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Diffstat (limited to 'sysdeps/posix/system.c')
| -rw-r--r-- | sysdeps/posix/system.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/sysdeps/posix/system.c b/sysdeps/posix/system.c new file mode 100644 index 0000000000..69b004bb41 --- /dev/null +++ b/sysdeps/posix/system.c @@ -0,0 +1,145 @@ +/* Copyright (C) 1991, 1992, 1994 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <ansidecl.h> +#include <stddef.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/wait.h> +#include <signal.h> +#include <sys/types.h> + + +#ifndef HAVE_GNU_LD +#define __environ environ +#endif + +#define SHELL_PATH "/bin/sh" /* Path of the shell. */ +#define SHELL_NAME "sh" /* Name to give it. */ + +/* Execute LINE as a shell command, returning its status. */ +int +DEFUN(system, (line), register CONST char *line) +{ + int status, save; + pid_t pid; + struct sigaction sa, intr, quit; +#ifndef WAITPID_CANNOT_BLOCK_SIGCHLD + sigset_t block, omask; +#endif + + if (line == NULL) + return 1; + + sa.sa_handler = SIG_IGN; + sa.sa_flags = 0; + __sigemptyset (&sa.sa_mask); + + if (__sigaction (SIGINT, &sa, &intr) < 0) + return -1; + if (__sigaction (SIGQUIT, &sa, &quit) < 0) + { + save = errno; + (void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL); + errno = save; + return -1; + } + +#ifndef WAITPID_CANNOT_BLOCK_SIGCHLD + +/* SCO 3.2v4 has a bug where `waitpid' will never return if SIGCHLD is + blocked. This makes it impossible for `system' to be implemented in + compliance with POSIX.2-1992. They have acknowledged that this is a bug + but I have not seen nor heard of any forthcoming fix. */ + + __sigemptyset (&block); + __sigaddset (&block, SIGCHLD); + save = errno; + if (__sigprocmask (SIG_BLOCK, &block, &omask) < 0) + { + if (errno == ENOSYS) + errno = save; + else + { + save = errno; + (void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL); + (void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL); + errno = save; + return -1; + } + } +#define UNBLOCK __sigprocmask (SIG_SETMASK, &omask, (sigset_t *) NULL) +#else +#define UNBLOCK 0 +#endif + + pid = __vfork (); + if (pid == (pid_t) 0) + { + /* Child side. */ + CONST char *new_argv[4]; + new_argv[0] = SHELL_NAME; + new_argv[1] = "-c"; + new_argv[2] = line; + new_argv[3] = NULL; + + /* Restore the signals. */ + (void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL); + (void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL); + (void) UNBLOCK; + + /* Exec the shell. */ + (void) __execve (SHELL_PATH, (char *CONST *) new_argv, __environ); + _exit (127); + } + else if (pid < (pid_t) 0) + /* The fork failed. */ + status = -1; + else + /* Parent side. */ +#ifdef NO_WAITPID + { + pid_t child; + do + { + child = __wait (&status); + if (child <= -1) + { + status = -1; + break; + } + } while (child != pid); + } +#else + if (__waitpid (pid, &status, 0) != pid) + status = -1; +#endif + + save = errno; + if ((__sigaction (SIGINT, &intr, (struct sigaction *) NULL) | + __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL) | + UNBLOCK) != 0) + { + if (errno == ENOSYS) + errno = save; + else + return -1; + } + + return status; +} |