james@bigtex.cactus.org (James Van Artsdalen) (06/14/89)
On feature I miss from ksh is 'trap "" ERR'. For example, my .ksh file has trap 'echo "(ERR:$?)"' ERR I tried to simulate this in bash with PROMPT_COMMAND, but it didn't work. Here's an emacs M-x shell script: it starts out in ksh, and then runs bash. /tmp> (exit 1) (ERR:1) /tmp> /usr/local/src/dist-bash/bash /tmp> PROMPT_COMMAND='if [ $? -ne 0 ] ; then echo "(ERR:$?)" ; fi' PPROMPT_COMMAND='if [ $? -ne 0 ] ; then echo "(ERR:$?)" ; fi' /tmp> /tmp> (exit 1) ((exit 1) /tmp> bash doesn't print the error status. Also note that bash doesn't behave well under emacs, but I assume this is related to previous reported bugs with determining interactive status. -- James R. Van Artsdalen james@bigtex.cactus.org "Live Free or Die" Dell Computer Co 9505 Arboretum Blvd Austin TX 78759 512-338-8789
composer@BU-CS.BU.EDU (06/14/89)
| Date: 13 Jun 89 17:51:14 GMT | From: milano!bigtex!james@cs.utexas.edu (James Van Artsdalen) | | On feature I miss from ksh is 'trap "" ERR'. For example, my .ksh | file has | | trap 'echo "(ERR:$?)"' ERR | | I tried to simulate this in bash with PROMPT_COMMAND, but it didn't | work. Here's an emacs M-x shell script: it starts out in ksh, and | then runs bash. | | /tmp> (exit 1) | (ERR:1) | /tmp> /usr/local/src/dist-bash/bash | /tmp> PROMPT_COMMAND='if [ $? -ne 0 ] ; then echo "(ERR:$?)" ; fi' | PROMPT_COMMAND='if [ $? -ne 0 ] ; then echo "(ERR:$?)" ; fi' | /tmp> | | /tmp> (exit 1) | (exit 1) | /tmp> | | bash doesn't print the error status. Also note that bash doesn't | behave well under emacs, but I assume this is related to previous | reported bugs with determining interactive status. You had the right idea. The problem (I believe) with your emulation is that the status ($?) gets reset after the test. You could set up a function to do the same thing as follows: function ERR () { local err=$? if [ $? -ne 0 ]; then echo "(ERR:err)" fi } and then set PROMPT_COMMAND=ERR That should work. Actually, there seems to be a problem with the return status from a subshell not getting returned properly. Or, is it supposed to? Haven't looked into it yet. But, "(exit 1)" was returning 0. There also may be better methods of doing this, but I was just taking what you had already presented. Enjoy... | James R. Van Artsdalen james@bigtex.cactus.org "Live Free or Die" | Dell Computer Co 9505 Arboretum Blvd Austin TX 78759 512-338-8789 -jeff Jeff Kellem INTERNET: composer@bu-cs.bu.edu (or composer%bu-cs.bu.edu@bu-it.bu.edu) UUCP: ...!harvard!bu-cs!composer
ray@GIBBS.PHYSICS.PURDUE.EDU (Ray Moody) (06/14/89)
| bash doesn't print the error status. Also note that bash doesn't | behave well under emacs, but I assume this is related to previous | reported bugs with determining interactive status. >You had the right idea. The problem (I believe) with your emulation is >that the status ($?) gets reset after the test. You could set up a >function to do the same thing as follows: Remember that there is a known bug with $?. Try applying the fix I posted earlier. Ray