.com/ksh93/ksh/pull/353> by porting
over two additional improvements to the shell linter:
1) The changes in the aforementioned pull request were merged into
illumos-gate with an additional change.[*] The illumos revision of
the patch improved the warning for (( $foo = $? )) to specify '$foo'
causes the warning.[**] Example:
$ ksh -n -c '(( $? != $bar ))'
ksh: warning: line 1: in '(( $? != $bar ))', using '$' as in '$bar' is slower and can introduce rounding errors
While I was porting the illumos patch I did notice one problem. The
string it uses from paramsub() skips over the initial '{' in
'${var}', resulting in the warning printing '$var}' instead:
$ ksh -n -c '(( ${.sh.pid} != $$ ))'
... in '(( ${.sh.pid} != $$ ))', using '$' as in '$.sh.pid}' is slower ...
This was fixed by including the missing '{' in the string returned by
paramsub for ${var} variables.
2) In ksh93v-, parsing x=$((expr)) with the shell linter will cause ksh
to warn the user x=$((expr)) is slower than ((x=expr)). This
improvement has been backported with a modified warning:
# Result from this commit
$ ksh -n -c 'x=$((1 + 2))'
ksh: warning: line 1: x=$((1 + 2)) is slower than ((x=1 + 2))
# Result from ksh93v-
$ ksh93v -n -c 'x=$((1 + 2))'
ksh93v: warning: line 1: ((x=1 + 2)) is more efficient than x=$((1 + 2))
Minor note: the ksh93v- patch had an invalid use of memcmp; this
version of the patch uses strncmp instead.
References:
be548e87bchttps://code.illumos.org/c/illumos-gate/+/1834/comment/65722363_22fdf8e7/
The "fd is first arg to poll()" and "fd is second arg to poll()" tests
use write() but don't include the system header in which that function
is declared, leading to "error: implicit declaration of function 'write'
is invalid in C99'" when trying to compile the test. By including the
header, the test can now compile and run as intended.
The "mmap is worth using" test uses memcpy but doesn't include the
system header in which that function is declared, leading to
"error: implicitly declaring library function 'memcpy'" when trying
to compile the test. By including the header, the test can now
compile and run as intended.
On macOS, the result is still negative. The test seems to time
using mmap and another method and only picks mmap if it's faster.
Editing the test to print out timing information on a few runs, I
see that mmap is 2–3✕ slower than the other method:
$ for i in $(seq 1 5); do ./mmap_worth_using; done
/* mmtm=11 rdtm=3 */
/* 4*mmtm=44 3*rdtm=9 */
/* 4*mmtm=44 5*rdtm=15 */
/* mmtm=9 rdtm=5 */
/* 4*mmtm=36 3*rdtm=15 */
/* 4*mmtm=36 5*rdtm=25 */
/* mmtm=10 rdtm=4 */
/* 4*mmtm=40 3*rdtm=12 */
/* 4*mmtm=40 5*rdtm=20 */
/* mmtm=12 rdtm=4 */
/* 4*mmtm=48 3*rdtm=12 */
/* 4*mmtm=48 5*rdtm=20 */
/* mmtm=12 rdtm=4 */
/* 4*mmtm=48 3*rdtm=12 */
/* 4*mmtm=48 5*rdtm=20 */
If you passed CC=/some/compiler, the build broke on macOS because the
cc.darwin compiler wrapper wasn't used. Among other things, this
wrapper adds a -D_lib_memccpy flag, defining _lib_memccpy as 1
during the build. That was used to override a false negative result
of the lib_memccpy feature test. This commit fixes that feature
test instead, so it correctly returns positive on macOS.
Thanks to Ryan Smith (@ryandesign) for the bug report and for the
fix to the lib_memccpy test.
src/lib/libast/features/lib:
- Fix the lib_memccpy feature test. It was checking the result of
mmap(2) incorrectly, resulting in the test crashing on macOS.
Failure does not return NULL, it returns MAP_FAILED which is
usually -1.
src/cmd/INIT/cc.darwin*:
- Removed. Any other flags in these wrappers are either related to
building dynamic libraries, which is not currently supported, or
were determined to be unnecessary. See the GitHub issue for
discussion. This now makes it possible to pass `CC` to use any
compiler you like on the Mac. Notes:
- Apple's -D_ast_int8_t=int64_t is a no-op; another AST feature
test already defines _ast_int8_t a 64-bit integer type, even on
32-bit systems (on which it is defined as 'long long').
- The -search_paths_first linker flag is the default since 2010.
But even on my museum-grade Power Mac G5 with Mac OS X 10.3
(from 2004), it builds and runs just fine without.
- DCLK_TCK=100 is a no-op as even that ancient Mac system already
defines it as 100. Plus, it's not even actually used.
If a need is found for any of these, please report this in a new
issue so I can special-case it elsewhere in the code.
Resolves: https://github.com/ksh93/ksh/issues/373
*** Crash 1: ***
ksh crashed if the PS1 prompt contains one or more command
substitutions and you enter a multi-line command substitution
on the command line, then interrupt while on the PS2 prompt.
$ ENV=/./dev/null /usr/local/bin/ksh -o emacs
$ PS1='$(echo foo) $(echo bar) $(echo baz) ! % '
foo bar baz 16999 % echo $(
> true <-- here, press Ctrl+C instead of Return
Memory fault
The crash occurred due to a corrupted lexer state while trying to
display the PS1 prompt.
Analysis: My fix for the crashing bug with Ctrl+C in commit
3023d53b is incorrect and only worked accidentally. sh_fault() is
not the right place to reset the lexer state because, when we press
Ctrl+C on a PS2 prompt, ksh had been waiting for input to finish
lexing a multi-line command, so sh_lex() and other lexer functions
are on the function call stack and will be returned to.
src/cmd/ksh93/sh/fault.c: sh_fault():
- Remove incorrect SIGINT fix.
src/cmd/ksh93/sh/io.c: io_prompt():
- Reset the lexer state immediately before printing every PS1
prompt. Even in situations where this is redundant it should be
perfectly safe, the overhead is negligible, and it resolves this
crash. It may pre-empt other problems as well.
*** Crash 2: ***
If an INT trap is set, and you start entering a multi-line command
substitution, then press Ctrl+C on the PS2 prompt to trigger the
crash, the lexer state is corrupted because the lexer is invoked to
eval the trap action. A crash then occurs on entering the final ')'
of the command substitution.
$ trap 'echo TRAPPED' INT
$ echo $(
> trueTRAPPED <-- press Ctrl+C to output "TRAPPED"
> )
Memory fault
Technically, as SIGINT is trapped, it should not interrupt, so ksh
should execute the trap, then continue with the PS2 prompt to let
the user finish inputting the command. But I have been unsuccessful
in many different attempts to make this work properly. I managed to
get multi-line command substitutions to lex correctly by saving and
restoring the lexer state, but command substitutions were still
corrupted at the parser and/or execution level and I have not
managed to trace the cause of that.
My testing showed that all other shells interrupt the PS2 prompt
and return to PS1 when the user presses Ctrl+C, even if SIGINT is
trapped. I think that is a reasonable alternative, and it is
something I managed to make work.
src/cmd/ksh93/sh/fault.c: sh_chktrap():
- Immediately after invoking sh_trap() to run a trap action, check
if we're in a PS2 prompt (sh.nextprompt == 2). If so, assume the
lexer state is now overwritten. Closing the fcin stream with
fcclose() seems to reliably force the lexer to stop doing
anything else. Then we can just reset the prompt to PS1 and
invoke sh_exit() to start new command line, which will now reset
the lexer state as per above.
ksh crashed if you pressed Ctrl+C or Ctrl+D on a PS2 prompt while
you haven't finished entering a $(command substitution). It
corrupts subsequent command substitutions. Sometimes the situation
recovers, sometimes the shell crashes.
Simple crash reproducer:
$ PS1="\$(echo foo) \$(echo bar) \$(echo baz) > "
foo bar baz > echo $( <-- now press Ctrl+D
> ksh: syntax error: `(' unmatched
Memory fault
The same happens with Ctrl+C, minus the syntax error message.
The problem is that the lexer state becomes inconsistent when the
lexer is interrupted in the middle of reading a command
substitution of the form $( ... ). This is tracked in the
'lexd.dolparen' variable in the lexer state struct.
Resetting that variable is sufficient to fix this issue. However,
in this commit I prefer to just reinitialise the lexer state
completely to pre-empt any other possible issues. Whether there was
a syntax error or the user pressed Ctrl+C, we just interrupted all
lexing and parsing, so the lexer *should* restart from scratch.
src/cmd/ksh93/sh/fault.c: sh_fault():
- If the shell is in an interactive state (e.g. not a subshell) and
SIGINT was received, reinitialise the lexer state. This fixes the
crash with Ctrl+C.
src/cmd/ksh93/sh/lex.c: sh_syntax():
- When handling a syntax error, reset the lexer state. This fixes
the crash with Ctrl+D.
NEWS:
- Also add the forgotten item for the previous fix (re: 2322f939).
This reverts c0334e32, thereby restoring 936a1939.
After the fixes in 0a343244 and a2bc49be, the tilde expansion
disciplines work nicely, so they can come back to the 1.0 branch.
This should fix various crashes that remain, at least:
* when running a PS2 discipline at parse time
* when pressing Ctrl+C on a PS2 prompt
* when a special builtin within a discipline throws an error within
a virtual subshell
src/cmd/ksh93/sh/nvdisc.c:
- In both assign() which handles .set disciplines and lookup()
which handles .get disciplines, to stop errors in discipline
functions from wreaking havoc:
- Save, reinitialise and restore the lexer state in case the
discipline is run at parse time. This happens with PS2; I'm not
currently aware of other contexts but that doesn't mean there
aren't any or that there won't be any. Plus, I determined by
experimenting that doing this here seems to be the only way to
make it work reliably. Thankfully the overhead is low.
- Check the topfd redirection state and run sh_iorestore() if
needed. Without this, if a special builtin with a redirection
throws an error in a discipline function, its redirection(s)
remain permanent. For example, 'trap --bad-option 2>/dev/null'
in a PS2.get() discipline would kill standard error, including
all your prompts.
src/cmd/ksh93/sh/io.c: io_prompt():
- Before getting the value of the PS2 prompt, save the stack state
and restore it after. This stops a PS2.get discipline function
from corrupting a command substitution that the user is typing.
Doing this in assign()/lookup() is ineffective, so do it here.
Fixes: https://github.com/ksh93/ksh/issues/347
- tests/basic.sh: Fix a regression test that was failing under dtksh by
allowing the error message to name ksh 'lt-dtksh'. Additionally, fix
the test's inaccurate failure message (a version string is not what
the regression test expects).
- test/builtins.sh: Exclude the expr builtin from the unrecognized
options test because it's incompatible. Additionally, put the
unrecognized options test inside of a function to ensure that it works
with the future local builtin (https://github.com/ksh93/ksh/issues/123).
- tests/io.sh: The long seek test may fail to seek past the 2 GiB
boundary on 32-bit systems, so only allow it to run on 64-bit.
References:
3222ac2b59/f/ksh-1.0.0-beta.1-regre-tests.patcha5c692e1bd
- tests/substring.sh: Add a regression test for the ${.sh.match}
crashing bug fixed in commit 1bf1d2f8.
src/cmd/ksh93/sh/Mamfile:
- For edit/edit.c, add include/shlex.h (re: f99ce517).
- For sh/shcomp.c, add include/{path,terminal}.h (re: 141fa68e).
Thanks to @JohnoKing for flagging these up.
Once upon a time it might have been possible to build certain parts
of ksh, such as the emacs and vi editors and possibly even the
name/value library (nval(3)) as independent libraries. But given
the depressing amount of bit rot in the code that we inherited, I
am certain that disabling either of these macros had been resulting
in a broken build for many years before AT&T abandoned this code
base. These are certainly not going to be useful now.
Meanwhile the KSHELL macro got in the way of me today, because the
Mamfile did not define it for all the .c files, but some headers
declared some functionality conditionally upon that macro. So
including <io.h> in, e.g., nvdisc.c did not declare the same
functions as including that header in files with KSHELL defined.
This inconsistency is now gone as well, for various files.
I'm currently working on making it possible once again to build
libshell as a dynamic library; that should be good enough. And that
never involved disabling either of these macros.
The head and tail builtins don't correctly handle files that lack
newlines[*]:
$ print -n foo > /tmp/bar
$ /opt/ast/bin/head -1 /tmp/bar # No output
$ print -n 'foo\nbar' > /tmp/bar
$ /opt/ast/bin/tail -1 /tmp/bar
foo
bar$
This commit backports the required changes from ksh93v- to handle files
without a newline in the head and tail builtins. (Also note that the
required fix to sfmove was already backported in commit 1bd06207.)
src/lib/libcmd/{head,tail}.c:
- Backport the relevant ksh93v- code for handling files
without newlines.
src/cmd/ksh93/tests/builtins.sh:
- Add a few regression tests for using 'head -1' and 'tail -1' on a file
missing and ending newline.
[*]: https://www.illumos.org/issues/4149
List of changes:
- Fixed some -Wuninitialized warnings and removed some unused variables.
- Removed the unused extern for B_login (re: d8eba9d1).
- The libcmd builtins and the vmalloc memfatal function now handle
memory errors with 'ERROR_SYSTEM|ERROR_PANIC' for consistency with how
ksh itself handles out of memory errors.
- Added usage of UNREACHABLE() where it was missing from error handling.
- Extend many variables from short to int to prevent overflows (most
variables involve file descriptors).
- Backported a ksh2020 patch to fix unused value Coverity issues
(https://github.com/att/ast/pull/740).
- Note in src/cmd/ksh93/README that ksh compiles with Cygwin on
Windows 10 and Windows 11, albeit with many test failures.
- Add comments to detail some sections of code. Extensive list of
commits related to this change:
ca2443b5, 7e7f1372, 2db9953a, 7003aba4, 6f50ff64, b1a41311,
222515bf, a0dcdeea, 0aa9e03f, 61437b27, 352e68da, 88e8fa67,
bc8b36fa, 6e515f1d, 017d088c, 035a4cb3, 588a1ff7, 6d63b57d,
a2f13c19, 794d1c86, ab98ec65, 1026006d
- Removed a lot of dead ifdef code.
- edit/emacs.c: Hide an assignment to avoid a -Wunused warning. (See
also https://github.com/att/ast/pull/753, which removed the assignment
because ksh2020 removed the !SHOPT_MULTIBYTE code.)
- sh/nvdisc.c: The sh_newof macro cannot return a null pointer because
it will instead cause the shell to exit if memory cannot be allocated.
That makes the if statement here a no-op, so remove it.
- sh/xec.c: Fixed one unused variable warning in sh_funscope().
- sh/xec.c: Remove a fallthrough comment added in commit ed478ab7
because the TFORK code doesn't fall through (GCC also produces no
-Wimplicit-fallthrough warning here).
- data/builtins.c: The cd and pwd man pages state that these builtins
default to -P if PATH_RESOLVE is 'physical', which isn't accurate:
$ /opt/ast/bin/getconf PATH_RESOLVE
physical
$ mkdir /tmp/dir; ln -s /tmp/dir /tmp/sym
$ cd /tmp/sym
$ pwd
/tmp/sym
$ cd -P /tmp/sym
$ pwd
/tmp/dir
The behavior described by these man pages isn't specified in the ksh
man page or by POSIX, so to avoid changing these builtin's behavior
the inaccurate PATH_RESOLVE information has been removed.
- Mamfiles: Preserve multi-line errors by quoting the $x variable.
This fix was backported from 93v-.
(See also <https://github.com/lkujaw/ast/commit/a7e9cc82>.)
- sh/subshell.c: Remove set but not used sp->errcontext variable.
