xref: /freebsd/bin/ln/ln.1 (revision aa0a1e58)
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32.\"	@(#)ln.1	8.2 (Berkeley) 12/30/93
33.\" $FreeBSD$
34.\"
35.Dd July 17, 2009
36.Dt LN 1
37.Os
38.Sh NAME
39.Nm ln ,
40.Nm link
41.Nd link files
42.Sh SYNOPSIS
43.Nm
44.Op Fl L | Fl P | Fl s Op Fl F
45.Op Fl f | iw
46.Op Fl hnv
47.Ar source_file
48.Op Ar target_file
49.Nm
50.Op Fl L | Fl P | Fl s Op Fl F
51.Op Fl f | iw
52.Op Fl hnv
53.Ar source_file ...
54.Ar target_dir
55.Nm link
56.Ar source_file Ar target_file
57.Sh DESCRIPTION
58The
59.Nm
60utility creates a new directory entry (linked file) for the file name
61specified by
62.Ar target_file .
63The
64.Ar target_file
65will be created with the same file modes as the
66.Ar source_file .
67It is useful for maintaining multiple copies of a file in many places
68at once without using up storage for the
69.Dq copies ;
70instead, a link
71.Dq points
72to the original copy.
73There are two types of links; hard links and symbolic links.
74How a link
75.Dq points
76to a file is one of the differences between a hard and symbolic link.
77.Pp
78The options are as follows:
79.Bl -tag -width flag
80.It Fl F
81If the target file already exists and is a directory, then remove it
82so that the link may occur.
83The
84.Fl F
85option should be used with either
86.Fl f
87or
88.Fl i
89options.
90If none is specified,
91.Fl f
92is implied.
93The
94.Fl F
95option is a no-op unless
96.Fl s
97option is specified.
98.It Fl L
99When creating a hard link to a symbolic link,
100create a hard link to the target of the symbolic link.
101This is the default.
102This option cancels the
103.Fl P
104option.
105.It Fl P
106When creating a hard link to a symbolic link,
107create a hard link to the symbolic link itself.
108This option cancels the
109.Fl L
110option.
111.It Fl f
112If the target file already exists,
113then unlink it so that the link may occur.
114(The
115.Fl f
116option overrides any previous
117.Fl i
118and
119.Fl w
120options.)
121.It Fl h
122If the
123.Ar target_file
124or
125.Ar target_dir
126is a symbolic link, do not follow it.
127This is most useful with the
128.Fl f
129option, to replace a symlink which may point to a directory.
130.It Fl i
131Cause
132.Nm
133to write a prompt to standard error if the target file exists.
134If the response from the standard input begins with the character
135.Sq Li y
136or
137.Sq Li Y ,
138then unlink the target file so that the link may occur.
139Otherwise, do not attempt the link.
140(The
141.Fl i
142option overrides any previous
143.Fl f
144options.)
145.It Fl n
146Same as
147.Fl h ,
148for compatibility with other
149.Nm
150implementations.
151.It Fl s
152Create a symbolic link.
153.It Fl v
154Cause
155.Nm
156to be verbose, showing files as they are processed.
157.It Fl w
158Warn if the source of a symbolic link does not currently exist.
159.El
160.Pp
161By default,
162.Nm
163makes
164.Em hard
165links.
166A hard link to a file is indistinguishable from the original directory entry;
167any changes to a file are effectively independent of the name used to reference
168the file.
169Directories may not be hardlinked, and hard links may not span file systems.
170.Pp
171A symbolic link contains the name of the file to
172which it is linked.
173The referenced file is used when an
174.Xr open 2
175operation is performed on the link.
176A
177.Xr stat 2
178on a symbolic link will return the linked-to file; an
179.Xr lstat 2
180must be done to obtain information about the link.
181The
182.Xr readlink 2
183call may be used to read the contents of a symbolic link.
184Symbolic links may span file systems and may refer to directories.
185.Pp
186Given one or two arguments,
187.Nm
188creates a link to an existing file
189.Ar source_file .
190If
191.Ar target_file
192is given, the link has that name;
193.Ar target_file
194may also be a directory in which to place the link;
195otherwise it is placed in the current directory.
196If only the directory is specified, the link will be made
197to the last component of
198.Ar source_file .
199.Pp
200Given more than two arguments,
201.Nm
202makes links in
203.Ar target_dir
204to all the named source files.
205The links made will have the same name as the files being linked to.
206.Pp
207When the utility is called as
208.Nm link ,
209exactly two arguments must be supplied,
210neither of which may specify a directory.
211No options may be supplied in this simple mode of operation,
212which performs a
213.Xr link 2
214operation using the two passed arguments.
215.Sh COMPATIBILITY
216The
217.Fl h ,
218.Fl i ,
219.Fl n ,
220.Fl v
221and
222.Fl w
223options are non-standard and their use in scripts is not recommended.
224They are provided solely for compatibility with other
225.Nm
226implementations.
227.Pp
228The
229.Fl F
230option is
231.Fx
232extension and should not be used in portable scripts.
233.Sh SEE ALSO
234.Xr link 2 ,
235.Xr lstat 2 ,
236.Xr readlink 2 ,
237.Xr stat 2 ,
238.Xr symlink 2 ,
239.Xr symlink 7
240.Sh STANDARDS
241The
242.Nm
243utility conforms to
244.St -p1003.2-92 .
245.Pp
246The simplified
247.Nm link
248command conforms to
249.St -susv2 .
250.Sh HISTORY
251An
252.Nm
253command appeared in
254.At v1 .
255