cbits/system.c

   1 /*
   2  * (c) The University of Glasgow 2002
   3  *
   4  * $Id: system.c,v 1.6 2002/03/26 21:02:19 sof Exp $
   5  *
   6  * system Runtime Support
   7  */
   8
   9 /* The itimer stuff in this module is non-posix */
  10 // #include "PosixSource.h"
  11
  12 #include "HsBase.h"
  13
  14 #if defined(mingw32_TARGET_OS)
  15 #include <windows.h>
  16 #include <stdlib.h>
  17 #endif
  18
  19 HsInt
  20 systemCmd(HsAddr cmd)
  21 {
  22   /* -------------------- WINDOWS VERSION --------------------- */
  23 #if defined(mingw32_TARGET_OS) || defined(cygwin32_TARGET_OS)
  24     return system(cmd);
  25 #else
  26   /* -------------------- UNIX VERSION --------------------- */
  27     int pid;
  28     int wstat;
  29
  30     switch(pid = fork()) {
  31     case -1:
  32         if (errno != EINTR) {
  33             return -1;
  34         }
  35     case 0:
  36       {
  37 #ifdef HAVE_SETITIMER
  38         /* Reset the itimers in the child, so it doesn't get plagued
  39          * by SIGVTALRM interrupts.
  40          */
  41         struct timeval tv_null = { 0, 0 };
  42         struct itimerval itv;
  43         itv.it_interval = tv_null;
  44         itv.it_value = tv_null;
  45         setitimer(ITIMER_REAL, &itv, NULL);
  46         setitimer(ITIMER_VIRTUAL, &itv, NULL);
  47         setitimer(ITIMER_PROF, &itv, NULL);
  48 #endif
  49
  50         /* the child */
  51         execl("/bin/sh", "sh", "-c", cmd, NULL);
  52         _exit(127);
  53       }
  54     }
  55
  56     while (waitpid(pid, &wstat, 0) < 0) {
  57         if (errno != EINTR) {
  58             return -1;
  59         }
  60     }
  61
  62     if (WIFEXITED(wstat))
  63         return WEXITSTATUS(wstat);
  64     else if (WIFSIGNALED(wstat)) {
  65         errno = EINTR;
  66     }
  67     else {
  68         /* This should never happen */
  69     }
  70     return -1;
  71 #endif
  72 }