rmdir - delete a directory
#include <unistd.h>
int rmdir(const char *pathname);
rmdir(2) deletes a directory, which must be empty.
On success, zero is returned. On error, -1 is returned, and errno is set appropriately.
SVr4, SVID, POSIX, BSD 4.3
Infelicities in the protocol underlying NFS can cause the unexpected disappearance of directories which are still being used.