GNU grep is 10x faster than Mac grep

Before:

mozilla-central$ which grep /usr/bin/grep mozilla-central$ time git ls-files -z | xargs -0 grep foobar > /dev/null real 0m19.583s user 0m18.853s sys  0m0.722s

After:

mozilla-central$ which grep /opt/local/bin/grep mozilla-central$ time git ls-files -z | xargs -0 grep foobar > /dev/null real 0m1.386s user 0m0.754s sys  0m0.613s

via jlebar.com

http://scalper.posterous.com/gnu-grep-is-10x-faster-than-mac-grep