Copyright (c) 1980, 1991, 1993
The Regents of the University of California. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. Neither the name of the University nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
@(#)unlink.2 8.1 (Berkeley) 6/4/93
.Dd September 2, 2019 .Dt UNLINK 2 .Os .Sh NAME .Nm unlink , .Nm unlinkat .Nd remove directory entry .Sh LIBRARY .Lb libc .Sh SYNOPSIS n unistd.h .Ft int .Fn unlink "const char *path" n fcntl.h .Ft int .Fn unlinkat "int fd" "const char *path" "int flag" .Sh DESCRIPTION The .Fn unlink function removes the link named by .Fa path from its directory and decrements the link count of the file which was referenced by the link. If that decrement reduces the link count of the file to zero, and no process has the file open, then all resources associated with the file are reclaimed. If one or more process have the file open when the last link is removed, the link is removed, but the removal of the file is delayed until all references to it have been closed.
p
.Fn unlinkat
works the same way as
.Fn unlink
except if
.Fa path
is relative.
In that case, it is looked up from a directory whose file
descriptor was passed as
.Fa fd .
Search permission is required on this directory.
(These alternatives await a decision about the semantics of O_SEARCH)
Search permission is required on this directory
except if
.Fa fd
was opened with the
.Dv O_SEARCH
flag.
- or -
This file descriptor must have been opened with the
.Dv O_SEARCH
flag.
.Fa fd
can be set to
.Dv AT_FDCWD
in order to specify the current directory.
p .Fn unlinkat will remove directories just like .Xr rmdir 2 , provided .Dv AT_REMOVEDIR is set in .Fa flag . .Sh RETURN VALUES .Rv -std unlink unlinkat .Sh ERRORS The .Fn unlink and .Fn unlinkat functions succeed unless: l -tag -width Er t Bq Er EACCES Search permission is denied for a component of the path prefix, or write permission is denied on the directory containing the link to be removed. t Bq Er EBUSY The entry to be unlinked is the mount point for a mounted file system. t Bq Er EFAULT .Fa path points outside the process's allocated address space. t Bq Er EIO An I/O error occurred while deleting the directory entry or deallocating the inode. t Bq Er ELOOP Too many symbolic links were encountered in translating the pathname. t Bq Er ENAMETOOLONG A component of a pathname exceeded rq Dv NAME_MAX characters, or an entire path name exceeded rq Dv PATH_MAX characters. t Bq Er ENOENT The named file does not exist. t Bq Er ENOTDIR A component of the path prefix is not a directory. t Bq Er EPERM The named file is a directory and the effective user ID of the process is not the super-user, the file system containing the file does not permit the use of .Fn unlink on a directory, or the directory containing the file is marked sticky, and neither the containing directory nor the file to be removed are owned by the effective user ID. t Bq Er EROFS The named file resides on a read-only file system. .El
p In addition, .Fn unlinkat will fail if: l -tag -width Er t Bq Er EBADF .Fa path does not specify an absolute path and .Fa fd is neither .Dv AT_FDCWD nor a valid file descriptor open for reading or searching. t Bq Er ENOTDIR .Fa path is not an absolute path and .Fa fd is a file descriptor associated with a non-directory file; or .Fa flag has .Dv AT_REMOVEDIR set and .Fa path does not name a directory. t Bq Er ENOTEMPTY .Fa flag has .Dv AT_REMOVEDIR set and .Fa path is a directory that is not empty. .El .Sh SEE ALSO .Xr close 2 , .Xr link 2 , .Xr rmdir 2 , .Xr symlink 7 .Sh STANDARDS The .Fn unlink function conforms to .St -p1003.1-90 . .Fn unlinkat conforms to .St -p1003.1-2008 . .Sh HISTORY An .Fn unlink function call appeared in .At v1 .
Indexes created Mon Sep 22 13:09:51 GMT 2025