1 /*
2 * Copyright (c) 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)system.c 8.1 (Berkeley) 6/4/93
30 * $FreeBSD: src/lib/libc/stdlib/system.c,v 1.11 2007/01/09 00:28:10 imp Exp $
31 */
32
33 #include "namespace.h"
34 #include <sys/types.h>
35 #include <sys/wait.h>
36 #include <signal.h>
37 #include <stdlib.h>
38 #include <stddef.h>
39 #include <unistd.h>
40 #include <paths.h>
41 #include <errno.h>
42 #include "un-namespace.h"
43 #include "libc_private.h"
44
45 int __system(const char *);
46
47 int
__system(const char * command)48 __system(const char *command)
49 {
50 pid_t pid, savedpid;
51 int pstat;
52 struct sigaction ign, intact, quitact;
53 sigset_t newsigblock, oldsigblock;
54
55 if (!command) /* just checking... */
56 return(1);
57
58 /*
59 * Ignore SIGINT and SIGQUIT, block SIGCHLD. Remember to save
60 * existing signal dispositions.
61 */
62 ign.sa_handler = SIG_IGN;
63 sigemptyset(&ign.sa_mask);
64 ign.sa_flags = 0;
65 _sigaction(SIGINT, &ign, &intact);
66 _sigaction(SIGQUIT, &ign, &quitact);
67 sigemptyset(&newsigblock);
68 sigaddset(&newsigblock, SIGCHLD);
69 _sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
70 switch(pid = fork()) {
71 case -1: /* error */
72 break;
73 case 0: /* child */
74 /*
75 * Restore original signal dispositions and exec the command.
76 */
77 _sigaction(SIGINT, &intact, NULL);
78 _sigaction(SIGQUIT, &quitact, NULL);
79 _sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
80 execl(_PATH_BSHELL, "sh", "-c", command, NULL);
81 _exit(127);
82 default: /* parent */
83 savedpid = pid;
84 do {
85 pid = _wait4(savedpid, &pstat, 0, NULL);
86 } while (pid == -1 && errno == EINTR);
87 break;
88 }
89 _sigaction(SIGINT, &intact, NULL);
90 _sigaction(SIGQUIT, &quitact, NULL);
91 _sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
92 return(pid == -1 ? -1 : pstat);
93 }
94
95 __weak_reference(__system, system);
96 __weak_reference(__system, _system);
97