Identify Functions Definition within a C Source File

1. Use the ctags tools, on a console, typing in "ctags -x --c-kinds=f " with the file name(s) (e.g. "flex.c"):

ctags -x --c-kinds=f flex.c

will generate the list of C functions defined in "flex.c" file:

FlexParser       function   2228 flex.c           extern parserDefinition* FlexParser (void)
addContext       function    786 flex.c           static void addContext (tokenInfo* const parent, const tokenInfo* const child)
addToScope       function    796 flex.c           static void addToScope (tokenInfo* const token, vString* const extra)
buildFlexKeywordHash function    207 flex.c           static void buildFlexKeywordHash (void)
copyToken        function    705 flex.c           static void copyToken (tokenInfo *const dest, tokenInfo *const src)
...

Ref.: http://ctags.sourceforge.net/ctags.html