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