header files in C

Should you have to include a header file into its own library? I can't understand why I sometimes, but not always, get compile errors because it's not getting the header file prototypes before it compiles the libraries.

>>48
you don't need to write the terminating null character.
and why are you writing to stderr that you can't write to stderr if you can't write to stdout, but don't yet know whether or not you can write to stderr?
also, not being able to write to stdout and/or stderr is not usually a fatal error.

tl;dr: you fucking moron