1.\" Copyright (c) 1980, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)unlink.2 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD: src/lib/libc/sys/unlink.2,v 1.8.2.4 2001/12/14 18:34:02 ru Exp $ 30.\" $DragonFly: src/lib/libc/sys/unlink.2,v 1.4 2007/04/26 17:35:03 swildner Exp $ 31.\" 32.Dd August 18, 2009 33.Dt UNLINK 2 34.Os 35.Sh NAME 36.Nm unlink 37.Nd remove directory entry 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In unistd.h 42.Ft int 43.Fn unlink "const char *path" 44.Sh DESCRIPTION 45The 46.Fn unlink 47function 48removes the link named by 49.Fa path 50from its directory and decrements the link count of the 51file which was referenced by the link. 52If that decrement reduces the link count of the file 53to zero, 54and no process has the file open, then 55all resources associated with the file are reclaimed. 56If one or more process have the file open when the last link is removed, 57the link is removed, but the removal of the file is delayed until 58all references to it have been closed. 59.Fa path 60may not be a directory. 61.Sh RETURN VALUES 62.Rv -std unlink 63.Sh ERRORS 64The 65.Fn unlink 66succeeds unless: 67.Bl -tag -width Er 68.It Bq Er ENOTDIR 69A component of the path prefix is not a directory. 70.It Bq Er ENAMETOOLONG 71A component of a pathname exceeded 255 characters, 72or an entire path name exceeded 1023 characters. 73.It Bq Er ENOENT 74The named file does not exist. 75.It Bq Er EACCES 76Search permission is denied for a component of the path prefix. 77.It Bq Er EACCES 78Write permission is denied on the directory containing the link 79to be removed. 80.It Bq Er ELOOP 81Too many symbolic links were encountered in translating the pathname. 82.It Bq Er EPERM 83The named file has its immutable or append-only flag set (see 84.Xr chflags 2 ) . 85.It Bq Er EPERM 86The named file is a directory. 87.It Bq Er EPERM 88The directory containing the file is marked sticky, 89and neither the containing directory nor the file to be removed 90are owned by the effective user ID. 91.It Bq Er EBUSY 92The entry to be unlinked is the mount point for a 93mounted file system. 94.It Bq Er EIO 95An I/O error occurred while deleting the directory entry 96or deallocating the inode. 97.It Bq Er EROFS 98The named file resides on a read-only file system. 99.It Bq Er EFAULT 100.Fa Path 101points outside the process's allocated address space. 102.El 103.Sh SEE ALSO 104.Xr close 2 , 105.Xr link 2 , 106.Xr rmdir 2 , 107.Xr unlinkat 2 , 108.Xr symlink 7 109.Sh HISTORY 110An 111.Fn unlink 112function call appeared in 113.At v6 . 114.Pp 115The 116.Fn unlink 117system call traditionally allows the super-user to unlink directories which 118can damage the filesystem integrity. This implementation no longer permits 119it. 120