cscope
Efficient, text-only browser for C sources
Cscope is a text screen based source browser, which can double as a behind-the scenes source code navigation aid for classic programmers' editors like Emacs or Vim, too.
Based on a pre-parsed, condensed extract, and optionally a quick-lookup index, it finds and shows identified items in the entire source code, even of truly large projects, quickly and without fuss.