int remove(const char *path);
The remove function causes the file whose name is the string pointed to by filename to be no longer accessible by that name. A subsequent attempt to open that file using that name fails, unless it is created anew. If the file is open, the behavior of the remove function is implementation-defined.
IEEE POSIX Std 1003.1-1990 System Application Program Interface (API) [C Language] (ISO/IEC 9945-1)
and NIST FIPS 151-1 .