while grep multiple files, how do I stop after first match?

Question

I have a list of patterns in a text file, for which I use bzgrep to match on multiple files:

for pattern in $(cat ~/patterns.txt); do echo $pattern; bzgrep -i $pattern *.bz2; done

How do I make bzgrep (grep) stop after the first match of the current pattern (I need it stop completely, not stop on the current file being grep'ed) and go on to the next pattern. I have read about "-m 1" parameter, but I think it only stops on the current file. Any ideas?

Thanks

Answer 1

Pipe the output of the grep to head -n 1; that will pull (& pass on) the first line and ignore the rest (i.e. kill the source pipe).

Answer 2

for pattern in $(< ~/patterns.txt); do
  echo "$pattern"
  for i in *.bz2; do
    bzgrep -i "$pattern" "$i" && break
  done
done

You may wish to add a -H to grep to display filename:line rather than just line.