1.\" $OpenBSD: link.2,v 1.13 2000/10/18 05:12:10 aaron Exp $ 2.\" $NetBSD: link.2,v 1.7 1995/02/27 12:34:01 cgd Exp $ 3.\" 4.\" Copyright (c) 1980, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)link.2 8.3 (Berkeley) 1/12/94 36.\" 37.Dd January 12, 1994 38.Dt LINK 2 39.Os 40.Sh NAME 41.Nm link 42.Nd make a hard file link 43.Sh SYNOPSIS 44.Fd #include <unistd.h> 45.Ft int 46.Fn link "const char *name1" "const char *name2" 47.Sh DESCRIPTION 48The 49.Fn link 50function atomically creates the specified directory entry (hard link) 51.Fa name2 52with the attributes of the underlying object pointed at by 53.Fa name1 . 54If the link is successful: the link count of the underlying object 55is incremented; 56.Fa name1 57and 58.Fa name2 59share equal access and rights to the underlying object. 60.Pp 61If 62.Fa name1 63is removed, the file 64.Fa name2 65is not deleted and the link count of the underlying object is decremented. 66.Pp 67.Fa name1 68must exist for the hard link to succeed and both 69.Fa name1 70and 71.Fa name2 72must be in the same file system. 73As mandated by POSIX.1 74.Fa name1 75may not be a directory. 76.Sh RETURN VALUES 77Upon successful completion, a value of 0 is returned. 78Otherwise, a value of \-1 is returned and 79.Va errno 80is set to indicate the error. 81.Sh ERRORS 82.Fn link 83will fail and no link will be created if: 84.Bl -tag -width Er 85.It Bq Er ENOTDIR 86A component of either path prefix is not a directory. 87.It Bq Er ENAMETOOLONG 88A component of a pathname exceeded 89.Dv {NAME_MAX} 90characters, or an entire path name exceeded 91.Dv {PATH_MAX} 92characters. 93.It Bq Er ENOENT 94A component of either path prefix does not exist. 95.It Bq Er EOPNOTSUPP 96The file system containing the file named by 97.Fa name1 98does not support links. 99.It Bq Er EMLINK 100The link count of the file named by 101.Fa name1 102would exceed 103.Dv LINK_MAX . 104.It Bq Er EACCES 105A component of either path prefix denies search permission. 106.It Bq Er EACCES 107The requested link requires writing in a directory with a mode 108that denies write permission. 109.It Bq Er ELOOP 110Too many symbolic links were encountered in translating one of the pathnames. 111.It Bq Er ENOENT 112The file named by 113.Fa name1 114does not exist. 115.It Bq Er EEXIST 116The link named by 117.Fa name2 118does exist. 119.It Bq Er EPERM 120The file named by 121.Fa name1 122is a directory and the effective 123user ID is not superuser, 124or the file system containing the file does not permit the use of 125.Fn link 126on a directory. 127.It Bq Er EXDEV 128The link named by 129.Fa name2 130and the file named by 131.Fa name1 132are on different file systems. 133.It Bq Er ENOSPC 134The directory in which the entry for the new link is being placed 135cannot be extended because there is no space left on the file 136system containing the directory. 137.It Bq Er EDQUOT 138The directory in which the entry for the new link 139is being placed cannot be extended because the 140user's quota of disk blocks on the file system 141containing the directory has been exhausted. 142.It Bq Er EIO 143An I/O error occurred while reading from or writing to 144the file system to make the directory entry. 145.It Bq Er EROFS 146The requested link requires writing in a directory on a read-only file 147system. 148.It Bq Er EFAULT 149One of the pathnames specified 150is outside the process's allocated address space. 151.El 152.Sh SEE ALSO 153.Xr readlink 2 , 154.Xr symlink 2 , 155.Xr unlink 2 156.Sh STANDARDS 157The 158.Fn link 159function is expected to conform to 160.St -p1003.1-88 . 161