Re: Bug#454690: "grep -v" alway returns 0

[Eduard Bloch]

#include <hallo.h>
* Wacek Kusnierczyk [Sun, Mar 29 2009, 06:51:43PM]:

> maybe i can help a little.

Yeah, nice lesson Mr. Teacher, but I did not ask for help. It's
obviosuly working correctly (if you follow the book manpage) but the
result is not very practical.

Simple use case:

if do | some | thing | grep -v patternOfSuspiciousStuff > clean_file ; then
   ...

I want to receive filtered output _and_ receive a return code which
tells me whether anything has been filtered in the pipe or not. With the
current implementation, the exit status is almost useless (because I can
check easily whether the output is empty, if needed). What I need to know
is whether the -v expression has been matched somewhere; AFAICS I can do
that only by dumpfing prefiltered data and comparing with grep output.

Anyway, I am closing the BTS entry, PEBCAK.

Regards,
Eduard.
-- 
<Fuchur> Der schwierigste Teil bei der Debian-Installation ist immer, sich
        einen Namen für den Rechner auszudenken. *grübel*