[leaf-devel] inverting exit status
Shell gurus, Is there a reliable cross-platform way to write an inverted if statement? Something like bash's: if ! /usr/bin/false # with some other command, obviously then # do something true else # do something false fi Your assistance is greatly appreciated. Chad --- This SF.Net email sponsored by Black Hat Briefings Training. Attend Black Hat Briefings Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com ___ leaf-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/leaf-devel
Re: [leaf-devel] inverting exit status
On Mon, 2004-07-05 at 17:39, Chad Carr wrote: Shell gurus, Chad, I'm by no means a shell guru, but this Google string may help. Google string: inverted if posix ash Is there a reliable cross-platform way to write an inverted if statement? Something like bash's: if ! /usr/bin/false # with some other command, obviously then # do something true else # do something false fi Your assistance is greatly appreciated. I hope this is helpful. -- Mike Noyes mhnoyes at users.sourceforge.net http://sourceforge.net/users/mhnoyes/ SF.net Projects: ffl, leaf, phpwebsite, phpwebsite-comm, sitedocs --- This SF.Net email sponsored by Black Hat Briefings Training. Attend Black Hat Briefings Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com ___ leaf-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/leaf-devel
Re: [leaf-devel] inverting exit status
Chad Carr wrote:
Shell gurus,
Is there a reliable cross-platform way to write an inverted if
statement? Something like bash's:
if ! /usr/bin/false # with some other command, obviously
then
# do something true
else
# do something false
fi
Your assistance is greatly appreciated.
Just shuffle the then and else code around as appropriate for the
sense of the exit condition you're checking for.
If that's not an option (ie: you're only checking one case, and don't
want an empty then), you can do something like
if /usr/bin/false ; [ $? -ne 0 ] ; then
...
or more typically:
/usr/bin/false
if [ $? -ne 0 ] ; then
...
or even:
/usr/bin/false
retcode=$?
...
if [ $retcode -ne 0 ] ; then
...
If you're just trying to test for error codes or something, the
following might be handy:
abort() { ... }
# Call an abort procedure if command1 fails
/usr/bin/command1 || abort
# Run several commands if command2 fails
/usr/bin/command2 || { echo ERROR!!! ; exit ; }
HTH
--
Charles Steinkuehler
[EMAIL PROTECTED]
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