.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" Copyright (c) 1993 by Thomas Koenig <ig25@rz.uni-karlsruhe.de>
.\" and Copyright (c) 2004 by Michael Kerrisk <mtk.manpages@gmail.com>
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" 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.\" manual page may be incorrect or out-of-date.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
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\" License.
.\"
.\" Modified Sat Jul 24 13:30:06 1993 by Rik Faith <faith@cs.unc.edu>
.\" Modified Sun Aug 21 17:42:42 1994 by Rik Faith <faith@cs.unc.edu>
.\"          (Thanks to Koen Holtman <koen@win.tue.nl>)
.\" Modified Wed May 17 15:54:12 1995 by Rik Faith <faith@cs.unc.edu>
.\"           To remove *'s from status in macros (Thanks to Michael Shields).
.\" Modified as suggested by Nick Duffek <nsd@bbc.com>, aeb, 960426
.\" Modified Mon Jun 23 14:09:52 1997 by aeb - add EINTR.
.\" Modified Thu Nov 26 02:12:45 1998 by aeb - add SIGCHLD stuff.
.\" Modified Mon Jul 24 21:37:38 2000 by David A. Wheeler
.\"          <dwheeler@dwheeler.com> - noted thread issues.
.\" Modified 26 Jun 01 by Michael Kerrisk
.\"          Added __WCLONE, __WALL, and __WNOTHREAD descriptions
.\" Modified 2001-09-25, aeb
.\" Modified 26 Jun 01 by Michael Kerrisk, <mtk.manpages@gmail.com>
.\"	Updated notes on setting disposition of SIGCHLD to SIG_IGN
.\" 2004-11-11, mtk
.\"	Added waitid(2); added WCONTINUED and WIFCONTINUED()
.\"	Added text on SA_NOCLDSTOP
.\"	Updated discussion of SA_NOCLDWAIT to reflect 2.6 behavior
.\"	Much other text rewritten
.\" 2005-05-10, mtk, __W* flags can't be used with waitid()
.\"
.\" Japanese Version Copyright (c) 1997 HANATAKA Shinya all rights reserved.
.\" Japanese Version Copyright (c) 2005 Akihiro MOTOKI all rights reserved.
.\" Translated 1997-03-04, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Modified 2000-09-23, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Updated 2001-06-25, Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2001-10-15, Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2001-12-13, Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2002-10-21, Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2003-01-27, Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2003-09-12, Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2005-03-19, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" Updated 2005-12-26, Akihiro MOTOKI
.\"
.\"WORD:	signal handling		ʥ
.\"WORD:	suspend			(suspend)
.\"WORD:	zombie			(zombie)
.\"WORD:	child process		ҥץ
.\"WORD:	process group		ץ롼
.\"WORD:	process group ID	ץ롼ID
.\"WORD:	stop			(stop)
.\"WORD:	effective user ID	¸桼ID
.\"WORD:	block			ػ(block)
.\"
.TH WAIT 2  2007-07-26 "Linux" "Linux Programmer's Manual"
.SH ̾
wait, waitpid, waitid \- ץξѲԤ
.SH 
.B #include <sys/types.h>
.br
.B #include <sys/wait.h>
.sp
.BI "pid_t wait(int *" "status" );

.BI "pid_t waitpid(pid_t " pid ", int *" status ", int " options );

.BI "int waitid(idtype_t " idtype ", id_t " id \
", siginfo_t *" infop ", int " options );
.sp
.in -4n
glibc εǽޥ׷
.RB ( feature_test_macros (7)
):
.in
.sp
.BR waitid ():
_SVID_SOURCE || _XOPEN_SOURCE
.SH 
ΥƥॳϤ⡢ƤӽФץλҥץ
ѲԤ֤ѲλҥץξΤ
Ѥ롣
ѲȤϰʲΤ줫Ǥ:
ҥץνλʥˤҥץߡ
ʥˤҥץκƳ
ҥץλϡwait ¹Ԥ뤳Ȥǡ
ƥबλҥץ˴Ϣ꥽Ǥ褦ˤʤ롣
wait ¹Ԥʤäˤϡλҥץ
֥ӡ׾֤ǻĤ³ (դξϤ򻲾ȤΤ)

ҥץξѲǤȯƤ硢Υ
롣ʳξϡҥץξѲ뤫
ʥϥɥˤꥷƥॳ뤬Ǥޤǡ
 (block)  (Ԥϡ
.BR sigaction (2)

.B SA_RESTART
ե饰ˤꥷƥॳ뤬ưŪ˺ƥȤ褦ˤʤäƤʤ
ưǤ)
ʲǤϡѲäΥƥॳΤ줫
äԤƤʤҥץ
.I waitable
(Ԥǽ) ȸƤ֡
.SS "wait()  waitpid()"
.BR wait ()
ƥॳϡҥץΤ줫λޤ
ƤӽФΥץμ¹Ԥߤ롣
ʲĤθƤӽФǤ:
.nf

    wait(&status);

    waitpid(\-1, &status, 0);
.fi

.BR waitpid ()
ƥॳϡ
.I pid
ǻꤷҥץξѲޤǡ
ƤӽФΥץμ¹Ԥߤ롣ǥեȤǤϡ
.BR waitpid ()
ϻҥץνλԤĤư
.I options
ˤѹǽǤ롣

.I pid
˻Ǥͤϰʲ̤:
.IP "< \-1"
ץ롼ID 
.I pid
ͤҥץΤ줫λޤǤԤġ
.IP \-1
ҥץΤɤ줫λޤԤġ
.IP 0
ץ롼ID ƤӽФץΤΤ
ҥץԤġ
.IP "> 0"
ץID 
.I pid
ҥץԤġ
.PP
.I options
ͤϼ 0 İʾ¤Ǥ:
.TP 12
.B WNOHANG
Ѳäҥץʤˤ롣
.TP
.B WUNTRACED
ҥץߤˤ (ҥץ
.BR ptrace (2)
ǥȥ졼ƤϽ)
Υץ󤬻ꤵƤʤǤ⡢ߤץ
֥ȥ졼 (traced)פƤСҥץξ֤𤵤롣
.TP
.B WCONTINUED
(Linux 2.6.10 ʹ)
ߤҥץ
.B SIGCONT
ˤƳˤ롣
.PP
(Linux ѥץˤĤƤϸҤ)
.PP
.B WUNTRACED

.B WCONTINUED
ξץͭȤʤΤϡ
.B SIGCHLD
ʥФ
.B SA_NOCLDSTOP
ե饰ꤵƤʤǤ
.RB ( sigaction (2)
򻲾)
.PP
.I status
 NULL ǤʤС
.BR wait ()

.BR waitpid ()

.I status
ǻؤ \fIint\fP ˾־Ǽ롣
ϰʲΥޥȤäƸǤ롣
(Υޥΰˤϡ
.BR wait ()

.BR waitpid ()
񤭹ΤΤꤹ롣ݥ󥿤ǤϤʤ!)
.TP
.BI WIFEXITED( status )
ҥץ˽λ˿֤
ˡפȤϡ
.BR exit (3)

.BR _exit (2)
ƤӽФ줿硢⤷
main() Ǥ롣
.TP
.BI WEXITSTATUS( status )
ҥץνλơ֤
λơ
.I status
β 8ӥåȤǹƤꡢ
.BR exit (3)

.BR _exit (2)
θƤӽФϤ줿͡⤷ main()  return ʸ
Ȥƻꤵ줿ͤǤ롣
ΥޥѤΤ
.B WIFEXITED
֤ˤ٤Ǥ롣
.TP
.BI WIFSIGNALED( status )
ҥץʥˤ꽪λ˿֤
.TP
.BI WTERMSIG( status )
ҥץλθȤʤäʥֹ֤
ΥޥѤΤ
.B WIFSIGNALED
֤ˤ٤Ǥ롣
.TP
.BI WCOREDUMP( status )
ҥץפ˿֤
ΥޥѤΤ
.B WIFSIGNALED
֤ˤ٤Ǥ롣
Υޥ POSIX.1-2001 ǤϵꤵƤ餺
(AIX, SunOS ʤɤ) Ĥ Unix μǤѤǤʤ
ɬ #ifdef WCOREDUMP ... #endif dzäƻѤ뤳ȡ
.TP
.BI WIFSTOPPED( status )
ҥץʥˤߤ˿֤
줬ˤʤΤϡƥॳ뤬
.B WUNTRACED
ꤷƸƤӽФ줿礫ҥץȥ졼Ƥ
.RB ( ptrace (2)
) Ǥ롣
.TP
.BI WSTOPSIG( status )
ҥץߤʥֹ֤
ΥޥѤΤ
.B WIFSTOPPED
 0 ʳ֤ˤ٤Ǥ롣
.TP
.BI WIFCONTINUED( status )
(Linux 2.6.10 ʹ)
ҥץ
.B SIGCONT
ˤƳ˿֤
.SS "waitid()"
.BR waitid ()
ƥॳ (Linux 2.6.9 ʹߤѲǽ) Ȥȡ
ҥץΤɤξѲԤĤˤĤƤ٤椬Ǥ롣


.I idtype

.I id
ǤɤλҥץԤĤ򤹤:
.IP "\fIidtype\fP == \fBP_PID\fP"
ץID 
.I id
ȰפҥץԤġ
.IP "\fIidtype\fP == \fBP_PGID\fP"
ץ롼ID 
.I id
ȰפҥץԤġ
.IP "\fIidtype\fP == \fBP_ALL\fP"
ҥץоݤԤġ
.I id
̵뤵롣
.PP
ҥץΤɤξѲԤĤϰʲΥե饰ǻꤹ
.RI ( options
ˤ 1İʾΥե饰¤Ȥäƻꤹ):
.TP 12
.B WEXITED
ҥץνλԤġ
.TP
.B WSTOPPED
ҥץʥˤߤΤԤġ
.TP
.B WCONTINUED
(ߤƤ) ҥץ
.B SIGCONT
ƺƳΤԤġ
.PP
˰ʲΥե饰¤η
.I options
˻Ǥ:
.TP 12
.B WNOHANG
.BR waitpid ()
Ʊ͡
.TP
.B WNOWAIT
waitable ֤Υץ򤽤Τޤޤˤ롣θ wait 
ȤäơƱҥץξ־⤦ټ뤳ȤǤ롣
.PP
ˤϡ
.BR waitid ()

.I infop
ؤ
.I siginfo_t
¤ΤΰʲΥեɤꤹ:
.TP 12
\fIsi_pid\fP
ҥץΥץID
.TP
\fIsi_uid\fP
ҥץμ¥桼ID
(Υեɤ¾ΤۤȤɤμǤꤵʤ)
.TP
\fIsi_signo\fP

.B SIGCHLD
ꤵ롣
.TP
\fIsi_status\fP
.BR _exit (2)
(
.BR exit (3))
˻ꤵ줿ҥץνλơ⤷
ҥץνλߡƳθȤʤäʥ뤬ꤵ롣
Υեɤɤ᤹뤫ϡ
.I si_code
եɤ򻲾ȤƷ뤳ȤǤ롣
.TP
\fIsi_code\fP
ʲΤ줫ꤵ:
.B CLD_EXITED
(ҥץ
.BR _exit (2)
ƤӽФ);
.B CLD_KILLED
(ʥˤҥץ kill 줿);
.B CLD_STOPPED
(ʥˤҥץߤ);
.B CLD_CONTINUED
.RB ( SIGCONT
ˤҥץƳ줿)
.PP
.B WNOHANG

.I options
˻ꤵƤơ
waitable ֤λҥץʤäˤϡ
.BR waitid ()
Ϥ 0 ֤ΤȤ
.I infop
ؤ
.I siginfo_t
¤ΤƤǤ롣
.\" POSIX.1-2001 ǤϡβǽĤƤ롣
.\" (Linux ޤ) ۤȤɤμǤϡξ˹¤Τ 0 뤬
.\" ʤȤĤμ (AIX 5.1) ǤϤʤʤ -- MTK Nov 04
ξ waitable ֤λҥץäȶ̤ˤϡ
.BR waitid ()
ƤӽФ
.I si_pid
 0 ˤƤ뤬ǤΥեɤ 0 ʳͤɤ
åФ褤
.SH ֤
.BR wait ():
ȡλҥץΥץID ֤
顼ξ \-1 ֤

.BR waitpid ():
ȡ֤ѲҥץΥץID ֤
.B WNOHANG
ꤵƤơ
.I pid
ǻؼ줿ҥץİʾ¸ߤ뤬ɤλҥץǤ
ѲäƤʤäϡ 0 ֤
顼ξ \-1 ֤

.BR waitid ():
 0 ֤
.B WNOHANG
ꤵƤơ
.I pid
ǻؼ줿ҥץǾѲäƤʤäˤ
0 ֤
顼ξ \-1 ֤

顼ξ硢ΥƥॳϤ
.I errno
Ŭڤͤꤹ롣
.SH 顼
.TP
.B ECHILD
.RB ( wait ()
ξ)
ƤӽФץˤϡwait ԤäƤʤҥץϤʤ
.TP
.B ECHILD
.RB ( waitpid ()

.BR waitid ()
ξ)
.I pid
.RB ( waitpid ())

.I idtype

.I id
.RB ( waitid ())
ǻꤷץ¸ߤʤƤӽФץλҥץǤʤ
.RB ( SIGCHLD
ư
.B SIG_IGN
ꤷˤϡʬȤλҥץǤⵯꤦ롣
åɤ˴ؤƤϡLinux Ǥաפ⻲Ȥ뤳)
.TP
.B EINTR
.B WNOHANG
ꤵƤ餺ػ (block) Ƥʤʥ
.B SIGCHLD

.TP
.B EINVAL
.I options
Ǥ롣
.SH 
SVr4, 4.3BSD, POSIX.1-2001.
.SH 
λwait Ƥʤҥץϡ֥ӡפˤʤ롣
ǿƥץ wait ¹ԤƻҥץˤĤƤξǤ褦ˡ
ͥϥӥץˤĤƺǾ¤ξ (PIDλơ
꥽Ѿ) ݻ롣
ӥץϡ wait ˤäƥƥफʤ¤ꡢ
ͥΥץơ֥ 1 ȥ񤹤롣Υץơ֥뤬
դˤʤȡ˥ץ뤳ȤǤʤʤ롣
ƥץλȡοƥץΡ֥ӡפ
ҥץ (⤷)
.BR init (8)
ܻҤȤʤ롣
.BR init (8)
 wait ưŪ˼¹ԤӤ롣

POSIX.1-2001 ǤϰʲΤ褦˵ꤵƤ롣
.B SIGCHLD
ư
.B SIG_IGN
ꤵ줿
.B SIGCHLD
Ф
.B SA_NOCLDWAIT
ե饰ꤵ줿
.RB ( sigaction (2)
)λҥץϥӤˤϤʤ餺
.BR wait ()

.BR waitpid ()
θƤӽФƤλҥץλޤߤ
ҥץλ
.I errno

.B ECHILD
ꤷƼԤ롣
(ȤȤ POSIX ɸ
.B SIGCHLD

.B SIG_IGN
ꤷο񤤤̤ΤޤޤˤƤ롣)
Linux 2.6 Ϥλͤ˽򤷤Ƥ롣
Linux 2.4 (ȤΥС) ϤǤϤʤ:
.B SIGCHLD
̵뤵֤
.BR wait ()
ޤ
.BR waitpid ()
ƤӽФ줿硢
.B SIGCHLD
̵뤵ƤʤΤ褦˿񤦡
ĤޤꡢƤӽФˤäƼλҥץνλޤǥ֥å졢
λҥץ PID Ⱦ֤֤롣
.SS Linux Ǥ
Linux ͥǤϡͥˤäƥ塼뤵륹åɤ
ץΤ˶̤Ǥ빽ǤǤϤʤåɤ Linux ͭ
.BR clone (2)
ƥॳѤץ˲᤮ʤ
ܿΤ
.BR pthread_create (3)
Τ褦¾Υ롼
.BR clone (2)
ѤƼƤ;
Ǥ
.BR waitid ()
ȤȤϤǤʤ
Linux 2.4 ǤϡåɤñüʥץǤäΤǡ
㤨Ʊåɥ롼פǤäƤ⡢
륹åɤ̤ΥåɤλҥץλΤԤĤȤϽʤä
POSIX ǤϤΤ褦ʵǽꤷƤꡢ
Linux 2.4 ʹߤǤϡ륹åɤƱåɥ롼פ¾Υåɤ
ҥץλΤԤĤȤǤ褦ˤʤä
ƾϤ줬ǥեȤưˤʤǤ
.LP
.BR clone (2)
Ѥƺ줿ҥץˤϡʲ Linux ͭ
.I options
ѤǤ롣
.TP
.B __WCLONE
.\" since 0.99pl10
"clone" ʻҥץԤġ
ꤵʤä "clone" ʻҥץԤ
("clone" ʻҥץϡλ˿ƥץʥʤ
.B SIGCHLD
ʳΥʥ)
Υץ
.B __WALL
ꤵ줿̵뤵롣
.TP
.B __WALL
.\" since patch-2.3.48
(Linux 2.4 ʹ) "clone" Ǥ뤫ʤ˴ؤ餺
ƤλҥץԤġ
.TP
.B __WNOTHREAD
.\" since patch-2.4.0-test8
(Linux 2.4 ʹ) Ʊåɥ롼פ¾ΥåɤλҥץԤʤ
Linux 2.4 ǤϥǥեȤǤä
.SH 
.\" fork.2 ⤳Υץץ򻲾ȤƤ롣
ʲΥץϡ
.BR fork (2)

.BR waitpid ()
λˡ򼨤Ƥ롣
ΥץǤϻҥץ롣
ޥɥ饤ꤵʤäȤϡ
ҥץ
.BR pause (2)
ȤäƤμ¹Ԥߤ桼λҥץ
ʥǤ褦ˤ롣
ޥɥ饤ꤵ줿ϡ
ҥץľ˽λ
ޥɥ饤ǻꤵ줿λơȤƻѤ롣
ƥץϡ
.BR waitpid ()
Ȥäƻҥץƻ뤷
wait Υơͤ嵭 W*() ޥȤäƲϤȤ
롼פ¹Ԥ롣

ΤΥ롦åϥץμ¹Ǥ:
.nf

$ ./a.out &
Child PID is 32360
[1] 32359
$ kill \-STOP 32360
stopped by signal 19
$ kill \-CONT 32360
continued
$ kill \-TERM 32360
killed by signal 15
[1]+  Done                    ./a.out
$

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

int
main(int argc, char *argv[])
{
    pid_t cpid, w;
    int status;

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

    if (cpid == 0) {            /* Code executed by child */
        printf("Child PID is %ld\\n", (long) getpid());
        if (argc == 1)
            pause();                    /* Wait for signals */
        _exit(atoi(argv[1]));

    } else {                    /* Code executed by parent */
        do {
            w = waitpid(cpid, &status, WUNTRACED | WCONTINUED);
            if (w == \-1) {
                perror("waitpid");
                exit(EXIT_FAILURE);
            }

            if (WIFEXITED(status)) {
                printf("exited, status=%d\\n", WEXITSTATUS(status));
            } else if (WIFSIGNALED(status)) {
                printf("killed by signal %d\\n", WTERMSIG(status));
            } else if (WIFSTOPPED(status)) {
                printf("stopped by signal %d\\n", WSTOPSIG(status));
            } else if (WIFCONTINUED(status)) {
                printf("continued\\n");
            }
        } while (!WIFEXITED(status) && !WIFSIGNALED(status));
        exit(EXIT_SUCCESS);
    }
}
.fi
.SH Ϣ
.BR _exit (2),
.BR clone (2),
.BR fork (2),
.BR kill (2),
.BR ptrace (2),
.BR sigaction (2),
.BR signal (2),
.BR wait4 (2),
.BR pthread_create (3),
.BR credentials (7),
.BR signal (7)