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Name

unlink - remove directory entry

Synopsis

#include <unistd.h>

int unlink(const char *path);

MT-Level

Async-Signal-Safe

Description

unlink() removes the directory entry named by the path name pointed to by path. and decrements the link count of the file referenced by the directory entry. When all links to a file have been removed and no process has the file open, the space occupied by the file is freed and the file ceases to exist. If one or more processes have the file open when the last link is removed, space occupied by the file is not released until all references to the file have been closed. If path is a symbolic link, the symbolic link is removed. path should not name a directory unless the process has appropriate privileges. Applications should use rmdir to remove directories.

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.

Return Values

Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.

Errors

The named file is unlinked unless one or more of the following are true:

EACCES
Search permission is denied for a component of the path prefix.
EACCES
Write permission is denied on the directory containing the link to be removed.
EACCES
The parent directory has the sticky bit set and the file is not writable by the user; the user does not own the parent directory and the user does not own the file.
EBUSY
The entry to be unlinked is the mount point for a mounted file system.
EFAULT
path points to an illegal address.
EINTR
A signal was caught during the unlink() function.
ELOOP
Too many symbolic links were encountered in translating path.
EMULTIHOP
Components of path require hopping to multiple remote machines and the file system does not allow it.
ENAMETOOLONG
The length of the path argument exceeds {PATH_MAX}, or the length of a path component exceeds {NAME_MAX} while {_POSIX_NO_TRUNC} is in effect.
ENOENT
The named file does not exist or is a null pathname.
ENOLINK
path points to a remote machine and the link to that machine is no longer active.
ENOTDIR
A component of the path prefix is not a directory.
EPERM
The named file is a directory and the effective user of the calling process is not super-user.
EROFS
The directory entry to be unlinked is part of a read-only file system.

See Also

rm(1) , close(2) , link(2) , open(2) , rmdir(2)

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