.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" Copyright (c) 1992 Drew Eckhardt <drew@cs.colorado.edu>, March 28, 1992
.\" May be distributed under the GNU General Public License.
.\" Modified by Michael Haardt <michael@moria.de>
.\" Modified Sat Jul 24 13:22:07 1993 by Rik Faith <faith@cs.unc.edu>
.\" Modified 21 Aug 1994 by Michael Chastain <mec@shell.portal.com>:
.\"   New man page (copied from 'fork.2').
.\" Modified 10 June 1995 by Andries Brouwer <aeb@cwi.nl>
.\" Modified 25 april 1998 by Xavier Leroy <Xavier.Leroy@inria.fr>
.\" Modified 26 Jun 2001 by Michael Kerrisk
.\"     Mostly upgraded to 2.4.x
.\"     Added prototype for sys_clone() plus description
.\"     Added CLONE_THREAD with a briefdescription of thread groups
.\"     Added CLONE_PARENT and revised entire page remove ambiguity 
.\"             between "calling process" and "parent process"
.\"     Added CLONE_PTRACE and CLONE_VFORK
.\"     Added EPERM and EINVAL error codes
.\"     Renamed "__clone" to "clone" (which is the protype in <sched.h>)
.\"     various other minor tidy ups and clarifications.
.\"
.\" Japanese Version Copyright (c) 2001 HANATAKA Shinya
.\"         all rights reserved.
.\" Translated Fri Aug 17 20:32:10 JST 2001
.\"         by HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\"
.TH CLONE 2 2001-06-26 "Linux 2.4" "Linux Programmer's Manual"
.SH ̾
clone \- ҥץ
.SH 
.B #include <sched.h>
.sp
.BI "int clone(int (*" "fn" ")(void *), void *" "child_stack" ", int " "flags" ", void *" "arg" );
.sp
.BI "_syscall2(int, " "clone" ", int, " "flags" ", void *, " "child_stack" );

.SH 
.B clone 

.BR fork (2)
Ʊ褦˿ץ롣
.B clone
ˤϥ饤֥ؿȤβؤȤʤ
.B clone
ƥॳ뤬¸ߤ롢ʲǤϥƥॳˤĤƤ
.B sys_clone 
ȤƵҤƤƤ롣
.B sys_clone
˴ؤϤΥڡκǸˤ롣

.BR fork (2)
ȰäƤΥϻҥץ(child process)֡
ե롦ǥץΥơ֥롢ʥ롦ϥɥ顼Υơ֥ʤɤ
¹ԥƥȤΰƤӽФץȶͭ뤳Ȥǽˤ롣
(Υޥ˥奢ˤָƤӽФץפȤ̾
ֿƥץפ̣Ƥ뤳Ȥդ뤳ȡʲ
.B CLONE_PARENT 
εҤ⻲)

.B clone
μפʻˡϥå(threads)뤳ȤǤ:
ĤΥץʣΥåɤ϶ͭ줿֤
ƶĴƼ¹Ԥ롣
 
ҥץ
.B clone 
Ǻ줿ˡؿ
.IR fn ( arg )
¹Ԥ롣
(
.BR fork (2)
ȤϰۤʤäƤ롣
.BR fork (2) 
ϸƤӽФ줿꤫ҥץμ¹Ԥ³롣)
.I fn
ϻҥץ¹ԤϤ˸ƤӽФؿؤΥݥ󥿡Ǥ롣
.I arg
ϤΤޤ
.I fn
ؿؤϤ롣

.IR fn ( arg )
ؿ֤ȡҥץϽλ롣
.I fn
ˤä֤줿ϻҥץνλɤȤʤ롣
ҥץŪ
.BR exit (2)
Ƥꡢ̿Ūʥʥˤ⽪λ롣

.I child_stack
ϻҥץˤäƻѤ륹åΰ֤ꤹ롣
ҥץȸƤӽФץϥͭ뤿ᡢ̤˻ҥץ
ƤӽФץƱåǼ¹Ԥ뤳ȤǤʤ
ΤƤӽФץϻҥץΥåΤΥ֤
ơζ֤ؤΥݥ󥿡
.B clone 
ϤʤФʤʤ
Linux äƤ(HP PA ץå)ƤΥץåǤϡ
åϲؤĹ롣Τ
.I child_stack
񡢻ҥץΥåΤꤷ֤ΰ礭
ɥ쥹ؤƤ롣

.I flags
β̥ХȤϻҥץ˿ƥץؤ
ʥֹꤹ롣ʥȤ
.B SIGCHLD
ʳꤵ줿硢ƥץϻҥץԤĺݤ
.BR wait (2) 

.B __WALL 
ޤ
.B __WCLONE
ꤷʤФʤʤ
ɤΥʥꤵʤä硢ҥץλ˿ƥץ
˥ʥʤ

.I flags
ˤϤ˰ʲӥå OR(bitwise-or)Ƥɤ
ϿƥץȻҥץδ֤Dzͭ뤫ꤹ:

.TP
.B CLONE_PARENT
(Linux 2.4 ʹߤ)
.B CLONE_PARENT
ꤵ줿硢Ҷ(
.BR getppid (2)
֤)ƥץϸƤӽФץοƥץƱˤʤ롣

.B CLONE_PARENT
ꤵƤʤ硢
.RB ( fork (2)
Ʊͤ)ƤӽФץλҶοƤˤʤ롣

Ҷλ˥ʥ뤬Τ
.BR getppid (2)
֤ƥץǤ뤳Ȥդ뤳ȡΤ
.B CLONE_PARENT
ꤵ줿硢ƤӽФץǤϤʤƤӽФץ
ƥץ˥ʥ뤬롣

.TP
.B CLONE_FS
.B CLONE_FS
ꤵ줿硢ƤӽФץȻҥץƱե롦ƥ
ͭ롣ˤϥե륷ƥΥ롼(root)丽ߤ
󥰡ǥ쥯ȥ(current working directory) umask ޤޤ롣
ƤӽФץҥץˤäƹԤʤ줿Ƥ
.BR chroot (2),
.BR chdir (2),
.BR umask (2)
¾Υץˤƶ롣

.B CLONE_FS
ꤵƤʤ硢ҥץ
.BR clone 
¹Ԥ줿ǤθƤӽФץΥե롦ƥΥԡ
Ѥ롣
ʸ塢ץˤäƹԤʤ줿
.BR chroot (2),
.BR chdir (2),
.BR umask (2)
¾Υץˤϱƶʤ

.TP
.B CLONE_FILES
.B CLONE_FILES
ꤵ줿硢ƤӽФץȻҥץϥե롦ǥץ
ơ֥ͭ롣ե롦ǥץϻҥץȿƥץ
ˤƾƱե򻲾Ȥ롣ƤӽФץҥץˤä
줿ƤΥե롦ǥץ¾ΥץˤƤ
ͭǤ롣Ʊͤˡץե롦ǥץ
(close)䡢Ϣե饰ѹԤʤä¾Υץ
ƶ롣

.B CLONE_FILES
ꤵƤʤ硢ҥץ
.BR clone 
¹Ԥ줿ǤθƤӽФץץ(open)ƤƤ
ե롦ǥץΥԡѾ롣
ʸ塢ץˤäƹԤʤ줿ե롦ǥץ
Ф¾Υץˤϱƶʤ

.TP
.B CLONE_SIGHAND
.B CLONE_SIGHAND
ꤵ줿硢ƤӽФץȻҥץƱʥ롦ϥɥ顼
ơ֥ͭ롣ƤӽФץޤϻҥץ
.BR sigaction (2)
ˤäƥʥ˴ϢŤ줿ưѹ硢Ʊͤ
¾Υץưѹ롣ǡƤӽФץȻҥץ
̤Υʥ롦ޥ(signal mask)ȲԤΥʥνäƤ롣
äơץ¾Υץ˱ƶͿ뤳Ȥʤ
.BR sigprocmask (2)
Ѥƥʥػ(block)(unblock)Ǥ롣

.B CLONE_SIGHAND
ꤵƤʤ硢ҥץ
.B clone
¹Ԥ줿ǤθƤӽФץΥʥ롦ϥɥ顼
ԡѾ롣ʸ塢ץˤäƹԤʤ줿
.BR sigaction (2)
¾Υץˤϱƶʤ

.TP
.B CLONE_PTRACE
.B CLONE_PTRACE
ꤵ졢ƤӽФץȥ졼Ƥ硢ҥץ
Ʊͤפ롣
.RB ( ptrace (2)
򻲾Ȥ뤳)

.TP
.B CLONE_VFORK
.B CLONE_VFORK
ꤵ줿硢
.RB ( vfork (2)
Ʊͤ)ҥץ
.BR execve (2)
ޤ
.BR _exit (2)
ˤäƲۥޤǸƤӽФץϼ¹Ԥߤ롣

.B CLONE_VFORK
ꤵƤʤ硢ƤӽФϸƤӽФץȻҥץ
ξ塼뤵롣ץꥱϤ餬ɤΤ褦ʽ֤
¹Ԥ뤫ˤĤΤ뤳ȤϤǤʤ

.TP
.B CLONE_VM
.B CLONE_VM
ꤵ줿硢ƤӽФץȻҥץƱ֤
¹Ԥ롣ä˸ƤӽФץҥץˤäƥ
񤭹ޤ줿Ƥ¾ΥץˤäƤ⸫뤳ȤǤ롣ˡ
ҥץƤӽФץ
.BR mmap (2)

.BR munmap (2)
Ȥäƥޥåפꥢޥåפ硢
¾Υץˤƶ롣

.B CLONE_VM
ꤵƤʤ硢ҥץ
.BR clone 
¹Ԥ줿ǤοƥץΥ֤򥳥ԡ
̤Υ֤Ǽ¹Ԥ롣
ץǹԤʤ줿ؤν񤭹ߤ
եΥޥå/ޥåפ
.BR fork (2)
ξƱ͡¾Υץˤϱƶʤ

.TP
.B CLONE_PID
.B CLONE_PID
ꤵ줿硢ҥץϸƤӽФץƱץ ID 
롣

.B CLONE_PID
ꤵƤʤ硢ҥץϸͭΥץ ID 
ƤӽФץȤ϶̤롣

Υե饰ϥƥࡦ֡ȡץ(PID 0)Τ߻Ǥ롣

.TP
.B CLONE_THREAD
(Linux 2.4 ʹߤ)
.B CLONE_THREAD
ꤵ줿硢ҥץϸƤӽФץƱåɡ롼פ
֤롣

.B CLONE_THREAD
ꤵƤʤ硢ҥץȼ()åɡ롼פ
֤졢åɡ롼 ID ϤΥץ ID Ʊˤʤ롣

åɡ롼פ POSIX åɤΥåɽǰĤ PID ͭ
Ȥǰ򥵥ݡȤ뤿 Linux 2.4 ˲ä줿Linux 2.4 Ǥ
.BR getpid (2)
ϤΥץΥåɡ롼 ID ֤
.PP
.B sys_clone
ƥࡦϤ
.BR fork (2)
˶ᤤˤʤäƤꡢҥץϸƤӽФ줿꤫¹Ԥ³롣
Τ
.B sys_clone

.I flags

.I child_stack
ΤߤɬפȤ
.B clone
Ʊ̣ġ
(ΰν֤
.BR clone
ȤϰۤʤäƤ뤳Ȥդ뤳)

.B sys_clone
Τ⤦Ĥΰ㤤
.I child_stack
ǤɤȤǤ롣ξˤϤɤ餫Υץå
ѹˤϡ񤭹߻ԡ(copy-on-write)ǻҥץ
åڡΩԡ뤳Ȥݾڤ롣ξˤϡ
ư뤿ˡ
.B CLONE_VM
ץꤷƤϤʤʤ

.SH ֤
硢ƤӽФ¹ԥåɤˤϻҥץ PID ֤롣
Ԥ硢 ƤӽФƥȤˤ \-1 ֤졢ҥץ
줺

.I errno
Ŭڤꤵ롣

.SH 顼
.TP
.B EAGAIN
ǤäƤץ¿᤮롣
.TP
.B ENOMEM
ҥץΤ˳ݤ٤¤Τ䡢ƤӽФƥȤ
򥳥ԡΤɬפʥʬ˳Ƥ뤳ȤǤʤ
.TP
.B EINVAL
.IR child_stack 
˥ꤷ
.B clone 
֤
.TP 
.B EPERM
PID ʳΥץ
.B CLONE_PID
ꤷ

.SH Х

ͥ롦С 2.1.97 λǤ
.B CLONE_PID
ե饰ѤƤϤʤʤͥ¾ʬ¿
ƥࡦեȥץ ID ˤϽʣʤȤ
ꤷƤ뤿Ǥ롣

libc version 5 ˤ
.B clone
ΤΥȥ꤬¸ߤʤlibc 6 (ޤ̾ glibc2)
Υޥ˥奢롦ڡ˵ҤƤ
.B clone
󶡤롣

.SH 
.B clone

.B sys_clone
 Linux ͭǤꡢܿɬפʥץǤϻѤƤ
ʤʤåɤѤץꥱΥץߥˤ
(glibc2 ˴ޤޤƤ) LinuxThreads 饤֥Τ褦ʡ
POSIX 1003.1c thread API 饤֥Ѥɤ
.BR pthread_create (3)
򻲾Ȥ뤳ȡ

Υޥ˥奢롦ڡϥͥ 2.0.x, 2.1.x, 2.2.x, 2.4.x 
glibc 2.0.x, glibc 2.1.x бƤ롣

.SH Ϣ
.BR fork (2),
.BR wait (2),
.BR pthread_create (3)