.\" Hey Emacs! This file is -*- nroff -*- source.
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.\" Copyright (C) 2005, 2008, Michael Kerrisk <mtk.manpages@gmail.com>
.\" (A few fragments remain from an earlier (1992) version by
.\" Drew Eckhardt <drew@cs.colorado.edu>.)
.\"
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.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
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.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
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.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
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.\" which is licensed free of charge, as they might when working
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.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" Modified by Michael Haardt <michael@moria.de>
.\" Modified 1993-07-23 by Rik Faith <faith@cs.unc.edu>
.\" Modified 1996-10-22 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified 2004-06-17 by Michael Kerrisk <mtk.manpages@gmail.com>
.\" Modified 2005, mtk: added an example program
.\" Modified 2008-01-09, mtk: rewrote DESCRIPTION; minor additions
.\"     to EXAMPLE text.
.\" 2008-10-10, mtk: add description of pipe2()
.\"
.\" Japanese Version Copyright (c) 1997 SUTO, Mitsuaki
.\"         all rights reserved.
.\" Translated Thu Jun 26 21:09:51 JST 1997
.\"         by SUTO, Mitsuaki <suto@av.crl.sony.co.jp>
.\" Updated & Modified Thu Feb 10 00:47:11 JST 2005
.\"         by Yuichi SATO <ysato444@yahoo.co.jp>
.\" Updated & Modified Sat Dec 17 08:10:16 JST 2005 by Yuichi SATO
.\" Updated 2008-02-10, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v2.77
.\" Updated 2008-11-09, Akihiro MOTOKI, LDP v3.13
.\"
.TH PIPE 2 2008-11-04 "Linux" "Linux Programmer's Manual"
.SH ̾
pipe, pipe2 \- ѥפ
.SH 
.nf
.B #include <unistd.h>
.sp
.BI "int pipe(int " pipefd "[2]);"
.sp
.B #define _GNU_SOURCE
.B #include <unistd.h>
.sp
.BI "int pipe2(int " pipefd "[2], int " flags );
.fi
.SH 
.BR pipe (2)
ϥѥפ롣
ѥפϡץ̿˻ѤǤñΥǡͥǤ롣

.I pipefd
ϡѥפξü򻲾ȤĤΥեǥץ
֤Τ˻Ѥ롣
.I pipefd[0]
ѥפɤ߽Ф¦
.I pipefd[1]
ѥפν񤭹¦Ǥ롣
ѥפν񤭹¦˽񤭹ޤ줿ǡϡ
ѥפɤ߽Ф¦ɤ߽ФޤǥͥǥХåե󥰤롣
ʤܺ٤
.BR pipe (7)
򻲾ȤΤȡ

.BR pipe2 ()

.I flags
 0 ξˤ
.BR pipe ()
ƱǤ롣
.I flags
˰ʲͤӥå (OR) ǻꤹ뤳Ȥǡ
ۤʤư򤵤뤳ȤǤ롣
.TP 12
.B O_NONBLOCK
ĤΥץե뵭 (open file description) 
.B O_NONBLOCK
ե륹ơե饰򥻥åȤ롣
Υե饰ȤȤǡ
.B O_NONBLOCK
򥻥åȤ뤿
.BR fcntl (2)
ɲäǸƤӽФɬפʤʤ롣
.TP
.B O_CLOEXEC
ĤΥեǥץ
close-on-exec
.RB ( FD_CLOEXEC )
ե饰򥻥åȤ롣
Υե饰ΩͳˤĤƤϡ
.BR open (2)

.B O_CLOEXEC
ե饰򻲾ȤΤȡ
.SH ֤
 0 ֤롣Ԥ \-1 ֤ꡢ
.I errno
顼Ƥ˽äꤵ롣
.SH 顼
.TP
.B EFAULT
.I pipefd
̵ͤǤ롣
.TP
.B EINVAL
.RB ( pipe2 ())
.I flags
̵ͤäƤ롣
.TP
.B EMFILE
ΥץǻȤƤեǥץ¿롣
.TP
.B ENFILE
ץ󤵤Ƥեƥ¤ã
.SH С
.BR pipe2 ()
ϥС 2.6.27  Linux ɲä줿
glibc ˤ륵ݡȤϥС 2.9 ʹߤѤǤ롣
.SH 
.BR pipe ():
POSIX.1-2001.

.BR pipe2 ()
 Linux ͭǤ롣
.SH 
.\" fork.2 ϤΥץ򻲾ȤƤ롣
ʲΥץǤϥѥפθ
.BR fork (2)
ǻҥץ롣
ҥץƱѥפ򻲾ȤեǥץΥԡ
Ѿ롣
.BR fork (2)
θ塢ƥץϥѥ
.RB ( pipe (7)
򻲾) ɬפʤʤäǥץ򥯥롣
ƥץϥץΥޥɥ饤˴ޤޤ
ʸѥפؽ񤭹ߡ
ҥץϤʸѥפ 1 ХȤɤ߹ɸϤ˥롣
.nf

#include <sys/wait.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

int
main(int argc, char *argv[])
{
    int pipefd[2];
    pid_t cpid;
    char buf;

    assert(argc == 2);

    if (pipe(pipefd) == \-1) {
        perror("pipe");
        exit(EXIT_FAILURE);
    }

    cpid = fork();
    if (cpid == \-1) {
        perror("fork");
        exit(EXIT_FAILURE);
    }

    if (cpid == 0) {    /* ҥץѥפɤ߹ */
        close(pipefd[1]);  /* Ѥʤ write ¦ϥ */

        while (read(pipefd[0], &buf, 1) > 0)
            write(STDOUT_FILENO, &buf, 1);

        write(STDOUT_FILENO, "\\n", 1);
        close(pipefd[0]);
        _exit(EXIT_SUCCESS);

    } else {            /* ƥץ argv[1] ѥפؽ񤭹 */
        close(pipefd[0]);          /* Ѥʤ read ¦ϥ */
        write(pipefd[1], argv[1], strlen(argv[1]));
        close(pipefd[1]);          /* ɤ߹¦ EOF ˽в */
        wait(NULL);                /* ҥץԤ */
        exit(EXIT_SUCCESS);
    }
}
.fi
.SH Ϣ
.BR fork (2),
.BR read (2),
.BR socketpair (2),
.BR write (2),
.BR popen (3),
.BR pipe (7)