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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)link.2 8.3 (Berkeley) 1/12/94 33.\" $FreeBSD$ 34.\" 35.Dd March 5, 1999 36.Dt LINK 2 37.Os 38.Sh NAME 39.Nm link 40.Nd make a hard file link 41.Sh LIBRARY 42.Lb libc 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 call 51atomically creates the specified directory entry (hard link) 52.Fa name2 53with the attributes of the underlying object pointed at by 54.Fa name1 . 55If the link is successful: the link count of the underlying object 56is incremented; 57.Fa name1 58and 59.Fa name2 60share equal access and rights 61to the 62underlying object. 63.Pp 64If 65.Fa name1 66is removed, the file 67.Fa name2 68is not deleted and the link count of the 69underlying object is 70decremented. 71.Pp 72.Fa Name1 73must exist for the hard link to 74succeed and 75both 76.Fa name1 77and 78.Fa name2 79must be in the same file system. 80.Fa name1 81may not be a directory. 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 either pathname exceeded 255 characters, 95or entire length of either path name exceeded 1023 characters. 96.It Bq Er ENOENT 97A component of either path prefix does not exist. 98.It Bq Er EOPNOTSUPP 99The file system containing the file named by 100.Fa name1 101does not support links. 102.It Bq Er EMLINK 103The link count of the file named by 104.Fa name1 105would exceed 32767. 106.It Bq Er EACCES 107A component of either path prefix denies search permission. 108.It Bq Er EACCES 109The requested link requires writing in a directory with a mode 110that denies write permission. 111.It Bq Er ELOOP 112Too many symbolic links were encountered in translating one of the pathnames. 113.It Bq Er ENOENT 114The file named by 115.Fa name1 116does not exist. 117.It Bq Er EEXIST 118The link named by 119.Fa name2 120does exist. 121.It Bq Er EPERM 122The file named by 123.Fa name1 124is a directory. 125.It Bq Er EXDEV 126The link named by 127.Fa name2 128and the file named by 129.Fa name1 130are on different file systems. 131.It Bq Er ENOSPC 132The directory in which the entry for the new link is being placed 133cannot be extended because there is no space left on the file 134system containing the directory. 135.It Bq Er EDQUOT 136The directory in which the entry for the new link 137is being placed cannot be extended because the 138user's quota of disk blocks on the file system 139containing the directory has been exhausted. 140.It Bq Er EIO 141An I/O error occurred while reading from or writing to 142the file system to make the directory entry. 143.It Bq Er EROFS 144The requested link requires writing in a directory on a read-only file 145system. 146.It Bq Er EFAULT 147One of the pathnames specified 148is outside the process's allocated address space. 149.El 150.Sh SEE ALSO 151.Xr readlink 2 , 152.Xr symlink 2 , 153.Xr unlink 2 154.Sh STANDARDS 155The 156.Fn link 157function call is expected to conform to 158.St -p1003.1-90 . 159.Sh HISTORY 160A 161.Fn link 162function call appeared in 163.At v7 . 164.Pp 165The 166.Fn link 167system call traditionally allows the super-user to link directories which 168corrupts the filesystem coherency. This implementation no longer permits 169it. 170