src/process/system.c

   1 #include <unistd.h>
   2 #include <stdlib.h>
   3 #include <signal.h>
   4 #include <sys/wait.h>
   5 #include <spawn.h>
   6 #include <errno.h>
   7 #include "pthread_impl.h"
   8 #include "libc.h"
   9
  10 extern char **__environ;
  11
  12 int system(const char *cmd)
  13 {
  14         pid_t pid;
  15         sigset_t old, reset;
  16         struct sigaction sa = { .sa_handler = SIG_IGN }, oldint, oldquit;
  17         int status = -1, ret;
  18         posix_spawnattr_t attr;
  19
  20         pthread_testcancel();
  21
  22         if (!cmd) return 1;
  23
  24         sigaction(SIGINT, &sa, &oldint);
  25         sigaction(SIGQUIT, &sa, &oldquit);
  26         sigaddset(&sa.sa_mask, SIGCHLD);
  27         sigprocmask(SIG_BLOCK, &sa.sa_mask, &old);
  28
  29         sigemptyset(&reset);
  30         if (oldint.sa_handler != SIG_IGN) sigaddset(&reset, SIGINT);
  31         if (oldquit.sa_handler != SIG_IGN) sigaddset(&reset, SIGQUIT);
  32         posix_spawnattr_init(&attr);
  33         posix_spawnattr_setsigmask(&attr, &old);
  34         posix_spawnattr_setsigdefault(&attr, &reset);
  35         posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGDEF|POSIX_SPAWN_SETSIGMASK);
  36         ret = posix_spawn(&pid, "/bin/sh", 0, &attr,
  37                 (char *[]){"sh", "-c", (char *)cmd, 0}, __environ);
  38         posix_spawnattr_destroy(&attr);
  39
  40         if (!ret) while (waitpid(pid, &status, 0)<0 && errno == EINTR);
  41         sigaction(SIGINT, &oldint, NULL);
  42         sigaction(SIGQUIT, &oldquit, NULL);
  43         sigprocmask(SIG_SETMASK, &old, NULL);
  44
  45         if (ret) errno = ret;
  46         return status;
  47 }