CVSROOT: /cvs
Module name: src
Changes by: k...@cvs.openbsd.org 2022/10/10 08:57:48
Modified files:
bin/ksh : exec.c
Added files:
regress/bin/ksh: trap.t
Log message:
Trigger ERR trap on permanent I/O redirection failure
The following three cases behave identical in bash(1), but our ksh
(ksh93 also) fails to run the trap in the last case:
(non-zero exit code is trigger, no redirection)
$ ksh -c 'trap "echo ERR" ERR ; false'
ERR
(failed redirection is trigger, 'echo' was not executed)
$ ksh -c 'trap "echo ERR" ERR ; echo >/'
ksh: cannot create /: Is a directory
ERR
(failed redirection, no execution, trap was NOT triggered)
$ ksh -c 'trap "echo ERR" ERR ; exec >/'
ksh: cannot create /: Is a directory
bash(1) prints "ERR" in all three cases, as expected.
ksh93 behaves like our ksh(1).
In ksh `exec' is a builtin (CSHELL), but also special (SPEC_BI):
$ type alias
alias is a shell builtin
$ type exec
exec is a special shell builtin
Without command and redirection alone, `exec' permanently redirects I/O for
the shell itself, not executing anything; it is the only (special) builtin
with such a special use-case, implemented as c_sh.c:c_exec().
This corner-case is overlooked in exec.c:execute() which handles iosetup()
failure for all commands, incl. builtins.
Exclude c_exec() from the rest of special builtins to ensure it runs the
ERR trap as expected:
$ ./obj/ksh -c 'trap "echo ERR" ERR ; exec >/'
ksh: cannot create /: Is a directory
ERR
Also add three new regress cases covering this; rest keep passing.
OK millert
