ctags: ctags − Generate tag files for source code
ctags: 
ctags: Ctags generates an index (or tag) file of language objects found in
ctags: source files that allows these items to be quickly and easily located
ctags: by a text editor or other utility. A tag signifies a language object
ctags: for which an index entry is available (or, alternatively, the index
ctags: entry created for that object).
ctags: Tag generation is supported for the following languages: Assembler,
ctags: AWK, ASP, BETA, Bourne/Korn/Zsh Shell, C, C++, COBOL, Eiffel, Fortran,
ctags: Java, Lisp, Lua, Make, Pascal, Perl, PHP, Python, REXX, Ruby, S-Lang,
ctags: Scheme, Tcl, Vim, and YACC.