Import translated manuals from JM CVS Repository.

[linuxjm/jm.git] / manual / LDP_man-pages / draft / man2 / getxattr.2

.\"
.\" Extended attributes system calls manual pages
.\"
.\" Copyright (C) Andreas Gruenbacher, February 2001
.\" Copyright (C) Silicon Graphics Inc, September 2001
.\"
.\" This is free documentation; you can redistribute it and/or
.\" modify it under the terms of the GNU General Public License as
.\" published by the Free Software Foundation; either version 2 of
.\" the License, or (at your option) any later version.
.\"
.\" The GNU General Public License's references to "object code"
.\" and "executables" are to be interpreted as the output of any
.\" document formatting or typesetting system, including
.\" intermediate and printed output.
.\"
.\" This manual is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\" GNU General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public
.\" License along with this manual; if not, write to the Free
.\" Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111,
.\" USA.
.\"
.\" Japanese Version Copyright (c) 2003  Akihiro MOTOKI
.\"         all rights reserved.
.\" Translated Tue Jul  8 02:47:19 JST 2003
.\"         by Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\"
.\"WORD:        extended attributes     ³Èĥ°À­
.\"WORD:        namespace               ̾Á°¶õ´Ö
.\"
.TH GETXATTR 2 2001-12-01 "Linux" "Linux Programmer's Manual"
.\"O .SH NAME
.\"O getxattr, lgetxattr, fgetxattr \- retrieve an extended attribute value
.SH ̾Á°
getxattr, lgetxattr, fgetxattr \- ³Èĥ°À­¤ÎÃͤò¼èÆÀ¤¹¤ë
.\"O .SH SYNOPSIS
.SH ½ñ¼°
.fam C
.nf
.B #include <sys/types.h>
.B #include <attr/xattr.h>
.sp
.BI "ssize_t getxattr(const char\ *" path ", const char\ *" name ,
.BI "                 void\ *" value ", size_t " size );
.BI "ssize_t lgetxattr(const char\ *" path ", const char\ *" name ,
.BI "                 void\ *" value ", size_t " size );
.BI "ssize_t fgetxattr(int " fd ", const char\ *" name ,
.BI "                 void\ *" value ", size_t " size );
.fi
.fam T
.\"O .SH DESCRIPTION
.SH ÀâÌÀ
.\"O Extended attributes are
.\"O .IR name :\c
.\"O .I value
.\"O pairs associated with inodes (files, directories, symbolic links, etc.).
.\"O They are extensions to the normal attributes which are associated
.\"O with all inodes in the system (i.e., the
.\"O .BR stat (2)
.\"O data).
.\"O A complete overview of extended attributes concepts can be found in
.\"O .BR attr (5).
³Èĥ°À­¤Ï¡¢inode (¥Õ¥¡¥¤¥ë¡¢¥Ç¥£¥ì¥¯¥È¥ê¡¢¥·¥ó¥Ü¥ê¥Ã¥¯¥ê¥ó¥¯Åù) ¤Ë
´ØÏ¢ÉÕ¤±¤é¤ì¤¿
.IR name :\c
.I value
¤ÎÂФǤ¢¤ë¡£
¤³¤ì¤é¤Ï¡¢¥·¥¹¥Æ¥à¾å¤Î¤¹¤Ù¤Æ¤Î inode ¤Ë´ØÏ¢ÉÕ¤±¤é¤ì¤¿Ä̾ï¤Î°À­
.RB ( stat (2)
¤¬ÊÖ¤¹¥Ç¡¼¥¿) ¤ò³ÈÄ¥¤¹¤ë¤â¤Î¤Ç¤¢¤ë¡£
³Èĥ°À­¤Î¥³¥ó¥»¥×¥È¤Ï
.BR attr (5)
¤Ë½ñ¤«¤ì¤Æ¤¤¤ë¡£
.PP
.\"O .BR getxattr ()
.\"O retrieves the
.\"O .I value
.\"O of the extended attribute identified by
.\"O .I name
.\"O and associated with the given
.\"O .I path
.\"O in the file system.
.\"O The length of the attribute
.\"O .I value
.\"O is returned.
.BR getxattr ()
¤Ï¡¢¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥àÆâ¤Î»ØÄꤵ¤ì¤¿
.I path
¤ËÂбþ¤¹¤ë¡¢Ì¾Á°
.I name
¤Î³Èĥ°À­¤Î
.I value
(ÃÍ) ¤ò¼èÆÀ¤¹¤ë¡£
°À­
.I value
¤ÎŤµ¤¬ÊÖ¤µ¤ì¤ë¡£
.PP
.\"O .BR lgetxattr ()
.\"O is identical to
.\"O .BR getxattr (),
.\"O except in the case of a symbolic link, where the link itself is
.\"O interrogated, not the file that it refers to.
.BR lgetxattr ()
¤Ï
.BR getxattr ()
¤ÈƱ¤¸¤À¤¬¡¢¥·¥ó¥Ü¥ê¥Ã¥¯¥ê¥ó¥¯¤Î¾ì¹ç¤Ë¡¢¥ê¥ó¥¯¤¬»²¾È¤·¤Æ¤¤¤ë¥Õ¥¡¥¤¥ë
¤Ç¤Ï¤Ê¤¯¡¢¥ê¥ó¥¯¤½¤Î¤â¤Î¤Î¾ðÊó¤ò¼èÆÀ¤¹¤ëÅÀ¤À¤±¤¬°Û¤Ê¤ë¡£
.PP
.\"O .BR fgetxattr ()
.\"O is identical to
.\"O .BR getxattr (),
.\"O only the open file referred to by
.\"O .I fd
.\"O (as returned by
.\"O .BR open (2))
.\"O is interrogated in place of
.\"O .IR path .
.BR fgetxattr ()
¤Ï
.BR getxattr ()
¤ÈƱ¤¸¤À¤¬¡¢
.I path
¤ÎÂå¤ï¤ê¤Ë
.I fd
¤Ç»²¾È¤µ¤ì¤¿¥ª¡¼¥×¥óºÑ¤ß¥Õ¥¡¥¤¥ë¤Î¾ðÊó¤À¤±¤ò¼èÆÀ¤¹¤ëÅÀ¤¬°Û¤Ê¤ë
.RI ( fd
¤Ï
.BR open (2)
¤Ë¤è¤Ã¤ÆÊÖ¤µ¤ì¤ë)¡£
.PP
.\"O An extended attribute
.\"O .I name
.\"O is a simple null-terminated string.
.\"O The name includes a namespace prefix; there may be several, disjoint
.\"O namespaces associated with an individual inode.
.\"O The value of an extended attribute is a chunk of arbitrary textual or
.\"O binary data of specified length.
³Èĥ°À­¤Î̾Á°
.I name
¤ÏÉáÄ̤ΠNULL ½ªÃ¼¤µ¤ì¤¿Ê¸»úÎó¤Ç¤¢¤ë¡£
̾Á°¤Ë¤Ï¡¢Ì¾Á°¶õ´Ö¤òɽ¤¹ÀÜƬ¼­ (prefix) ¤¬´Þ¤Þ¤ì¤ë;
¸Ä¡¹¤Î inode ¤ËÂФ·¤Æ¡¢¸ß¤¤¤ËÆÈΩ¤Ê̾Á°¶õ´Ö¤¬Ê£¿ô¤¢¤Ã¤Æ¤â¤è¤¤¡£
³Èĥ°À­¤ÎÃͤϡ¢¤¢¤ë°ìÄê¤ÎŤµ¤ÎǤ°Õ¤Î¥Æ¥­¥¹¥È¡¦¥Ç¡¼¥¿¤Þ¤¿¤Ï
¥Ð¥¤¥Ê¥ê¡¦¥Ç¡¼¥¿¤Î½¸¹ç¤Ç¤¢¤ë¡£
.PP
.\"O An empty buffer of
.\"O .I size
.\"O zero can be passed into these calls to return the current size of the
.\"O named extended attribute, which can be used to estimate the size of a
.\"O buffer which is sufficiently large to hold the value associated with
.\"O the extended attribute.
.I size
¤Ë 0 ¤ò»ØÄꤷ¤Æ¶õ¤Î¥Ð¥Ã¥Õ¥¡¤ò¤³¤ì¤é¤Î¥·¥¹¥Æ¥à¥³¡¼¥ë¤ËÅϤ¹¤³¤È¤¬¤Ç¤­¡¢
¤³¤Î¾ì¹ç¤Ë¤Ï»ØÄꤵ¤ì¤¿Ì¾Á°¤Î³Èĥ°À­¤Î¸½ºß¤Î¥µ¥¤¥º¤¬ÊÖ¤µ¤ì¤ë¡£
¤³¤ÎÊýË¡¤Ï¡¢³Èĥ°À­¤ÎÃͤòÊÝ»ý¤¹¤ë¤Î¤Ë½½Ê¬¤ÊÂ礭¤µ¤Î¥Ð¥Ã¥Õ¥¡¡¦¥µ¥¤¥º¤ò
¸«ÀѤâ¤ë¤Î¤Ë»È¤¦¤³¤È¤¬¤Ç¤­¤ë¡¢
.PP
.\"O The interface is designed to allow guessing of initial buffer
.\"O sizes, and to enlarge buffers when the return value indicates
.\"O that the buffer provided was too small.
¤³¤Î¥·¥¹¥Æ¥à¥³¡¼¥ë¡¦¥¤¥ó¥¿¥Õ¥§¡¼¥¹¤Ï¡¢½é´ü¥Ð¥Ã¥Õ¥¡¤Î¥µ¥¤¥º¤Î¿ä¬¤ò¤·¤¿¤ê¡¢
Í¿¤¨¤é¤ì¤¿¥Ð¥Ã¥Õ¥¡¤¬¾®¤µ¤¹¤®¤¿¤³¤È¤òÊÖ¤êÃͤÇÃΤ餻¤ë¤³¤È¤Ç¥Ð¥Ã¥Õ¥¡¤òÂ礭¤¯
¤·¤¿¤ê¤Ç¤­¤ë¤è¤¦¤ËÀ߷פµ¤ì¤Æ¤¤¤ë¡£
.\"O .SH RETURN VALUE
.SH ÊÖ¤êÃÍ
.\"O On success, a positive number is returned indicating the size of the
.\"O extended attribute value.
.\"O On failure, \-1 is returned and
.\"O .I errno
.\"O is set appropriately.
À®¸ù¤·¤¿¾ì¹ç¡¢³Èĥ°À­¤ÎÃͤÎŤµ¤òɽ¤¹Àµ¤Î¿ô¤¬ÊÖ¤µ¤ì¤ë¡£
¼ºÇÔ¤·¤¿¾ì¹ç¡¢ \-1 ¤¬ÊÖ¤µ¤ì¡¢
.I errno
¤ËŬÀÚ¤ÊÃͤ¬¥»¥Ã¥È¤µ¤ì¤ë¡£
.PP
.\"O If the named attribute does not exist, or the process has no access to
.\"O this attribute,
.\"O .I errno
.\"O is set to
.\"O .BR ENOATTR .
»ØÄꤵ¤ì¤¿Ì¾Á°¤Î°À­¤¬Â¸ºß¤·¤Ê¤¤¾ì¹ç¡¢¤Þ¤¿¤Ï¥×¥í¥»¥¹¤¬¤½¤Î°À­¤Ë¥¢¥¯¥»¥¹
¤¹¤ë¸¢¸Â¤¬¤Ê¤¤¾ì¹ç¡¢
.I errno
¤Ë
.B ENOATTR
¤¬¥»¥Ã¥È¤µ¤ì¤ë¡£
.PP
.\"O If the
.\"O .I size
.\"O of the
.\"O .I value
.\"O buffer is too small to hold the result,
.\"O .I errno
.\"O is set to
.\"O .B ERANGE .
.I value
¥Ð¥Ã¥Õ¥¡¤ÎÂ礭¤µ
.I size
¤¬·ë²Ì¤òÊÝ»ý¤¹¤ë¤Î¤Ë½½Ê¬¤ÊÂ礭¤µ¤Ç¤Ê¤¤¾ì¹ç¡¢
.I errno
¤Ë
.B ERANGE
¤¬¥»¥Ã¥È¤µ¤ì¤ë¡£
.PP
.\"O If extended attributes are not supported by the file system, or are disabled,
.\"O .I errno
.\"O is set to
.\"O .B ENOTSUP .
³Èĥ°À­¤¬¤½¤Î¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Ç¥µ¥Ý¡¼¥È¤µ¤ì¤Æ¤¤¤Ê¤¤¾ì¹ç¡¢
¤â¤·¤¯¤Ï̵¸ú¤Ë¤Ê¤Ã¤Æ¤¤¤ë¾ì¹ç¡¢
.I errno
¤Ë
.B ENOTSUP
¤¬¥»¥Ã¥È¤µ¤ì¤ë¡£
.PP
.\"O The errors documented for the
.\"O .BR stat (2)
.\"O system call are also applicable here.
.BR stat (2)
¥·¥¹¥Æ¥à¥³¡¼¥ë¤ÎÀâÌÀ¤Ë½ñ¤«¤ì¤Æ¤¤¤ë¥¨¥é¡¼¤Ï
¤³¤ì¤é¤Î¥·¥¹¥Æ¥à¥³¡¼¥ë¤Ë¤âŬÍѤµ¤ì¤ë¡£
.\"O .SH VERSIONS
.SH ¥Ð¡¼¥¸¥ç¥ó
.\"O These system calls have been available on Linux since kernel 2.4;
.\"O glibc support is provided since version 2.3.
¤³¤ì¤é¤Î¥·¥¹¥Æ¥à¥³¡¼¥ë¤Ï¥«¡¼¥Í¥ë 2.4 °Ê¹ß¤Î Linux ¤ÇÍøÍѤǤ­¤ë¡£
glibc ¤Ç¤Î¥µ¥Ý¡¼¥È¤Ï¥Ð¡¼¥¸¥ç¥ó 2.3 °Ê¹ß¤Ç¹Ô¤ï¤ì¤Æ¤¤¤ë¡£
.\"O .SH "CONFORMING TO"
.SH ½àµò
.\"O These system calls are Linux-specific.
¤³¤ì¤é¤Î¥·¥¹¥Æ¥à¥³¡¼¥ë¤Ï Linux Æȼ«¤Ç¤¢¤ë¡£
.\"O .\" .SH AUTHORS
.\" .SH Ãø¼Ô
.\"O .\" Andreas Gruenbacher,
.\"O .\" .RI < a.gruenbacher@computer.org >
.\"O .\" and the SGI XFS development team,
.\"O .\" .RI < linux-xfs@oss.sgi.com >.
.\"O .\" Please send any bug reports or comments to these addresses.
.\" Andreas Gruenbacher,
.\" .RI < a.gruenbacher@computer.org >
.\" ¤È SGI XFS ³«È¯¥Á¡¼¥à,
.\" .RI < linux-xfs@oss.sgi.com >¡£
.\" ¥Ð¥°¥ì¥Ý¡¼¥È¤ä¥³¥á¥ó¥È¤Ï¾åµ­¤Î¥¢¥É¥ì¥¹¤Þ¤ÇÁ÷¤Ã¤Æ²¼¤µ¤¤¡£
.\"O .SH SEE ALSO
.SH ´ØÏ¢¹àÌÜ
.BR getfattr (1),
.BR setfattr (1),
.BR listxattr (2),
.BR open (2),
.BR removexattr (2),
.BR setxattr (2),
.BR stat (2),
.BR attr (5),
.BR symlink (7)