grep and path name matching.

stf92 · 07-16-2010, 06:05 PM

Linux kernel 2.6, Slackware 12.0.
Hi:

Question: I do grep -r string_1 .*txt. Is the path first expanded by the shell? If not, then say, ./elem1/elem2/file1.txt would search for string_1. However, it will not in my system. Note: '.' (period) in .*txt is any char. '.' in ./elem1/elem2/file1.txt is current dir. Now, .*txt should be, as a regexp, zero or more occurrences of any char followed by txt, that is, any string with txt as a suffix. Thanks.

ShadowCat8 · 07-16-2010, 07:05 PM

Well,

If I were to try to find all files referencing string_1 in files that were ending in ".txt", I think I would try something like this:

Code:

~ $ grep -r string_1 --include=*.txt ./*

or, to make more sense of it and cut down possible false results:

Code:

find . -name "*.txt" -print | grep string_1

HTH. Let us know.

stf92 · 07-16-2010, 08:26 PM

Thanks. The first command seems to work fine, although it would be difficult to test for "false results". As for the second one, I think you have missed something, for grep would then be looking into the path names and not into the contents of the files themselves. Regards.

ShadowCat8 · 07-26-2010, 02:03 PM

Greetings,

@stf92: You are correct. My fingers got ahead of my brain while I was typing and missed the (ahem...) cat. Hehe

So, really, the right way to do it for the second one would be something like:

Code:

for x in `find . -name "*.txt" -print`
     do
     cat ${x} | grep string_1
     if [ "$?" -eq "0" ]
          echo -e "File ${x} contains string_1.\n"
          fi
     done

HTH.