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Re: [vox-tech] bash, short circuit logic, and errexit
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Re: [vox-tech] bash, short circuit logic, and errexit



This page seems to clarify that behavior

http://www.ss64.com/bash/set.html

saying that statements in while loops or && chains don't cause the script to exit on failure. Seems sensible since those are designed to give different behavior depending on the exit status of commands. You can always check the $? variable and exit based on that (yeah, makes the script longer, which is probably what you're trying to avoid with "set -e" -- sorry).

-Harold

On Jan 18, 2008, at 11:08 AM, Bryan Richter wrote:

Does everyone agree that the following script shouldn't last forever?
And if you agree, does it last forever nonetheless?

----------
#!/bin/bash

set -e

false && false;

while true; do
   echo "Still here"
   sleep 1
done

---------

I discovered that 'diff -q $file1 $file2 && echo "no differences"'
wasn't ending my script, in spite of having 'set -e'. From the example
above, which does last forever, it looks like all short-circuit logic
confounds it.

bash 3.00.15(1)-release

Red Hat Enterprise Linux ES release 4 (Nahant Update 4)



--
Bryan Richter
aka chreekat
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