unlink() removes the directory entry named by the pathname pointed to by path and decrements the link count of the file referred to by that entry. If this entry was the last link to the file, and no process has the file open, then all resources associated with the file are reclaimed. If, however, the file was open in any process, the actual resource reclamation is delayed until it is closed, even though the directory entry has disappeared.

If path refers to a directory, the effective user-ID of the calling process must be super-user.

Upon successful completion, unlink() marks for update the st_ctime and st_mtime fields of the parent directory. Also, if the file's link count is not zero, the st_ctime field of the file is marked for update.

unlink() returns:

0

on success.

-1

on failure and sets errno to indicate the error.

EACCES

Search permission is denied for a component of the path prefix of path. Write permission is denied for the directory containing the link to be removed.

EBUSY

The entry to be unlinked is the mount point for a mounted file system.

EFAULT

path points outside the process's allocated address space.

EINVAL

The file referred to by path is the current directory,

EIO

An I/O error occurred while reading from or writing to the file system.

ELOOP

Too many symbolic links were encountered in translating path.

ENAMETOOLONG

The length of the path argument exceeds {PATH_MAX}. A pathname component is longer than {NAME_MAX} while {_POSIX_NO_TRUNC} is in effect (see pathconf(2V)).

ENOENT

The file referred to by path does not exist.

ENOTDIR

A component of the path prefix of path is not a directory.

EPERM

The file referred to by path is a directory and the effective user ID of the process is not the super-user.

EROFS

The file referred to by path resides on a read-only file system.

In addition to the above, the following may also occur:

ENOENT

path points to an empty string.

Applications should use rmdir(2V) to remove directories. Although root may use unlink() on directories, all users may use rmdir().