1 .\" Copyright (c) 1983, 1991 The Regents of the University of California.
2 .\" All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
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.
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
32 .\" @(#)readlink.2 6.8 (Berkeley) 3/10/91
34 .\" Modified Sat Jul 24 00:10:21 1993 by Rik Faith <faith@cs.unc.edu>
35 .\" Modified Tue Jul 9 23:55:17 1996 by aeb
36 .\" Modified Fri Jan 24 00:26:00 1997 by aeb
38 .\" Japanese Version Copyright (c) 1997 HANATAKA Shinya
39 .\" all rights reserved.
40 .\" Translated 1997-12-12, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
41 .\" Updated 2005-02-10, Yuichi SATO <ysato444@yahoo.co.jp>
42 .\" Updated 2006-07-19, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v2.36
43 .\" Updated 2008-08-06, Akihiro MOTOKI, LDP v3.05
45 .\"WORD: symbolic link ¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯
46 .\"WORD: buffer ¥Ð¥Ã¥Õ¥¡¡¼
48 .\"WORD: global variable ¥°¥í¡¼¥Ð¥ëÊÑ¿ô
49 .\"WORD: directory ¥Ç¥£¥ì¥¯¥È¥ê
51 .TH READLINK 2 2007-07-26 "Linux" "Linux Programmer's Manual"
54 .\"O readlink \- read value of a symbolic link
55 readlink \- ¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯¤ÎÃͤòÆɤà
58 .B #include <unistd.h>
60 .BI "ssize_t readlink(const char *" path ", char *" buf ", size_t " bufsiz );
63 .\"O Feature Test Macro Requirements for glibc (see
64 .\"O .BR feature_test_macros (7)):
65 glibc ¸þ¤±¤Îµ¡Ç½¸¡ºº¥Þ¥¯¥í¤ÎÍ×·ï
66 .RB ( feature_test_macros (7)
72 _BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500 || _POSIX_C_SOURCE\ >=\ 200112L
77 .\"O places the contents of the symbolic link
86 ¤ÇÍ¿¤¨¤é¤ì¤¿¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯¤ÎÆâÍƤò
88 ¥Ð¥Ã¥Õ¥¡¡¼¤Ø³ÊǼ¤¹¤ë¡¢
94 .\"O does not append a null byte to
100 .\"O It will truncate the contents (to a length of
102 .\"O characters), in case the buffer is too small to hold all of the contents.
103 ¤½¤ÎÆâÍÆÁ´¤Æ¤ò³ÊǼ¤¹¤ë¤Î¤Ë¥Ð¥Ã¥Õ¥¡¡¼¤¬¾®¤µ²á¤®¤ë¾ì¹ç¤Ï¡¢
105 ¥Ð¥¤¥È¤ÎŤµ¤Ë) ÆâÍƤòÀÚ¤êµÍ¤á¤ë¡£
106 .\"O .SH "RETURN VALUE"
110 .\"O returns the number of bytes placed in
112 .\"O On error, \-1 is returned and
114 .\"O is set to indicate the error.
119 ¤Ë³ÊǼ¤µ¤ì¤¿¥Ð¥¤¥È¿ô¤òÊÖ¤¹¡£
120 ¥¨¥é¡¼¤Î¾ì¹ç¡¢\-1 ¤òÊÖ¤·¡¢
122 ¤Ë¥¨¥é¡¼¤ò¼¨¤¹ÃͤòÀßÄꤹ¤ë¡£
127 .\"O Search permission is denied for a component of the path prefix.
129 .\"O .BR path_resolution (7).)
130 ¥Ñ¥¹¤Î¥Ç¥£¥ì¥¯¥È¥êÉôʬ¤Ë¸¡º÷µö²Ä¤¬Í¿¤¨¤é¤ì¤Æ¤¤¤Ê¤¤
131 .RB ( path_resolution (7)
136 .\"O extends outside the process's allocated address space.
138 ¤¬¥×¥í¥»¥¹¤Ë³ä¤êÅö¤Æ¤é¤ì¤¿¥¢¥É¥ì¥¹¶õ´Ö¤Î³°¤ò»Ø¤·¤Æ¤¤¤ë¡£
142 .\"O is not positive.
145 .\" At the glibc level, bufsiz is unsigned, so this error can only occur
146 .\" if bufsiz==0. However, the in the kernel syscall, bufsiz is signed,
147 .\" and this error can also occur if bufsiz < 0.
148 .\" See: http://thread.gmane.org/gmane.linux.man/380
149 .\" Subject: [patch 0/3] [RFC] kernel/glibc mismatch of "readlink" syscall?
152 .\"O The named file is not a symbolic link.
153 »ØÄꤷ¤¿¥Õ¥¡¥¤¥ë¤¬¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯¤Ç¤Ê¤¤¡£
156 .\"O An I/O error occurred while reading from the file system.
157 ¥Õ¥¡¥¤¥ë¡¦¥·¥¹¥Æ¥à¤ÎÆɤ߹þ¤ßÃæ¤Ë I/O ¥¨¥é¡¼¤¬µ¯¤³¤Ã¤¿¡£
160 .\"O Too many symbolic links were encountered in translating the pathname.
161 ¥Ñ¥¹Ì¾¤Ë¥·¥ó¥Ü¥ê¥Ã¥¯¡¦¥ê¥ó¥¯¤¬Â¿¤¹¤®¤ë¡£
164 .\"O A pathname, or a component of a pathname, was too long.
165 ¥Ñ¥¹Ì¾¤«¥Ñ¥¹Ì¾¤Î°ìÉôʬ¤¬Ä¹²á¤®¤ë¡£
168 .\"O The named file does not exist.
169 ¤½¤Î̾Á°¤Î¥Õ¥¡¥¤¥ë¤¬Â¸ºß¤·¤Ê¤¤¡£
172 .\"O Insufficient kernel memory was available.
173 ¥«¡¼¥Í¥ë¤Ë½½Ê¬¤Ê¥á¥â¥ê¤¬¤Ê¤¤¡£
176 .\"O A component of the path prefix is not a directory.
177 ¥Ñ¥¹¤Î¥Ç¥£¥ì¥¯¥È¥êÉôʬ¤¬¥Ç¥£¥ì¥¯¥È¥ê¤Ç¤Ê¤¤¡£
178 .\"O .SH "CONFORMING TO"
182 .\"O function call appeared in 4.2BSD),
186 ´Ø¿ô¥³¡¼¥ë¤Ï 4.2BSD ¤Ç¸½¤ï¤ì¤¿), POSIX.1-2001.
189 .\"O In versions of glibc up to and including glibc 2.4, the return type of
193 .\"O Nowadays, the return type is declared as
195 .\"O as (newly) required in POSIX.1-2001.
196 ¥Ð¡¼¥¸¥ç¥ó 2.4 °ÊÁ°¤Î glibc (¥Ð¡¼¥¸¥ç¥ó 2.4 ¤ò´Þ¤à) ¤Ç¤Ï¡¢
200 ¤ÇÀë¸À¤µ¤ì¤Æ¤¤¤¿¡£¸½ºß¤Ç¤Ï¡¢ÊÖ¤êÃͤη¿¤Ï
204 ¤Ï POSIX.1-2001 ¤Ç (¿·¤¿¤Ë) ɬ¿Ü¤È¤Ê¤Ã¤¿)¡£
211 .BR path_resolution (7),