Where are functions in ANSI C such as strlen() or getchar() defined on a linux system? You are able to look through the header files but there's no definitions. Sometimes you see a declaration. I think someone told me a while back they are in shared object files *.so files in /usr/lib/. If this is correct, I was wondering how someone would make a shared object file like someone did in libpcap or libdnet? Thanks in advance.