Re: the bug with [[ $( type -p func ) ]] and the funky ! ----- Forwarded message from Chet Ramey ----- Date: Thu, 19 Nov 2009 21:56:22 -0500 From: Chet Ramey To: Isaac Good Subject: Re: [[ and set -E vs trap ERR Isaac Good wrote:
Configuration Information [Automatically generated, do not change]: Machine: i686 OS: linux-gnu Compiler: gcc Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' - DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H -I. -I. -I./include -I./lib -march=i686 -mtune=generic -O2 -pipe uname output: Linux arch 2.6.31-ARCH #1 SMP PREEMPT Fri Oct 23 11:12:58 CEST 2009 i686 Pentium III (Katmai) GenuineIntel GNU/Linux Machine Type: i686-pc-linux-gnu
Bash Version: 4.0 Patch Level: 35 Release Status: release
cat <<-EOF >test #!/bin/bash -e set -E trap 'echo >&2 "error"' ERR
echo TEST1 if [ $(false) ] ; then echo 1 fi
echo TEST2 if [[ $(false) ]] ; then echo 1 fi EOF
Expected output: TEST1 TEST2
Actual output: TEST1 TEST2 error
The [[ masks the fact that an 'if' is running - but only in regards to the trap. bash does not exit on this error but the trap is triggered. [ works fine. With set -E, the trap is inherited by command substitution, but the fact that the trap is suppressed is not.
<\amethyst> but the manpage says the ERR trap is avoided under "the same conditions obeyed by the errexit option", so at least the documentation is in error if nothing else
In bash-4.0, the conditional command does not honor the set -e option, and as a result, doesn't pay attention to set -E either. The [[ and (( commands will honor set -e in bash-4.1. Chet -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, ITS, CWRU chet@case.edu http://cnswww.cns.cwru.edu/~chet/ ----- End forwarded message -----