stdlib/system-fbsd.c

   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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)system.c    8.1 (Berkeley) 6/4/93";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/stdlib/system.c,v 1.10 2002/03/22 21:53:10 obrien Exp $");
  39
  40 #include "namespace.h"
  41 #include <sys/types.h>
  42 #include <sys/wait.h>
  43 #include <signal.h>
  44 #include <stdlib.h>
  45 #include <stddef.h>
  46 #include <unistd.h>
  47 #include <paths.h>
  48 #include <errno.h>
  49 #include "un-namespace.h"
  50 #include "libc_private.h"
  51
  52 #if __DARWIN_UNIX03
  53 #include <pthread.h>
  54
  55 static pthread_mutex_t __systemfn_mutex = PTHREAD_MUTEX_INITIALIZER;
  56 extern int __unix_conforming;
  57 #ifdef VARIANT_CANCELABLE
  58 extern void _pthread_testcancel(pthread_t thread, int isconforming);
  59 #endif /* VARIANT_CANCELABLE */
  60 #endif /* __DARWIN_UNIX03 */
  61
  62 int
  63 __system(command)
  64         const char *command;
  65 {
  66         pid_t pid, savedpid;
  67         int pstat;
  68         struct sigaction ign, intact, quitact;
  69         sigset_t newsigblock, oldsigblock;
  70
  71 #if __DARWIN_UNIX03
  72         if (__unix_conforming == 0)
  73                 __unix_conforming = 1;
  74 #ifdef VARIANT_CANCELABLE
  75         _pthread_testcancel(pthread_self(), 1);
  76 #endif /* VARIANT_CANCELABLE */
  77 #endif /* __DARWIN_UNIX03 */
  78
  79         if (!command) {         /* just checking... */
  80                 if (access(_PATH_BSHELL, F_OK) == -1)   /* if no sh or no access */
  81                         return(0);
  82                 else
  83                         return(1);
  84         }
  85
  86 #if __DARWIN_UNIX03
  87         pthread_mutex_lock(&__systemfn_mutex);
  88 #endif /* __DARWIN_UNIX03 */
  89         /*
  90          * Ignore SIGINT and SIGQUIT, block SIGCHLD. Remember to save
  91          * existing signal dispositions.
  92          */
  93         ign.sa_handler = SIG_IGN;
  94         (void)sigemptyset(&ign.sa_mask);
  95         ign.sa_flags = 0;
  96         (void)_sigaction(SIGINT, &ign, &intact);
  97         (void)_sigaction(SIGQUIT, &ign, &quitact);
  98         (void)sigemptyset(&newsigblock);
  99         (void)sigaddset(&newsigblock, SIGCHLD);
 100         (void)_sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
 101         switch(pid = fork()) {
 102         case -1:                        /* error */
 103                 break;
 104         case 0:                         /* child */
 105                 /*
 106                  * Restore original signal dispositions and exec the command.
 107                  */
 108                 (void)_sigaction(SIGINT, &intact, NULL);
 109                 (void)_sigaction(SIGQUIT,  &quitact, NULL);
 110                 (void)_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
 111 #if __DARWIN_UNIX03
 112                 pthread_mutex_unlock(&__systemfn_mutex);
 113 #endif /* __DARWIN_UNIX03 */
 114                 execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL);
 115                 _exit(127);
 116         default:                        /* parent */
 117                 savedpid = pid;
 118                 do {
 119                         pid = _wait4(savedpid, &pstat, 0, (struct rusage *)0);
 120                 } while (pid == -1 && errno == EINTR);
 121                 break;
 122         }
 123         (void)_sigaction(SIGINT, &intact, NULL);
 124         (void)_sigaction(SIGQUIT,  &quitact, NULL);
 125         (void)_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
 126 #if __DARWIN_UNIX03
 127         pthread_mutex_unlock(&__systemfn_mutex);
 128 #endif /* __DARWIN_UNIX03 */
 129         return(pid == -1 ? -1 : pstat);
 130 }
 131
 132 __weak_reference(__system, system);
 133 __weak_reference(__system, _system);