report the parent directory name of a file path name
cc [flag . . . ] file . . . -lgen [library] . . .
char dirname(char path);
Given a pointer to a null-terminated character string that contains
a file system path name, dirname returns a pointer to a static
constant string that is the parent directory of that file.
In doing this, it sometimes places a null byte in the path name after
the next to last element, so the content of
must be disposable.
Trailing ``/'' characters in the path are not counted as part of the path.
does not contain ``/'', a pointer to a static constant . is returned.
together yield a complete path name.
dirname (path) is the directory where basename (path)