1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
.\" (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de)
.\"
.\" 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.\" manual page may be incorrect or out-of-date.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 17:51:15 1993 by Rik Faith (faith@cs.unc.edu)
.\" Modified 11 May 1998 by Joseph S. Myers (jsm28@cam.ac.uk)
.\" Modified 14 May 2001, 23 Sep 2001 by aeb
.\"
.\" Japanese Version Copyright (c) 1996 Shoichi OZAWA
.\" all right reserved.
.\" Translated Sep 1 20:15:01 JST 1996
.\" by Shoichi OZAWA <ozawa@omika.hitachi.co.jp>
.\" Updated Sat Mar 19 JST 2001 by Kentaro Shirakata <argrath@ub32.org>
.\" Updated Tue Oct 16 JST 2001 by Kentaro Shirakata <argrath@ub32.org>
.\"
.TH SYSTEM 3 2001-09-23 "" "Linux Programmer's Manual"
.SH ̾
system \- 륳ޥɤμ¹
.SH
.nf
.B #include <stdlib.h>
.sp
.BI "int system(const char *" "string" );
.fi
.SH
.B system()
.I string
ǻꤷޥɤ
.BR "/bin/sh -c"
.IR string
ηǼ¹Ԥ롣ꤷޥɤλФδؿ⽪λ롣
ޥɼ¹
.B SIGCHLD
ϥ֥å졢
.B SIGINT
.B SIGQUIT
̵뤵롣
.SH ֤
顼ξ (fork ˼Ԥʤ) \-1 ֤
ʤСޥɤΥơ֤
Ԥξ硢ơ
.BR wait (2)
ƤեޥåȤ֤äƤ롣
äơޥɤνλɤ
.I WEXITSTATUS(status)
뤳Ȥ롣
.B /bin/sh
¹Խʤä硢
λơϥޥɤ
.I exit(127)
¹ԤΤ褦ʷȤʤ롣
.PP
.I string
ͤ
.BR NULL
ΤȤϡ
.B system()
ϥ뤬Ѳǽʤ饼ʳ֤ͤԲĤʤ饼֤
.PP
.B system()
¾λҥץΥȥơˤϱƶͿʤ
.SH
ANSI C, POSIX.2, BSD 4.3
.SH
.PP
˽Ҥ٤褦ˡ
.B system()
SIGINT SIGQUIT ̵뤹롣
ˤꡢ롼פ
.B system()
Ƥ֥ץϡ
ҥץνλ֤ʬǥåƤʤǤǤʤʤ롣
ʲǤ롣
.br
.nf
while(something) {
int ret = system("foo");
if (WIFSIGNALED(ret) &&
(WTERMSIG(ret) == SIGINT || WTERMSIG(ret) == SIGQUIT))
break;
}
.fi
.PP
suid sgid øĥץǤ
.B system()
ȤäƤϤʤʤʤ顢Ķѿ̤Τͤˤä
ƥΰ»ʤ뤫Ǥ롣
.BR exec (3)
Ϣδؿ
.BR execlp (3)
.BR execvp (3)
ʳδؿѤ٤Ǥ롣
ºݤΤȤ
.B system()
.B /bin/sh
bash С 2 Ǥ륷ƥǤϡ
suid sgid øĥץफưʤ
ʤʤ顢bash С 2 ϥȥåøȤǤ롣
(Debian Ǥϡsh ȤƵư줿ˤϤΤ褦ưԤʤʤ褦
줿 bash ѤƤ)
.PP
.B /bin/sh
ѲǽɤΥåϼºݤˤϹԤʤ鷺
ĤǤѲǽǤȲꤷƤ롣
ISO C ϥå褦ᤷƤ뤬
POSIX.2 Ͼ˥ʳ֤ȤƤ롣
ϥ뤬¸ߤʤƥ POSIX ǤϤʤǤ롣
(Linux glibc2 )(˥ʳ֤)褦˼Ƥ롣
.PP
¹Ԥ륳ޥɤ 127 (
.B /bin/sh
θƤӽФ˼Ԥ֤)֤Ȥͤ롣
Τᡢץ(ɤǤ)
.B execve()
θƤӽФԤȤμ¤Τ뤳ȤϤǤʤ
.SH Ϣ
.BR sh (1),
.BR signal (2),
.BR wait (2),
.BR exec (3)
|
