posix/test-vfork.c

   1 #include <stdio.h>
   2 #include <unistd.h>
   3 #include <error.h>
   4 #include <errno.h>
   5 #include <sys/wait.h>
   6
   7 void noop (void);
   8
   9 #define NR      2       /* Exit code of the child.  */
  10
  11 int
  12 main (void)
  13 {
  14   pid_t pid;
  15   int status;
  16
  17   printf ("Before vfork\n");
  18   fflush (stdout);
  19   pid = vfork ();
  20   if (pid == 0)
  21     {
  22       /* This will clobber the return pc from vfork in the parent on
  23          machines where it is stored on the stack, if vfork wasn't
  24          implemented correctly, */
  25       noop ();
  26       _exit (NR);
  27     }
  28   else if (pid < 0)
  29     error (1, errno, "vfork");
  30   printf ("After vfork (parent)\n");
  31   if (waitpid (0, &status, 0) != pid
  32       || !WIFEXITED (status) || WEXITSTATUS (status) != NR)
  33     exit (1);
  34   exit (0);
  35 }
  36
  37 void
  38 noop ()
  39 {
  40 }