stdlib/FreeBSD/system.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  * 4. 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
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)system.c    8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/stdlib/system.c,v 1.11 2007/01/09 00:28:10 imp Exp $");
  35
  36 #include "namespace.h"
  37 #include <sys/types.h>
  38 #include <sys/wait.h>
  39 #include <signal.h>
  40 #include <stdlib.h>
  41 #include <stddef.h>
  42 #include <unistd.h>
  43 #include <paths.h>
  44 #include <errno.h>
  45 #include "un-namespace.h"
  46 #include "libc_private.h"
  47
  48 int
  49 __system(command)
  50         const char *command;
  51 {
  52         pid_t pid, savedpid;
  53         int pstat;
  54         struct sigaction ign, intact, quitact;
  55         sigset_t newsigblock, oldsigblock;
  56
  57         if (!command)           /* just checking... */
  58                 return(1);
  59
  60         /*
  61          * Ignore SIGINT and SIGQUIT, block SIGCHLD. Remember to save
  62          * existing signal dispositions.
  63          */
  64         ign.sa_handler = SIG_IGN;
  65         (void)sigemptyset(&ign.sa_mask);
  66         ign.sa_flags = 0;
  67         (void)_sigaction(SIGINT, &ign, &intact);
  68         (void)_sigaction(SIGQUIT, &ign, &quitact);
  69         (void)sigemptyset(&newsigblock);
  70         (void)sigaddset(&newsigblock, SIGCHLD);
  71         (void)_sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
  72         switch(pid = fork()) {
  73         case -1:                        /* error */
  74                 break;
  75         case 0:                         /* child */
  76                 /*
  77                  * Restore original signal dispositions and exec the command.
  78                  */
  79                 (void)_sigaction(SIGINT, &intact, NULL);
  80                 (void)_sigaction(SIGQUIT,  &quitact, NULL);
  81                 (void)_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
  82                 execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL);
  83                 _exit(127);
  84         default:                        /* parent */
  85                 savedpid = pid;
  86                 do {
  87                         pid = _wait4(savedpid, &pstat, 0, (struct rusage *)0);
  88                 } while (pid == -1 && errno == EINTR);
  89                 break;
  90         }
  91         (void)_sigaction(SIGINT, &intact, NULL);
  92         (void)_sigaction(SIGQUIT,  &quitact, NULL);
  93         (void)_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
  94         return(pid == -1 ? -1 : pstat);
  95 }
  96
  97 __weak_reference(__system, system);
  98 __weak_reference(__system, _system);