return directory portion of
dirname deletes the filename portion,
beginning with the last slash (‘/’) character to the end of
pathname, and writes the result to the standard
dirname utility exits 0 on
success, and >0 if an error occurs.
The following line sets the shell variable
FOO to /usr/bin:
basename(1), csh(1), sh(1), dirname(3)
dirname utility is compliant with the
IEEE Std 1003.1-2008 (“POSIX.1”)
dirname utility first appeared as an
expr(1) script in AT&T System III
UNIX. It was reimplemented in C for
4.3BSD-Reno and reimplemented again using
dirname(3) for OpenBSD 2.2.
The original BSD version was written by Keith Bostic. The current OpenBSD version was written by Todd Miller <email@example.com>.