Grep and Find are my two favorite extremely powerful Bash commands. How I use them …
Bash seems supported now on Linux, Mac and Windows, so use anywhere.
QuickTip for Mac Users
You can use CMD+UP and CMD+DOWN to navigate command line output. Super handy. It will jump past all the output to the last command line invocation so you can read the output.
grep -rnI MySearchString /path/to/dir/