Re: postinst script

[Morgan Gangwere <0.fractalus@gmail.com>]

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On Tue, 7 Sep 2010 23:04:56 +0300
Zvi Dubitzky <DUBI@il.ibm.com> wrote:

> Hi
> 
> I have a command line in postinst script of a package that works ok 
> outside a package install context .
> one line is causing an error :
> 
> cat  /proc/file  | grep XY   > file 

grep returns 1 if it doesn't something that matches your expression.

add an echo if you don't care about your result or you want to change
something along the way....


cat /proc/file | grep XY > file
if [ $? -eq 0 ]; then
	# Success condition...
	echo "Found XY!"
	cat file
else
	# Exit condition...
	echo "Didn't find XY!"
	echo "Check XX and YY that there is in fact what you need."
fi

By default (if my bash-fu is correct), $? (if we're talking bash) will
result in the last return call.. So if i have a script which calls

grep test /proc/file

last and doesn't actually call exit or return, $? will contain the
return value of grep as though you had said

return $?

So, either check what you're doing with grep (which may be your biggest
problem!) or eat the value of $? by calling an echo "" (or just return!)

- -- 
Morgan Gangwere
Key ID A8B6F243, available from MIT.
BOFH excuse #301:

appears to be a Slow/Narrow SCSI-0 Interface problem
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