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[/] [openrisc/] [trunk/] [gnu-src/] [newlib-1.18.0/] [newlib/] [libc/] [sys/] [linux/] [system.c] - Blame information for rev 258

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Line No. Rev Author Line
1 207 jeremybenn
/* Copyright (C) 1991-1999, 2000 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library; if not, write to the Free
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   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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   02111-1307 USA.  */
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#include <stddef.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/wait.h>
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#include <signal.h>
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#include <sys/types.h>
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#include <errno.h>
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#include <machine/weakalias.h>
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#ifndef HAVE_GNU_LD
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#define __environ       environ
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#endif
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#define SHELL_PATH      "/bin/sh"       /* Path of the shell.  */
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#define SHELL_NAME      "sh"            /* Name to give it.  */
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/* Execute LINE as a shell command, returning its status.  */
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int
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__libc_system (const char *line)
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{
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  int status, save;
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  pid_t pid;
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  struct sigaction sa, intr, quit;
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#ifndef WAITPID_CANNOT_BLOCK_SIGCHLD
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  sigset_t block, omask;
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#endif
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  if (line == NULL)
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    /* Check that we have a command processor available.  It might
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       not be available after a chroot(), for example.  */
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    return __libc_system ("exit 0") == 0;
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  sa.sa_handler = SIG_IGN;
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  sa.sa_flags = 0;
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  sigemptyset (&sa.sa_mask);
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  if (sigaction (SIGINT, &sa, &intr) < 0)
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    return -1;
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  if (sigaction (SIGQUIT, &sa, &quit) < 0)
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    {
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      save = errno;
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      (void) sigaction (SIGINT, &intr, (struct sigaction *) NULL);
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      errno = save;
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      return -1;
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    }
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#ifndef WAITPID_CANNOT_BLOCK_SIGCHLD
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/* SCO 3.2v4 has a bug where `waitpid' will never return if SIGCHLD is
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   blocked.  This makes it impossible for `system' to be implemented in
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   compliance with POSIX.2-1992.  They have acknowledged that this is a bug
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   but I have not seen nor heard of any forthcoming fix.  */
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  sigemptyset (&block);
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  sigaddset (&block, SIGCHLD);
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  save = errno;
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  if (sigprocmask (SIG_BLOCK, &block, &omask) < 0)
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    {
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      if (errno == ENOSYS)
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        errno = save;
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      else
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        {
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          save = errno;
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          (void) sigaction (SIGINT, &intr, (struct sigaction *) NULL);
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          (void) sigaction (SIGQUIT, &quit, (struct sigaction *) NULL);
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          errno = save;
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          return -1;
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        }
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    }
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# define UNBLOCK sigprocmask (SIG_SETMASK, &omask, (sigset_t *) NULL)
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#else
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# define UNBLOCK 0
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#endif
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  pid = fork ();
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  if (pid == (pid_t) 0)
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    {
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      /* Child side.  */
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      const char *new_argv[4];
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      new_argv[0] = SHELL_NAME;
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      new_argv[1] = "-c";
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      new_argv[2] = line;
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      new_argv[3] = NULL;
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      /* Restore the signals.  */
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      (void) sigaction (SIGINT, &intr, (struct sigaction *) NULL);
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      (void) sigaction (SIGQUIT, &quit, (struct sigaction *) NULL);
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      (void) UNBLOCK;
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      /* Exec the shell.  */
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      (void) execve (SHELL_PATH, (char *const *) new_argv, __environ);
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      _exit (127);
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    }
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  else if (pid < (pid_t) 0)
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    /* The fork failed.  */
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    status = -1;
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  else
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    /* Parent side.  */
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    {
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#ifdef  NO_WAITPID
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      pid_t child;
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      do
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        {
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          child = wait (&status);
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          if (child <= -1 && errno != EINTR)
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            {
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              status = -1;
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              break;
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            }
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          /* Note that pid cannot be <= -1 and therefore the loop continues
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             when wait returned with EINTR.  */
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        }
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      while (child != pid);
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#else
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      int n;
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      do
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        n = waitpid (pid, &status, 0);
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      while (n == -1 && errno == EINTR);
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      if (n != pid)
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        status = -1;
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#endif
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    }
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  save = errno;
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  if ((sigaction (SIGINT, &intr, (struct sigaction *) NULL) |
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       sigaction (SIGQUIT, &quit, (struct sigaction *) NULL) |
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       UNBLOCK) != 0)
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    {
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      if (errno == ENOSYS)
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        errno = save;
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      else
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        return -1;
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    }
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  return status;
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}
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weak_alias (__libc_system, system)

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