'command -p' was broken for non-interactive shells as the variable
used to store the default system PATH, std_path, was not
initialised correctly. For instance:
$ ksh -c 'command -p ls'
ksh: ls: not found
This fix by Siteshwar Vashisht is backported from ksh2020.
Ref.:
https://github.com/att/ast/issues/426https://github.com/att/ast/pull/448
src/cmd/ksh93/sh/path.c:
- Correctly initialise std_path (the default PATH) when ksh is
started as a non-interactive shell.
src/cmd/ksh93/sh.1:
- Fix vague explanation of 'command -p'.
src/cmd/ksh93/tests/path.sh:
- Add regression test.
(cherry picked from commit a76439d60b70c18cf44d84c1962fcd8df84c947c)
Standard output (FD 1) tested as being on a terminal within a
command substitution, which makes no sense as the command
substitution is supposed to be catching standard output.
ksh -c 'v=$(echo begincomsub
[ -t 1 ] && echo oops
echo endcomsub)
echo "$v"'
This should not output "oops".
This is one of the many bugs with ksh93 virtual (non-forked)
subshells. On the abandoned Vashist/Rader ksh2020 branch, this bug
was fixed by changing quite a lot of code, which introduced and/or
exposed another bug:
https://github.com/att/ast/issues/1079https://github.com/att/ast/commit/8e1e405ehttps://github.com/att/ast/issues/1088
That issue was unresolved when the ksh2020 branch was abandoned.
The safer and more conservative fix is simply forcing the subshell
to fork if we're in a non-forked command substitution and testing
'-t 1'. It is hard to imagine a situation where this would cause a
noticable performance hit.
Note that this fix does not affect ksh93-specific "shared"
non-subshell ${ command substitutions; } which are executed in the
main shell environment, so that variables survive, etcetera.
'test -t 1' continues to wrongly return true there, but command
substitutions of that form cannot be forked because that would
defeat their purpose.
src/cmd/ksh93/bltins/test.c:
- Fix 'test -t 1', '[ -t 1 ]' and '[[ -t 1 ]]' by forking the
current subshell if it is a virtual/non-forked subshell
(shp->subshell), and a command substitution (shp->comsub), but
NOT a "shared" ${ command substitution; } (!shp->subshare).
src/cmd/ksh93/tests/bracket.sh:
- Add two regression tests for this issue, which were adapted from
the Vashist/Rader ksh2020 branch.
NEWS, src/cmd/ksh93/include/version.h:
- Update.
(cherry picked from commit b8ef05e457ead65b83417699b8dd8632f855e2fa)
This new wrapper script sets up the correct environment for running
the ksh93 regression test suite. It allows running the tests
without AST nmake, which is not maintained in this repository.
An alternative ksh to test may be passed in the $KSH env var.
bin/shtests:
- Added. Sets up environment before passing control to
'src/cmd/ksh93/tests/shtest'. Passes on any options given.
NEWS:
- Updated.
(cherry picked from commit 14ced94ed83991687c645a09bd2e45a5c2ffe8dc)
This allows scripts to check for a nonzero exit status on the
'print', 'printf' and 'echo' builtins and prevent possible infinite
loops if SIGPIPE is ignored.
sfsync() was already returning a negative value on I/O error, so
all we need to do is add a check. The stream buffer will need to be
filled before an I/O error can be detected, but this is the same on
other shells. See manual page: src/lib/libast/man/sfio.3
Ref.: https://github.com/att/ast/issues/1093https://github.com/att/ast/pull/1363
src/cmd/ksh93/bltins/print.c: b_print():
- Make sure an error result from sfsync() is reflected in the
output builtin's exit status (exitval).
- Write an I/O error message (e_io) if the exit status is nonzero.
src/cmd/ksh93/data/msg.c, src/cmd/ksh93/include/io.h:
- Add the e_io[] error message.
src/cmd/ksh93/tests/builtins.sh:
- Add I/O error regression test, checking for the correct error
message and exit status. All three output builtins use the same
b_print() function so we only need to test one.
src/cmd/ksh93/tests/basic.sh,
src/cmd/ksh93/tests/coprocess.sh:
- Redirect stderr on a few 'print' commands to /dev/null; these
now issue an expected I/O error. This does not cause failures.
NEWS, TODO:
- Update.
(cherry picked from commit 9011fa933552e483dab460f7dd1593d64e059d94)
This fix is backported from the Vashisht/Rader ksh2020 branch.
src/cmd/ksh93/bltins/print.c:
- Fix syncing history when print -s -f is used. For example, the
following now correctly adds a 'cd' command to the history:
print -s -f 'cd -- %q\n' "$PWD"
Ref.: https://github.com/att/ast/issues/425https://github.com/att/ast/pull/442
src/cmd/ksh93/include/version.h:
- Version date bump.
(cherry picked from commit 46ba7ecdc5c14cd73f6cb24b16c50bdc331a000e)
ksh used to redirect standard output by default when no file
descriptor was specified with the rarely used '<>' reading/writing
redirection operator. It now redirects standard input by default,
as POSIX specifies and as all other POSIX shells do. To redirect
standard output for reading and writing, you now need '1<>'.
Ref.: https://github.com/att/ast/issues/75http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_07_07
(cherry picked from commit 29afc16c47824fc79ed092ae7704c525b1db6a0a)
This fixes an undocumented 'case' pattern matching misbehaviour
(labelled BUG_CASELIT in modernish) that goes back to the original
Bourne shell, but wasn't discovered until 2018.
If a pattern doesn't match as a pattern, it's tried again as a
literal string. This breaks common validation use cases, such as:
n='[0-9]'
case $n in
( [0-9] ) echo "$n is a number" ;;
esac
would output "[0-9] is a number" as the literal string fallback
matches the pattern. As this misbehaviour was never documented
anywhere (not for Bourne, ksh88, or ksh93), and it was never
replicated in other shells (not even in ksh88 clones pdksh and
mksh), it is unlikely any scripts rely on it.
Of course, a literal string fallback, should it be needed, is
trivial to implement correctly without this breakage:
case $n in
( [0-9] | "[0-9]") echo "$n is a number or the number pattern" ;;
esac
src/cmd/ksh93/sh/xec.c:
- Remove trim_eq() function responsible for implementing the
misbehaviour described above.
NEWS:
- Added. Document this bugfix.
Ref.:
- The problem: thread starting at
https://www.mail-archive.com/austin-group-l@opengroup.org/msg02127.html
- The solution, thanks to George Koehler: comments/commits in
https://github.com/att/ast/issues/476
- Modernish BUG_CASELIT bug test & documentation:
https://github.com/modernish/modernish/commit/b2024ae3
(cherry picked from commit 8d6c8ce69884767a160c1e20049e77bdd849c248
with some extra edits to NEWS to upate the info for this reboot)
