Report the parent directory name of a file path name.
Standard C Library (libc.a)
char *dirname (path)
Given a pointer to a character string that contains a file system path name, the dirname subroutine returns a pointer to a string that is the parent directory of that file. Trailing "/" characters in the path are not counted as part of the path.
If path is a null pointer or points to an empty string, a pointer to a static constant "." is returned.
The dirname and basename subroutines together yield a complete path name. dirname (path) is the directory where basename (path) is found.
|path||Character string containing a file system path name.|
The dirname subroutine returns a pointer to a string that is the parent directory of path. If path or *path is a null pointer or points to an empty string, a pointer to a string "." is returned. The dirname subroutine may modify the string pointed to by path and may return a pointer to static storage that may then be overwritten by sequent calls to the dirname subroutine.
A simple file name and the strings "." and ".." all have "." as their return value.
|Input string||Output string|
The following code reads a path name, changes directory to the appropriate directory, and opens the file.
char path [MAXPATHEN], *pathcopy; int fd; fgets (path, MAXPATHEN, stdin); pathcopy = strdup (path); chdir (dirname (pathcopy) ); fd = open (basename (path), O_RDONLY);
This subroutine is part of Base Operating System (BOS) Runtime.
The basename or chdir subroutine.