ripgrep

ripgrep searches a whole directory tree by regex and tells you how long it took. It skips what .gitignore lists and what is binary without being asked, which is most of the reason it is quick.

The demo opens git's own source — 4,523 files it will search and 84 more it will skip. Try rg the_repository --stats, then -t c to search only the C files, -C 2 for the lines around each hit, -l for file names only, and --no-ignore to look inside the one file .gitignore has been hiding. The VM is private to your browser tab; nothing you type leaves it.