UNLINK(S) UNIX System V UNLINK(S)
Name
unlink - remove directory entry
Syntax
int unlink (path)
char *path;
Description
unlink removes the directory entry named by the path name
pointed to by path.
The named file is unlinked unless one or more of the
following is true:
[ENOTDIR] A component of the path prefix is not a
directory.
[ENOENT] The named file does not exist.
[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.
[EPERM] The named file is a directory and the
effective user ID of the process is not
super-user.
[EBUSY] The entry to be unlinked is the mount point
for a mounted file system.
[ETXTBSY] The entry to be unlinked is the last link to
a pure procedure (shared text) file that is
being executed.
[EROFS] The directory entry to be unlinked is part of
a read-only file system.
[EFAULT] path points outside the process's allocated
address space.
[EINTR] A signal was caught during the unlink system
call.
[ENOLINK] path points to a remote machine and the link
to that machine is no longer active.
[EMULTIHOP] Components of path require hopping to
multiple remote machines.
A file will not be unlinked when all of the following
conditions are true:
the parent directory has the sticky bit set
the file is not writable by the user
the user does not own the parent directory
the user does not own the file
the user is not root
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, the removal is
postponed until all references to the file have been closed.
See Also
close(S), link(S), open(S), rm(C)
Diagnostics
Upon successful completion, a value of 0 is returned.
Otherwise, a value of -1 is returned and errno is set to
indicate the error.
Standards Conformance
unlink is conformant with:
AT&T SVID Issue 2, Select Code 307-127;
The X/Open Portability Guide II of January 1987;
IEEE POSIX Std 1003.1-1988 with C Standard Language-
Dependent System Support;
and NIST FIPS 151-1.
(printed 6/20/89)