1.\" $NetBSD: link.2,v 1.9 1997/03/27 07:57:12 mikel Exp $ 2.\" 3.\" Copyright (c) 1980, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)link.2 8.3 (Berkeley) 1/12/94 35.\" 36.Dd January 12, 1994 37.Dt LINK 2 38.Os BSD 4 39.Sh NAME 40.Nm link 41.Nd make a hard file link 42.Sh SYNOPSIS 43.Fd #include <unistd.h> 44.Ft int 45.Fn link "const char *name1" "const char *name2" 46.Sh DESCRIPTION 47The 48.Fn link 49function call 50atomically 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 60to the 61underlying object. 62.Pp 63If 64.Fa name1 65is removed, the file 66.Fa name2 67is not deleted and the link count of the 68underlying object is 69decremented. 70.Pp 71.Fa Name1 72must exist for the hard link to 73succeed and 74both 75.Fa name1 76and 77.Fa name2 78must be in the same file system. 79.Fa Name1 80may not be a directory unless the caller is the super-user 81and the file system containing it supports linking to directories. 82.Sh RETURN VALUES 83Upon successful completion, a value of 0 is returned. Otherwise, 84a value of -1 is returned and 85.Va errno 86is set to indicate the error. 87.Sh ERRORS 88.Fn Link 89will fail and no link will be created if: 90.Bl -tag -width Er 91.It Bq Er ENOTDIR 92A component of either path prefix is not a directory. 93.It Bq Er ENAMETOOLONG 94A component of a pathname exceeded 95.Dv {NAME_MAX} 96characters, or an entire path name exceeded 97.Dv {PATH_MAX} 98characters. 99.It Bq Er ENOENT 100A component of either path prefix does not exist. 101.It Bq Er EACCES 102A component of either path prefix denies search permission. 103.It Bq Er EACCES 104The requested link requires writing in a directory with a mode 105that denies write permission. 106.It Bq Er ELOOP 107Too many symbolic links were encountered in translating one of the pathnames. 108.It Bq Er ENOENT 109The file named by 110.Fa name1 111does not exist. 112.It Bq Er EOPNOTSUPP 113The file system containing the file named by 114.Fa name1 115does not support links. 116.It Bq Er EMLINK 117The link count of the file named by 118.Fa name1 119would exceed 120.Dv {LINK_MAX}. 121.It Bq Er EEXIST 122The link named by 123.Fa name2 124does exist. 125.It Bq Er EPERM 126The file named by 127.Fa name1 128is a directory and the effective 129user ID is not super-user, 130or the file system containing the file does not permit the use of 131.Fn link 132on a directory. 133.It Bq Er EXDEV 134The link named by 135.Fa name2 136and the file named by 137.Fa name1 138are on different file systems. 139.It Bq Er ENOSPC 140The directory in which the entry for the new link is being placed 141cannot be extended because there is no space left on the file 142system containing the directory. 143.ne 3v 144.It Bq Er EDQUOT 145The directory in which the entry for the new link 146is being placed cannot be extended because the 147user's quota of disk blocks on the file system 148containing the directory has been exhausted. 149.It Bq Er EIO 150An I/O error occurred while reading from or writing to 151the file system to make the directory entry. 152.It Bq Er EROFS 153The requested link requires writing in a directory on a read-only file 154system. 155.It Bq Er EFAULT 156One of the pathnames specified 157is outside the process's allocated address space. 158.El 159.Sh SEE ALSO 160.Xr symlink 2 , 161.Xr unlink 2 162.Sh STANDARDS 163The 164.Fn link 165function conforms to 166.St -p1003.1-88 . 167