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1 | .\" Copyright (c) 1994 | |
2 | .\" The Regents of the University of California. All rights reserved. | |
3 | .\" | |
4 | .\" This code is derived from software contributed to Berkeley by | |
5 | .\" Jan-Simon Pendry. | |
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 | .\" 4. Neither the name of the University nor the names of its contributors | |
16 | .\" may be used to endorse or promote products derived from this software | |
17 | .\" without specific prior written permission. | |
18 | .\" | |
19 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
20 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
21 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
22 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
23 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
24 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
25 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
26 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
27 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
28 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
29 | .\" SUCH DAMAGE. | |
30 | .\" | |
31 | .\" @(#)realpath.3 8.2 (Berkeley) 2/16/94 | |
32 | .\" $FreeBSD: src/lib/libc/stdlib/realpath.3,v 1.14 2007/01/09 00:28:10 imp Exp $ | |
33 | .\" | |
34 | .Dd April 5, 2008 | |
35 | .Dt REALPATH 3 | |
36 | .Os | |
37 | .Sh NAME | |
38 | .Nm realpath | |
39 | .Nd returns the canonicalized absolute pathname | |
40 | .\" .Sh LIBRARY | |
41 | .\" .Lb libc | |
42 | .Sh SYNOPSIS | |
43 | .In stdlib.h | |
44 | .Ft "char *" | |
45 | .Fo realpath | |
46 | .Fa "const char *restrict file_name" | |
47 | .Fa "char *restrict resolved_name" | |
48 | .Fc | |
49 | .Sh DESCRIPTION | |
50 | The | |
51 | .Fn realpath | |
52 | function resolves all symbolic links, extra | |
53 | .Dq / | |
54 | characters, and references to | |
55 | .Pa /./ | |
56 | and | |
57 | .Pa /../ | |
58 | in | |
59 | .Fa file_name . | |
60 | If the | |
61 | .Fa resolved_name | |
62 | argument | |
63 | is non-NULL, the resulting absolute pathname is copied there (it | |
64 | .Em must | |
65 | refer to a buffer capable of storing at least | |
66 | .Dv PATH_MAX | |
67 | characters). | |
68 | .Pp | |
69 | As a permitted extension to the standard, if | |
70 | .Fa resolved_name | |
71 | is NULL, | |
72 | memory is allocated for the resulting absolute pathname, and is returned by | |
73 | .Fn realpath . | |
74 | This memory should be freed by a call to | |
75 | .Xr free 3 | |
76 | when no longer needed. | |
77 | .Pp | |
78 | The | |
79 | .Fn realpath | |
80 | function will resolve both absolute and relative paths | |
81 | and return the absolute pathname corresponding to | |
82 | .Fa file_name . | |
83 | All components of | |
84 | .Fa file_name | |
85 | must exist when | |
86 | .Fn realpath | |
87 | is called. | |
88 | .Sh "RETURN VALUES" | |
89 | On success, the | |
90 | .Fn realpath | |
91 | function returns the address of the resulting absolute pathname, which is | |
92 | .Fa resolved_name | |
93 | if it was non-NULL, or the address of newly allocated memory. | |
94 | If an error occurs, | |
95 | .Fn realpath | |
96 | returns | |
97 | .Dv NULL . | |
98 | If | |
99 | .Fa resolved_name | |
100 | was non-NULL, it will | |
101 | contain the pathname which caused the problem. | |
102 | .Sh VARIANTS | |
103 | Defining | |
104 | .Dv _DARWIN_C_SOURCE | |
105 | or | |
106 | .Dv _DARWIN_BETTER_REALPATH | |
107 | before including stdlib.h will cause the provided implementation of | |
108 | .Fn realpath | |
109 | to use F_GETPATH from | |
110 | .Xr fcntl 2 | |
111 | to discover the path. | |
112 | .Sh ERRORS | |
113 | The function | |
114 | .Fn realpath | |
115 | may fail and set the external variable | |
116 | .Va errno | |
117 | for any of the errors specified for the library functions | |
118 | .Xr alloca 3 , | |
119 | .Xr getattrlist 2 , | |
120 | .Xr getcwd 3 , | |
121 | .Xr lstat 2 , | |
122 | .Xr readlink 2 , | |
123 | .Xr stat 2 , | |
124 | and | |
125 | .Xr strdup 3 . | |
126 | .\" .Sh CAVEATS | |
127 | .\" This implementation of | |
128 | .\" .Fn realpath | |
129 | .\" differs slightly from the Solaris implementation. | |
130 | .\" The | |
131 | .\" .Bx 4.4 | |
132 | .\" version always returns absolute pathnames, | |
133 | .\" whereas the Solaris implementation will, | |
134 | .\" under certain circumstances, return a relative | |
135 | .\" .Fa resolved_name | |
136 | .\" when given a relative | |
137 | .\" .Fa file_name . | |
138 | .Sh LEGACY SYNOPSIS | |
139 | .Fd #include <sys/param.h> | |
140 | .Fd #include <stdlib.h> | |
141 | .Pp | |
142 | The include file | |
143 | .In sys/param.h | |
144 | is necessary. | |
145 | .Sh LEGACY DESCRIPTION | |
146 | In legacy mode, | |
147 | the last component of | |
148 | .Fa file_name | |
149 | does not need to exist when | |
150 | .Fn realpath | |
151 | is called. | |
152 | .Sh "SEE ALSO" | |
153 | .Xr free 3 , | |
154 | .Xr getcwd 3 , | |
155 | .Xr compat 5 | |
156 | .Sh HISTORY | |
157 | The | |
158 | .Fn realpath | |
159 | function first appeared in | |
160 | .Bx 4.4 . |