text: #include "orte_config.h"
  
  #include "opal/runtime/opal.h"
  
  #include <stdio.h>
  #include <sys/types.h>
  #include <unistd.h>
  #include <string.h>
  #include <stdlib.h>
  
  #include <mpi.h>
  
  int main(int argc, char* argv[])
  {
      int msg, rc, i;
      MPI_Comm parent, child;
      int rank, size;
      const char *hostname;
      pid_t pid;
      MPI_Info info;
      char *keyval, *tmp;
  
      pid = getpid();
      MPI_Init(NULL, NULL);
      MPI_Comm_rank(MPI_COMM_WORLD, &rank);
      MPI_Comm_size(MPI_COMM_WORLD, &size);
  
      MPI_Comm_get_parent(&parent);
      /* If we get COMM_NULL back, then we're the parent */
      if (MPI_COMM_NULL == parent) {
          if (argc < 2) {
              fprintf(stderr, "Usage: info_spawn key:value key:value...\n");
              exit(1);
          }
  
          pid = getpid();
          printf("Parent [pid %ld] about to spawn!\n", (long)pid);
          MPI_Info_create(&info);
          for (i=1; i < argc; i++) {
              tmp = strdup(argv[i]);
              keyval = strchr(tmp, ':');
              if (NULL == keyval) {
                  fprintf(stderr, "Missing colon separator in key-value\n");
                  exit(1);
              }
              *keyval = '\0';
              keyval++;
              fprintf(stderr, "SETTING %s TO %s\n", tmp, keyval);
              MPI_Info_set(info, tmp, keyval);
              free(tmp);
          }
          if (MPI_SUCCESS != (rc = MPI_Comm_spawn(argv[0], MPI_ARGV_NULL, 3, info,
                                                  0, MPI_COMM_WORLD, &child, MPI_ERRCODES_IGNORE))) {
              printf("Child failed to spawn\n");
              return rc;
          }
          printf("Parent done with spawn\n");
          if (0 == rank) {
              msg = 38;
              printf("Parent sending message to child\n");
              MPI_Send(&msg, 1, MPI_INT, 0, 1, child);
          }
          MPI_Comm_disconnect(&child);
          printf("Parent disconnected\n");
      }
      /* Otherwise, we're the child */
      else {
          MPI_Comm_rank(MPI_COMM_WORLD, &rank);
          MPI_Comm_size(MPI_COMM_WORLD, &size);
          hostname = opal_gethostname();
          pid = getpid();
          printf("Hello from the child %d of %d on host %s pid %ld\n", rank, 3, hostname, (long)pid);
          if (0 == rank) {
              MPI_Recv(&msg, 1, MPI_INT, 0, 1, parent, MPI_STATUS_IGNORE);
              printf("Child %d received msg: %d\n", rank, msg);
          }
          MPI_Comm_disconnect(&parent);
          printf("Child %d disconnected\n", rank);
      }
  
      MPI_Finalize();
      fprintf(stderr, "%d: exiting\n", pid);
      return 0;
  }
  