.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
.\"
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.\" manual provided the copyright notice and this permission notice are
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.\" manual page may be incorrect or out-of-date.  The author(s) assume no
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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.
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.\" Modified by Michael Haardt <michael@moria.de>
.\" Modified 1993-07-21 by Rik Faith <faith@cs.unc.edu>
.\" Modified 1994-08-21 by Michael Chastain <mec@shell.portal.com>:
.\" Modified 1997-01-31 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified 1999-11-12 by Urs Thuermann <urs@isnogud.escape.de>
.\" Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
.\"
.\" Japanese Version Copyright (c) 1996 TABATA Tomohira
.\"         all rights reserved.
.\" Translated 1996-07-04, TABATA Tomohira <loba@k2.t.u-tokyo.ac.jp>
.\" Modified 1997-12-14, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Modified 2001-08-17, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Modified 2005-02-05, Yuichi SATO <ysato444@yahoo.co.jp>
.\" Modified 2005-09-06, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" Modified 2005-11-19, Akihiro MOTOKI
.\" Modified 2006-08-13, Akihiro MOTOKI, LDP v2.39
.\"
.TH EXECVE 2 2004-06-23 "Linux 2.6.7" "Linux Programmer's Manual"
.SH ̾
execve \- ץ¹Ԥ
.SH 
.B #include <unistd.h>
.sp
.BI "int execve(const char *" filename ", char *const " argv "[], "
.br
.BI "           char *const " envp []);
.SH 
\fBexecve\fP() ϡ\fIfilename\fP ˤäƻꤵ줿ץ¹Ԥ롣
\fIfilename\fP ϡХʥ¹Է"\fB#! \fIinterpreter \fR[arg]" 
ȤιԤǻϤޤ륹ץȤǤʤФʤʤ
Ԥξ硢interpreter Ŭڤʼ¹ԥեΥѥ̾ǤʤФʤ餺
켫ȤץȤǤäƤϤʤʤƤ
\fBinterpreter\fR [arg] \fIfilename\fR ηǸƤӽФ롣

\fIargv\fP ϿץϤʸǤ롣
\fIenvp\fP ʸǤꡢŪ \fBkey=value\fR η
ƤꡢץδĶѿȤϤ롣
\fIargv\fP  \fIenvp\fP ξȤ NULL ݥ󥿤ǽäƤ
ɬפ롣ȴĶѿϸƤӽФ줿ץ main ؿ
\fBint main(int argc, char *argv[], char *envp[])\fR
Τ褦뤳Ȥˤäƥǽˤʤ롣

硢\fBexecve\fP() ֤ʤ
ơƤӽФΥץ text, data, bss, åϡ
ɤ߹ޤ줿ץˤäƾ񤭤롣
ƤӽФ줿ץϡƤӽФ PID  
exec  (close-on-exec) ꤵƤʤ٤Ƥ
ե롦ǥץѾ롣
ƤӽФץαʥϲ롣ƤӽФΥץ
ꤵ줿ʥͻưϥǥեưᤵ롣
SIGCHLD ʥ뤬 SIG_IGN ꤵƤ SIG_DFL ˥ꥻå
뤫⤷ʤʤ⤷ʤ

⤷Υץब ptrace Ƥȡ\fBexecve\fP() 
Υץ \fBSIGTRAP\fP 롣

\fIfilename\fP ǻꤵ줿ץե set-user-ID ӥåȤ
ꤵƤꡢƤӽФץ ptrace Ƥʤ硢
ƤӽФץμ¸ (effective) 桼 ID 
ץեνͭ (owner) ѹ롣
Ʊͤˡץե set-group-ID ӥåȤꤵƤ硢
ƤӽФץͭ롼 ID 
ץեΥ롼פѹ롣

ץμ¸桼 ID ¸ (saved) set-user-ID ˥ԡ롣
Ʊͤˡ¸롼 ID ¸ set-group-ID ˥ԡ롣
Υԡϡset-user-ID / set-group-ID ĥӥåȤˤȯ
¸ ID ѹ˹Ԥ롣

¹ԥե뤬ưŪ󥯤줿 a.out ¹Էǡͭ饤֥
֤ޤΤä硢¹Ԥγϻ Linux 
ʥߥå
.BR ld.so (8)
ƤӽФ졢ɬפʶͭ饤֥ɤ߹ǥ󥯤Ԥ

¹ԥե뤬ʥߥå󥯤줿 ELF ¹Էä硢
PT_INTERP Ȥ˻ꤵ줿󥿥ץ꥿ɬפ
ͭ饤֥ (shared library) ɤ߹Τ˻Ѥ롣
̾Ѥ륤󥿥ץ꥿ Linux libc version 5 󥯤Хʥ
ξˤ \fI/lib/ld-linux.so.1\fR GNU libc version 2 󥯤
Хʥξˤ \fI/lib/ld-linux.so.2\fR Ѥ롣
.SH ֤
 \fBexecve\fP() ֤ʤ顼ξ \-1 ֤
.I errno
Ŭꤹ롣
.SH 顼
.TP
.B E2BIG
Ķѿ
.RI ( envp )
Ȱꥹ
.RI ( argv )
ιץХȿ礭᤮롣
.TP
.B EACCES
.I filename
䥹ץȥ󥿥ץ꥿̾ιǤ˸ (search permission)
ͿƤʤ
.RB ( path_resolution (2)
⻲Ȥ뤳)
.TP
.B EACCES
ե⤷ϥץȤΥ󥿥ץ꥿̾ե (regular file)
Ǥʤ
.TP
.B EACCES
ե䥹ץȤ ELF 󥿥ץ꥿
¹Ե (execute permission) ͿƤʤ
.TP
.B EACCES
ե롦ƥब
.I noexec 
ǥޥȤƤ롣
.TP
.B EFAULT
.I filename
ǽʥɥ쥹֤γؤƤ롣
.TP
.B EINVAL
ELF ¹Էʣ PT_INTERP Ȥ¸ߤ롣
(ʤʣΥ󥿥ץ꥿ꤷ)
.TP
.B EIO
I/O 顼ȯ
.TP
.B EISDIR
ELF 󥿥ץ꥿ǥ쥯ȥä
.TP
.B ELIBBAD
ELF 󥿥ץ꥿ǤեޥåȤǤʤä
.TP
.B ELOOP
.I filename
䥹ץȤ ELF Υ󥿥ץ꥿褹ݤ
ܥå󥯤¿᤮롣
.TP
.B EMFILE
ΥץץǤեξ¤ޤǴ˥ץ󤷤Ƥ롣
.TP
.B ENAMETOOLONG
.I filename
Ĺ᤮롣
.TP
.B ENFILE
ΥƥǥץǤե¤ã
.TP
.B ENOENT
ե
.I filename
ץȤ ELF Υ󥿥ץ꥿¸ߤʤ
.TP
.B ENOEXEC
¹ԥե뤬ǤʤǤ뤫㤦ƥΤΤ
¾Υեޥåȡ顼ˤ¹ԤǤʤä
.TP
.B ENOMEM
ͥ˽ʬʥ꤬ʤ
.TP
.B ENOTDIR
.I filename
䥹ץȤ ELF Υ󥿥ץ꥿ιǤǥ쥯ȥǤʤ
.TP
.B EPERM
ե롦ƥब
.I nosuid
ǥޥȤ졢桼ѡ桼Ǥʤ
ե SUID 뤤 SGID ӥåȤꤵƤ롣
.TP
.B EPERM
ץȥ졼졢桼ѡ桼Ǥʤ
ե SUID 뤤 SGID ӥåȤꤵƤ롣
.TP
.B ETXTBSY
¹ԥե񤭹Ѥ˥ץ󤷤Ƥץ롣
.SH 
SVr4, 4.3BSD, POSIX.1-2001.  
POSIX.1-2001 ˤ #! ưˤĤƤεҤϤʤ
¾ϸߴ롣
.\" SVr4 ˤ¾ EAGAIN, EINTR, ELIBACC, ENOLINK, EMULTIHOP
.\" ˤĤƤεҤ롣
.\" POSIX ˤ ETXTBSY, EPERM, EFAULT, ELOOP, EIO, ENFILE, EMFILE, 
.\" EINVAL, EISDIR, ELIBBAD 顼֤ˤĤƤεҤϤʤ
.SH 
SUID ץ SGID ץ \fBptrace\fP() Ǥʤ

Linux ϥץȤ SUID  SGID ӥåȤ̵뤹롣

ե륷ƥ
.I nosuid
ǥޥȤ SUID/SGID ¹ԥեɤͤ˰ϡ
Linux ͥΥСˤäưۤʤ:
СǤϡǤɬפʸ¤äƤơ
μ¹Ԥݤ ( EPERM ֤)̤ΤСǤ
SUID/SGID ӥåȤΤߤ̵뤷
.BR exec ()
롣

#! ¹ԷΥ롦ץȤΣܤˤϺ 127 ʸƤ롣
.\" .SH Х
.\" Linux ǤˤϡELF 󥿥ץ꥿ˤ
.\" ¤Υå˼ԤΤ롣
.\" ϥƥۡǤ롣
.\" ʤʤ顢桼ǤդΥե򥪡ץĤꡢ
.\" ɤ߹ߤΤ˥ơץǥХ򴬤ᤷĤꤹ롣
.\" Linux Ǥˤ \fBexecve\fP() ¾Υƥۡ뤬
.\" ¸ߤΤ⤢ꡢ̯˺ٹ줿 ELF Хʥˤä
.\" ӥ (denial of service) ѤƤޤ
.\" 2.0.34 ޤ 2.2.15 ˤϡΤƤϤʤ
.SH 
Unix V6 Ǥ
.BR exec ()
ΰꥹȤ 0 ǽü졢
.I main
ΰꥹȤ \-1 ǽüƤ
Τᡢ
.I main
ΰꥹȤϡθ
.BR exec ()
ˤľܻѤǤʤä
Unix V7 ʹߤǤϡȤ NULL ǽü롣
.SH Ϣ
.BR chmod (2),
.BR fork (2),
.BR path_resolution (2),
.BR ptrace (2),
.BR execl (3),
.BR fexecve (3),
.BR environ (7),
.BR ld.so (8).