[hunter2_]

From the root of the repo:

  grep -HIron 'your search pattern' *

Sometimes I'll add -i (case-insensitive), or drop the -o (for some context but beware minified files), etc.

[xorcist]

It is convenient to add an alias for this. Mine includes

  --exclude-dir=.git --exclude-dir=.svn

(This is GNU grep specific.)

If there is no unicode setting "LC_ALL=C" can speed things up considerably too.