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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 .TH READLINK 2 2010-09-20 "Linux" "Linux Programmer's Manual"
40 readlink \- read value of a symbolic link
42 .B #include <unistd.h>
44 .BI "ssize_t readlink(const char *" path ", char *" buf ", size_t " bufsiz );
47 Feature Test Macro Requirements for glibc (see
48 .BR feature_test_macros (7)):
54 _BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500 ||
55 _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED || _POSIX_C_SOURCE\ >=\ 200112L
60 places the contents of the symbolic link
67 does not append a null byte to
69 It will truncate the contents (to a length of
71 characters), in case the buffer is too small to hold all of the contents.
75 returns the number of bytes placed in
77 On error, \-1 is returned and
79 is set to indicate the error.
83 Search permission is denied for a component of the path prefix.
85 .BR path_resolution (7).)
89 extends outside the process's allocated address space.
94 .\" At the glibc level, bufsiz is unsigned, so this error can only occur
95 .\" if bufsiz==0. However, the in the kernel syscall, bufsiz is signed,
96 .\" and this error can also occur if bufsiz < 0.
97 .\" See: http://thread.gmane.org/gmane.linux.man/380
98 .\" Subject: [patch 0/3] [RFC] kernel/glibc mismatch of "readlink" syscall?
101 The named file is not a symbolic link.
104 An I/O error occurred while reading from the file system.
107 Too many symbolic links were encountered in translating the pathname.
110 A pathname, or a component of a pathname, was too long.
113 The named file does not exist.
116 Insufficient kernel memory was available.
119 A component of the path prefix is not a directory.
123 first appeared in 4.2BSD),
126 In versions of glibc up to and including glibc 2.4, the return type of
130 Nowadays, the return type is declared as
132 as (newly) required in POSIX.1-2001.
138 .BR path_resolution (7),