.\" Copyright (c) 1983, 1991 The Regents of the University of California. .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)readlink.2 6.8 (Berkeley) 3/10/91 .\" .\" Modified Sat Jul 24 00:10:21 1993 by Rik Faith .\" Modified Tue Jul 9 23:55:17 1996 by aeb .\" Modified Fri Jan 24 00:26:00 1997 by aeb .\" .\" Japanese Version Copyright (c) 1997 HANATAKA Shinya .\" all rights reserved. .\" Translated 1997-12-12, HANATAKA Shinya .\" Updated 2005-02-10, Yuichi SATO .\" Updated 2006-07-19, Akihiro MOTOKI , LDP v2.36 .\" Updated 2008-08-06, Akihiro MOTOKI, LDP v3.05 .\" .\"WORD: symbolic link シンボリック・リンク .\"WORD: buffer バッファー .\"WORD: NUL ヌル文字 .\"WORD: global variable グローバル変数 .\"WORD: directory ディレクトリ .\" .TH READLINK 2 2010-09-20 "Linux" "Linux Programmer's Manual" .\"O .SH NAME .SH 名前 .\"O readlink \- read value of a symbolic link readlink \- シンボリック・リンクの値を読む .\"O .SH SYNOPSIS .SH 書式 .B #include .sp .BI "ssize_t readlink(const char *" path ", char *" buf ", size_t " bufsiz ); .sp .in -4n .\"O Feature Test Macro Requirements for glibc (see .\"O .BR feature_test_macros (7)): glibc 向けの機能検査マクロの要件 .RB ( feature_test_macros (7) 参照): .in .sp .ad l .BR readlink (): .RS 4 _BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500 || _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED || _POSIX_C_SOURCE\ >=\ 200112L .RE .ad b .\"O .SH DESCRIPTION .SH 説明 .\"O .BR readlink () .\"O places the contents of the symbolic link .\"O .I path .\"O in the buffer .\"O .IR buf , .\"O which has size .\"O .IR bufsiz . .BR readlink () は .I path で与えられたシンボリック・リンクの内容を .I buf バッファーへ格納する、 .I buf のサイズは .I bufsiz である。 .\"O .BR readlink () .\"O does not append a null byte to .\"O .IR buf . .BR readlink () は NULL バイトを .I buf に追加しない。 .\"O It will truncate the contents (to a length of .\"O .I bufsiz .\"O characters), in case the buffer is too small to hold all of the contents. その内容全てを格納するのにバッファーが小さ過ぎる場合は、 .RI ( bufsiz バイトの長さに) 内容を切り詰める。 .\"O .SH "RETURN VALUE" .SH 返り値 .\"O On success, .\"O .BR readlink () .\"O returns the number of bytes placed in .\"O .IR buf . .\"O On error, \-1 is returned and .\"O .I errno .\"O is set to indicate the error. 成功すると、 .BR readlink () は .I buf に格納されたバイト数を返す。 エラーの場合、\-1 を返し、 .I errno にエラーを示す値を設定する。 .\"O .SH ERRORS .SH エラー .TP .B EACCES .\"O Search permission is denied for a component of the path prefix. .\"O (See also .\"O .BR path_resolution (7).) パスのディレクトリ部分に検索許可が与えられていない .RB ( path_resolution (7) も参照すること)。 .TP .B EFAULT .\"O .I buf .\"O extends outside the process's allocated address space. .I buf がプロセスに割り当てられたアドレス空間の外を指している。 .TP .B EINVAL .\"O .I bufsiz .\"O is not positive. .I bufsiz が正でない。 .\" At the glibc level, bufsiz is unsigned, so this error can only occur .\" if bufsiz==0. However, the in the kernel syscall, bufsiz is signed, .\" and this error can also occur if bufsiz < 0. .\" See: http://thread.gmane.org/gmane.linux.man/380 .\" Subject: [patch 0/3] [RFC] kernel/glibc mismatch of "readlink" syscall? .TP .B EINVAL .\"O The named file is not a symbolic link. 指定したファイルがシンボリック・リンクでない。 .TP .B EIO .\"O An I/O error occurred while reading from the file system. ファイル・システムの読み込み中に I/O エラーが起こった。 .TP .B ELOOP .\"O Too many symbolic links were encountered in translating the pathname. パス名にシンボリック・リンクが多すぎる。 .TP .B ENAMETOOLONG .\"O A pathname, or a component of a pathname, was too long. パス名かパス名の一部分が長過ぎる。 .TP .B ENOENT .\"O The named file does not exist. その名前のファイルが存在しない。 .TP .B ENOMEM .\"O Insufficient kernel memory was available. カーネルに十分なメモリがない。 .TP .B ENOTDIR .\"O A component of the path prefix is not a directory. パスのディレクトリ部分がディレクトリでない。 .\"O .SH "CONFORMING TO" .SH 準拠 .\"O 4.4BSD .\"O .RB ( readlink () .\"O first appeared in 4.2BSD), .\"O POSIX.1-2001. 4.4BSD .RB ( readlink () は 4.2BSD で初めて登場した), POSIX.1-2001. .\"O .SH NOTES .SH 注意 .\"O In versions of glibc up to and including glibc 2.4, the return type of .\"O .BR readlink () .\"O was declared as .\"O .IR int . .\"O Nowadays, the return type is declared as .\"O .IR ssize_t , .\"O as (newly) required in POSIX.1-2001. バージョン 2.4 以前の glibc (バージョン 2.4 を含む) では、 .BR readlink () の返り値の型は .I int で宣言されていた。現在では、返り値の型は .I ssize_t である (返り値 .I ssize_t は POSIX.1-2001 で (新たに) 必須となった)。 .\"O .SH "SEE ALSO" .SH 関連項目 .BR lstat (2), .BR readlinkat (2), .BR stat (2), .BR symlink (2), .BR path_resolution (7), .BR symlink (7)