(split) LDP v3.30, v3.31 の定型的な変更内容を反映。

[linuxjm/LDP_man-pages.git] / draft / man3 / popen.3

.\" Copyright 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.
.\"
.\"     @(#)popen.3     6.4 (Berkeley) 4/30/91
.\"
.\" Converted for Linux, Mon Nov 29 14:45:38 1993, faith@cs.unc.edu
.\" Modified Sat May 18 20:37:44 1996 by Martin Schulze (joey@linux.de)
.\" Modified 7 May 1998 by Joseph S. Myers (jsm28@cam.ac.uk)
.\"
.\" Japanese Version Copyright (c) 1997 Takashi Yoshino
.\"       all rights reserved.
.\" Translated 1997-01-21, Takashi Yoshino <tyoshino@eng.toyo.ac.jp>
.\" Modified 2007-05-03, Akihiro MOTOKI
.\" Modified 2008-11-09, Akihiro MOTOKI, LDP v3.13
.\"
.TH POPEN 3  2010-02-03 "GNU" "Linux Programmer's Manual"
.\"O .SH NAME
.\"O popen, pclose \- pipe stream to or from a process
.SH ̾Á°
popen, pclose \- ¥×¥í¥»¥¹¤È¤ÎÆþÎÏ/½ÐÎÏÍѤΥѥ¤¥×¡¦¥¹¥È¥ê¡¼¥à
.\"O .SH SYNOPSIS
.SH ½ñ¼°
.nf
.B #include <stdio.h>
.sp
.BI "FILE *popen(const char *" command ", const char *" type );
.sp
.BI "int pclose(FILE *" stream );
.fi
.sp
.in -4n
.\"O Feature Test Macro Requirements for glibc (see
.\"O .BR feature_test_macros (7)):
glibc ¸þ¤±¤Îµ¡Ç½¸¡ºº¥Þ¥¯¥í¤ÎÍ×·ï
.RB ( feature_test_macros (7)
»²¾È):
.ad l
.in
.sp
.BR popen (),
.BR pclose ():
.RS 4
_POSIX_C_SOURCE\ >=\ 2 || _XOPEN_SOURCE || _BSD_SOURCE || _SVID_SOURCE
.RE
.ad b
.\"O .SH DESCRIPTION
.SH ÀâÌÀ
.\"O The
.\"O .BR popen ()
.\"O function opens a process by creating a pipe, forking, and invoking the
.\"O shell.
.\"O Since a pipe is by definition unidirectional, the
.\"O .I type
.\"O argument may specify only reading or writing, not both; the resulting
.\"O stream is correspondingly read-only or write-only.
.BR popen ()
´Ø¿ô¤Ï¡¢¥×¥í¥»¥¹¤ò¥ª¡¼¥×¥ó¤¹¤ë¡£¶ñÂÎŪ¤Ë¤Ï¡¢
¥Ñ¥¤¥×¤òÀ¸À®¤·¡¢¥Õ¥©¡¼¥¯¤ò¹Ô¤¤¡¢¥·¥§¥ë¤òµ¯Æ°¤¹¤ë¡£
ÄêµÁ¤«¤éʬ¤«¤ë¤è¤¦¤Ë¡¢¥Ñ¥¤¥×¤Ï°ìÊý¸þ¤Ê¤Î¤Ç¡¢
.I type
°ú¤­¿ô¤Ë¤ÏÆɤ߹þ¤ß¤«½ñ¤­¹þ¤ß¤Î¤É¤Á¤é¤«°ìÊý¤À¤±¤ò»ØÄê¤Ç¤­¤ë
(ξÊý¤Ï»ØÄê¤Ç¤­¤Ê¤¤)¡£
À¸À®¤µ¤ì¤ë¥¹¥È¥ê¡¼¥à¤Ï¡¢¤³¤Î»ØÄê¤ËÂбþ¤·¤Æ¡¢Æɤ߼è¤êÀìÍѤޤ¿¤Ï
½ñ¤­¹þ¤ßÀìÍѤΤ¤¤º¤ì¤«¤È¤Ê¤ë¡£
.PP
.\"O The
.\"O .I command
.\"O argument is a pointer to a null-terminated string containing a shell
.\"O command line.
.\"O This command is passed to
.\"O .I /bin/sh
.\"O using the
.\"O .B \-c
.\"O flag; interpretation, if any, is performed by the shell.
.\"O The
.\"O .I type
.\"O argument is a pointer to a null-terminated string which must contain
.\"O either the letter \(aqr\(aq for reading or the letter \(aqw\(aq for writing.
.I command
°ú¤­¿ô¤Ï¡¢¥·¥§¥ë¤Î¥³¥Þ¥ó¥É¥é¥¤¥ó¤ò´Þ¤à
NULL ½ªÃ¼¤µ¤ì¤¿Ê¸»úÎó¤Ø¤Î¥Ý¥¤¥ó¥¿¤Ç¤¢¤ë¡£
¤³¤Î¥³¥Þ¥ó¥É¤Ï
.B \-c
¥Õ¥é¥°¤òÍѤ¤¤Æ
.I /bin/sh
¤ËÅϤµ¤ì¤ë¡£
¥³¥Þ¥ó¥É¤Î²ò¼á¤Ï (¤â¤·É¬Íפʤé¤Ð) ¥·¥§¥ë¤Ë¤è¤Ã¤Æ¹Ô¤ï¤ì¤ë¡£
.I type
°ú¤­¿ô¤Ï¡¢NULL ½ªÃ¼¤µ¤ì¤¿Ê¸»úÎó¤Ø¤Î¥Ý¥¤¥ó¥¿¤Ç¡¢
Æɤ߹þ¤ß¤ò¼¨¤¹Ê¸»ú \(aqr\(aq ¤«¡¢½ñ¤­¹þ¤ß¤ò¼¨¤¹Ê¸»ú \(aqw\(aq ¤Î
¤É¤Á¤é¤«°ìÊý¤ò»ØÄꤷ¤Ê¤±¤ì¤Ð¤Ê¤é¤Ê¤¤¡£
.\"O Since glibc 2.9,
.\"O this argument can additionally include the letter \(aqe\(aq,
.\"O which causes the close-on-exec flag
.\"O .RB ( FD_CLOEXEC )
.\"O to be set on the underlying file descriptor;
.\"O see the description of the
.\"O .B O_CLOEXEC
.\"O flag in
.\"O .BR open (2)
.\"O for reasons why this may be useful.
glibc 2.9 °Ê¹ß¤Ç¤Ï¡¢¤³¤Î°ú¤­¿ô¤Ëʸ»ú \(aqe\(aq ¤òÄɲäǻØÄê¤Ç¤­¤ë¡£
ʸ»ú \(aqe\(aq ¤ò»ØÄꤹ¤ë¤È¡¢
Âбþ¤¹¤ë¥Õ¥¡¥¤¥ë¥Ç¥£¥¹¥¯¥ê¥×¥¿¤Ë¤ª¤¤¤Æ¡¢
close-on-exec ¥Õ¥é¥°
.RB ( FD_CLOEXEC )
¤¬¥»¥Ã¥È¤µ¤ì¤ë¡£
¤³¤ì¤¬Ìò¤ËΩ¤ÄÍýͳ¤Ë¤Ä¤¤¤Æ¤Ï¡¢
.BR open (2)
¤Î
.B O_CLOEXEC
¥Õ¥é¥°¤ÎÀâÌÀ¤ò»²¾È¤Î¤³¤È¡£
.PP
.\"O The return value from
.\"O .BR popen ()
.\"O is a normal standard I/O stream in all respects save that it must be closed
.\"O with
.\"O .BR pclose ()
.\"O rather than
.\"O .BR fclose (3).
.BR popen ()
¤«¤é¤ÎÊÖ¤êÃͤϡ¢Ä̾ï¤Îɸ½à I/O ¥¹¥È¥ê¡¼¥à¤ÈƱ¤¸¤Ç¤¢¤ë¤¬¡¢
.BR fclose (3)
¤Ç¤Ï¤Ê¤¯
.BR pclose ()
¤ÇÊĤ¸¤Ê¤¯¤Æ¤Ï¤Ê¤é¤Ê¤¤¤³¤È¤À¤±¤¬°Û¤Ê¤ë¡£
.\"O Writing to such a stream writes to the standard input of the command; the
.\"O command's standard output is the same as that of the process that called
.\"O .BR popen (),
.\"O unless this is altered by the command itself.
.\"O Conversely, reading from a
.\"O "popened" stream reads the command's standard output, and the command's
.\"O standard input is the same as that of the process that called
.\"O .BR popen ().
¤³¤Î¥¹¥È¥ê¡¼¥à¤Ø½ñ¤­¹þ¤ó¤À·ë²Ì¤Ï¥³¥Þ¥ó¥É¤Îɸ½àÆþÎϤ˽ñ¤­¹þ¤Þ¤ì¤ë¡£
¤½¤·¤Æ¡¢¥³¥Þ¥ó¥É¤Îɸ½à½ÐÎϤϡ¢
¥³¥Þ¥ó¥É¤½¤Î¤â¤Î¤¬ÃÖ¤­´¹¤ï¤Ã¤Æ¤·¤Þ¤ï¤Ê¤¤¸Â¤ê¡¢
.BR popen ()
¤ò¸Æ¤ó¤À¥×¥í¥»¥¹¤Îɸ½à½ÐÎϤÈƱ¤¸¤³¤È¤Ë¤Ê¤ë¡£
µÕ¤Ë¡¢"popened"
.RB ( popen ()
¤Ë¤è¤Ã¤Æ³«¤«¤ì¤¿) ¥¹¥È¥ê¡¼¥à¤«¤é¤ÎÆɤ߹þ¤ß¤Ï¡¢
¤½¤Î¥³¥Þ¥ó¥É¤Îɸ½à½ÐÎϤòÆɤ߹þ¤à¤³¤È¤Ë¤Ê¤ë¡£
¤½¤·¤Æ¡¢¤½¤Î¥³¥Þ¥ó¥É¤Îɸ½àÆþÎϤÏ
.BR popen ()
¤ò¸Æ¤ó¤À¥×¥í¥»¥¹¤Îɸ½àÆþÎϤÈƱ°ì¤Ç¤¢¤ë¡£
.PP
.\"O Note that output
.\"O .BR popen ()
.\"O streams are fully buffered by default.
¥Ç¥Õ¥©¥ë¥È¤Ç¤Ï¡¢
.BR popen ()
¤Î½ÐÎÏ¥¹¥È¥ê¡¼¥à¤Ï´°Á´¤Ë¥Ð¥Ã¥Õ¥¡¥ê¥ó¥°¤µ¤ì¤ë¤³¤È¤ËÃí°Õ¤·¤è¤¦¡£
.PP
.\"O The
.\"O .BR pclose ()
.\"O function waits for the associated process to terminate and returns the exit
.\"O status of the command as returned by
.\"O .BR wait4 (2).
.BR pclose ()
´Ø¿ô¤Ï¡¢(¥Ñ¥¤¥×¤Ë) ´ØÏ¢¤Å¤±¤é¤ì¤¿¥×¥í¥»¥¹¤¬½ªÎ»¤¹¤ë¤Î¤òÂÔ¤Á¡¢
.BR wait4 (2)
¤Ë¤è¤Ã¤ÆÊÖ¤µ¤ì¤¿¥³¥Þ¥ó¥É¤Î½ªÎ»¾õÂÖ¤òÊÖ¤¹¡£
.\"O .SH "RETURN VALUE"
.SH ÊÖ¤êÃÍ
.\"O The
.\"O .BR popen ()
.\"O function returns NULL if the
.\"O .BR fork (2)
.\"O or
.\"O .BR pipe (2)
.\"O calls fail, or if it cannot allocate memory.
.BR popen ()
´Ø¿ô¤Ï¡¢
.BR fork (2)
¤Þ¤¿¤Ï
.BR pipe (2)
¸Æ¤Ó½Ð¤·¤¬¼ºÇÔ¤·¤¿¾ì¹ç¤ä¡¢
¥á¥â¥ê³ä¤êÅö¤Æ¤¬¤Ç¤­¤Ê¤«¤Ã¤¿¾ì¹ç¡¢ NULL ¤òÊÖ¤¹¡£
.PP
.\"O The
.\"O .BR pclose ()
.\"O function returns \-1 if
.\"O .\" These conditions actually give undefined results, so I commented
.\"O .\" them out.
.\"O .\" .I stream
.\"O .\" is not associated with a "popen()ed" command, if
.\"O .\".I stream
.\"O .\" already "pclose()d", or if
.\"O .BR wait4 (2)
.\"O returns an error, or some other error is detected.
.BR pclose ()
´Ø¿ô¤Ï¡¢
.BR wait4 (2)
¤¬¥¨¥é¡¼¤òÊÖ¤·¤¿¤ê¡¢²¿¤«Â¾¤Î¥¨¥é¡¼¤¬¸«¤Ä¤«¤Ã¤¿¾ì¹ç¡¢
\-1 ¤òÊÖ¤¹¡£
.\"O .SH ERRORS
.SH ¥¨¥é¡¼
.\"O The
.\"O .BR popen ()
.\"O function does not set
.\"O .I errno
.\"O if memory allocation fails.
.\"O If the underlying
.\"O .BR fork (2)
.\"O or
.\"O .BR pipe (2)
.\"O fails,
.\"O .I errno
.\"O is set appropriately.
.\"O If the
.\"O .I type
.\"O argument is invalid, and this condition is detected,
.\"O .I errno
.\"O is set to
.\"O .BR EINVAL .
.BR popen ()
´Ø¿ô¤Ï¡¢¥á¥â¥ê¥¢¥í¥±¡¼¥·¥ç¥ó¤Ë¼ºÇÔ¤·¤Æ¤â
.I errno
¤ò¥»¥Ã¥È¤·¤Ê¤¤¡£
.BR popen ()
¤¬Ãæ¤Ç¸Æ¤Ó½Ð¤¹
.BR fork (2)
¤ä
.BR pipe (2)
¤¬¼ºÇÔ¤·¤¿¾ì¹ç¤Ë¤Ï¡¢
.I errno
¤¬Å¬Àڤ˥»¥Ã¥È¤µ¤ì¤ë¡£
°ú¤­¿ô
.I type
¤¬Ìµ¸ú¤Ç¤¢¤ê¡¢¤³¤Î¾õÂÖ¤¬¸¡ÃΤµ¤ì¤¿¾ì¹ç¤Ë¤Ï¡¢
.I errno
¤¬
.B EINVAL
¤Ë¥»¥Ã¥È¤µ¤ì¤ë¡£
.PP
.\"O If
.\"O .BR pclose ()
.\"O cannot obtain the child status,
.\"O .I errno
.\"O is set to
.\"O .BR ECHILD .
.BR pclose ()
¤¬¡¢»Ò¥×¥í¥»¥¹¤Î¾õÂÖ¤ò¼èÆÀ¤Ç¤­¤Ê¤«¤Ã¤¿¾ì¹ç¡¢
.I errno
¤¬
.B ECHILD
¤Ë¥»¥Ã¥È¤µ¤ì¤ë¡£
.\"O .SH "CONFORMING TO"
.SH ½àµò
POSIX.1-2001.

.\"O The \(aqe\(aq value for
.\"O .I type
.\"O is a Linux extension.
.I type
¤Ë»ØÄê¤Ç¤­¤ë \(aqe\(aq ¤Ï Linux ¤Ç¤Î³ÈÄ¥¤Ç¤¢¤ë¡£
.\"O .SH BUGS
.SH ¥Ð¥°
.\"O Since the standard input of a command opened for reading shares its seek
.\"O offset with the process that called
.\"O .BR popen (),
.\"O if the original process has done a buffered read, the command's input
.\"O position may not be as expected.
.\"O Similarly, the output from a command
.\"O opened for writing may become intermingled with that of the original
.\"O process.
.\"O The latter can be avoided by calling
.\"O .BR fflush (3)
.\"O before
.\"O .BR popen ().
Æɤ߹þ¤ß¤Î¤¿¤á¤Ë³«¤«¤ì¤¿¥³¥Þ¥ó¥É¤Îɸ½àÆþÎϤÏ
.BR popen (),
¤ò¸Æ¤ó¤À¥×¥í¥»¥¹¤È°ì½ï¤Ë¡¢¤½¤ÎÆɤ߼è¤ê°ÌÃÖ¤ò¶¦Í­¤¹¤ë¡£
¤½¤Î¤¿¤á¡¢¤â¤È¤Î¥×¥í¥»¥¹¤¬¥Ð¥Ã¥Õ¥¡¥ê¥ó¥°¤µ¤ì¤¿Æɤ߼è¤ê¤ò½ªÎ»¤·¤¿¤é¡¢
¤½¤Î¥³¥Þ¥ó¥É¤ÎÆþÎÏ°ÌÃÖ¤ÏͽÁÛ¤µ¤ì¤¿¤â¤Î¤Ë¤Ï
¤Ê¤Ã¤Æ¤¤¤Ê¤¤¤«¤â¤·¤ì¤Ê¤¤¡£
ƱÍͤˡ¢½ñ¤­¹þ¤ß¤Î¤¿¤á¤Ë³«¤«¤ì¤¿¥³¥Þ¥ó¥É¤«¤é¤Î½ÐÎϤϡ¢
¤â¤È¤Î¥×¥í¥»¥¹¤Î½ÐÎϤȺ®¤¶¤ê¹ç¤¦¤³¤È¤Ë¤Ê¤ë¤«¤â¤·¤ì¤Ê¤¤¡£
¸å¼Ô¤Ï
.BR popen ()
¤ÎÁ°¤Ë
.BR fflush (3)
¤ò¸Æ¤Ó½Ð¤¹¤³¤È¤Ë¤è¤Ã¤Æ²óÈò²Äǽ¤Ç¤¢¤ë¡£
.PP
.\"O Failure to execute the shell is indistinguishable from the shell's failure
.\"O to execute command, or an immediate exit of the command.
.\"O The only hint is an exit status of 127.
¥·¥§¥ë¤Î¼Â¹Ô¤Î¼ºÇԤϡ¢
¥·¥§¥ë¤¬¥³¥Þ¥ó¥É¤Î¼Â¹Ô¤Ë¼ºÇÔ¤·¤¿¤³¤È¤ä¡¢
¥³¥Þ¥ó¥É¤¬¤¹¤°¤Ë½ªÎ»¤·¤Æ¤·¤Þ¤Ã¤¿¤³¤È¤È¡¢¶èÊ̤¬¤Ä¤«¤Ê¤¤¡£
Í£°ì¤Î¥Ò¥ó¥È¤Ï½ªÎ»¾õÂÖ¤¬ 127 ¤Ë¤Ê¤ë¤³¤È¤Ç¤¢¤ë¡£
.\"O .\" .SH HISTORY
.\" .SH ÍúÎò
.\"O .\" A
.\"O .\" .BR popen ()
.\"O .\" and a
.\"O .\" .BR pclose ()
.\"O .\" function appeared in Version 7 AT&T UNIX.
.\" .BR popen ()
.\" ´Ø¿ô¤È
.\" .BR pclose ()
.\" ´Ø¿ô¤Ï AT&T UNIX ¤Î Version 7 ¤«¤éƳÆþ¤µ¤ì¤¿¡£
.\"O .SH "SEE ALSO"
.SH ´ØÏ¢¹àÌÜ
.BR sh (1),
.BR fork (2),
.BR pipe (2),
.BR wait4 (2),
.BR fclose (3),
.BR fflush (3),
.BR fopen (3),
.BR stdio (3),
.BR system (3)