UNIX filenames

Filenames are case sensitive, meaning that the names a.out, A.out, and A.OUT are unique under UNIX.

Certain file suffixes indicate specific file types. The more common ones include:

.f     a FORTRAN source file

.c	    a C source file

.o     an object file produced by 
            the compiler

.s     an Assembly language file (CAL) on UNICOS.