Use command grep and locate

Question

How I can make the grep command locate certain words in the files specified by the routes found by the locate command?

locate my.cnf | grep user   

(I want that grep command search the word "user" on the files found for locate command)

Answer 1

If your search results are sure to return paths with no spaces, you could use xargs like this:

locate my.cnf | xargs grep user

However you should get in the habit of protecting yourself to handle the case where a path or filename might contain a space by telling xargs to use null as a separator and telling locate (or whatever program you are using to return strings) to also send that as the separator like this:

locate -0 my.cnf | xargs -0 grep user

This would work even if your path included blanks like /name with space/my.cnf.

Answer 2

One-liner:

for file in $(locate my.cnf) ; do grep -r user "$file" ; done

If you want to search pattern in files under the directory name you got from locate then -r will take care of it otherwise remove -r.

Answer 3

If I understand correctly, you could do something like this:

#!/bin/sh
typeset what1=$1
typeset what2=$2
[ "$#" -eq 2 ] || { echo "Two arguments expected"; exit 1; }
locate ${what1} | while read file; do
    grep ${what2} ${file} /dev/null
    done

This searches the files matching the locate argument (what1) for a string that matches what2. The dev/null argument forces grep to report the file name of a match.