xref: /netbsd/bin/ln/ln.1 (revision c4a72b64)
1.\"	$NetBSD: ln.1,v 1.16 2002/09/25 15:18:39 wiz Exp $
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37.\"	@(#)ln.1	8.2 (Berkeley) 12/30/93
38.\"
39.Dd October 14, 2000
40.Dt LN 1
41.Os
42.Sh NAME
43.Nm ln
44.Nd make links
45.Sh SYNOPSIS
46.Nm
47.Op Fl fhns
48.Ar source_file
49.Op Ar target_file
50.Nm ""
51.Op Fl fhns
52.Ar source_file ... target_dir
53.Sh DESCRIPTION
54The
55.Nm
56utility creates a new directory entry (linked file) which has the
57same modes as the original file.
58It is useful for maintaining multiple copies of a file in many places
59at once without using up storage for the
60.Dq copies ;
61instead, a link
62.Dq points
63to the original copy.
64There are two types of links; hard links and symbolic links.
65How a link
66.Dq points
67to a file is one of the differences between a hard or symbolic link.
68.Pp
69The options are as follows:
70.Bl -tag -width flag
71.It Fl f
72Unlink any already existing file, permitting the link to occur.
73.It Fl h
74If the
75.Ar target_file
76or
77.Ar target_dir
78is a symbolic link, do not follow it.
79This is most useful with the
80.Fl f
81option, to replace a symlink which may point to a directory.
82.It Fl n
83Same as
84.Fl h ,
85for compatibility with other
86.Nm
87implementations.
88.It Fl s
89Create a symbolic link.
90.El
91.Pp
92By default
93.Nm
94makes
95.Em hard
96links.
97A hard link to a file is indistinguishable from the original directory entry;
98any changes to a file are effective independent of the name used to reference
99the file.
100Hard links may not normally refer to directories and may not span file systems.
101.Pp
102A symbolic link contains the name of the file to
103which it is linked.
104The referenced file is used when an
105.Xr open  2
106operation is performed on the link.
107A
108.Xr stat  2
109on a symbolic link will return the linked-to file; an
110.Xr lstat  2
111must be done to obtain information about the link.
112The
113.Xr readlink  2
114call may be used to read the contents of a symbolic link.
115Symbolic links may span file systems and may refer to directories.
116.Pp
117Given one or two arguments,
118.Nm
119creates a link to an existing file
120.Ar source_file  .
121If
122.Ar target_file
123is given, the link has that name;
124.Ar target_file
125may also be a directory in which to place the link;
126otherwise it is placed in the current directory.
127If only the directory is specified, the link will be made
128to the last component of
129.Ar source_file  .
130.Pp
131Given more than two arguments,
132.Nm
133makes links in
134.Ar target_dir
135to all the named source files.
136The links made will have the same name as the files being linked to.
137.Sh SEE ALSO
138.Xr link 2 ,
139.Xr lstat 2 ,
140.Xr readlink 2 ,
141.Xr stat 2 ,
142.Xr symlink 2 ,
143.Xr symlink 7
144.Sh STANDARDS
145The
146.Nm
147utility conforms to
148.St -p1003.2-92 .
149.Sh HISTORY
150A
151.Nm
152utility appeared in
153.At v6 .
154