Command to run another command against a list of files

psweetma · 11-09-2005, 02:11 PM

Hi,

Can anyone prompt my memory on how to do this...

In the bash shell I have a recursive grep command which returns a list of matching files, e.g.

grep -rl mypattern .

I want to then grep over this list of files again to see which ones match another pattern. I believe I need to pipe the grep into a command which will run another arbitrary command (in this case my second grep) against the list of files that results from the first command (in this case my first grep), but I can't remember what it is....

Thanks,
P.

psweetma · 11-09-2005, 02:46 PM

ah ok, i've just remembered, i was thinking of the 'xargs' command:

grep -rl '\.accept(' . | xargs grep -n '\.select('

P.

Back_to_Linux · 11-09-2005, 03:26 PM

#list=`grep -rl petern`
#grep -rl $list
or
#PATERN=your_patern
#grep -rl $PATERN $(grep -rl $PATERN $YOUR_PATH)

psweetma · 11-09-2005, 05:29 PM

oh ok, i didn't realise you could also do it like that. i'm still learning about linux shells and bash.

thank you - this looks like a very powerful and fundamental mechanism.

P.