/******************************************************** * An example source module to accompany... * * "Using POSIX Threads: Programming with Pthreads" *     by Brad nichols, Dick Buttlar, Jackie Farrell *     O'Reilly & Associates, Inc. * ******************************************************** * exit_status.c * * Simple code to demonstrate thread exit status */#include <stdlib.h>#include <stdio.h>#include <errno.h>#include <pthread.h>pthread_t thread;static int arg;static const int real_bad_error = -12;static const int normal_error = -10;static const int success = 1;void * routine_x(void *arg_in){  int *arg = (int *)arg_in;  if (*arg == 1) {    pthread_exit((void *)&real_bad_error);  } else if (*arg == 2) {    return ((void *)&normal_error);  } else {    return ((void *)&success);  }}extern intmain(int argc, char **argv){  extern int arg;  pthread_t thread;  void *statusp;  if (argc < 2)    printf("usage: %s [1-3]\n", argv[0]), exit(1);  arg = atoi(argv[1]);  pthread_create(&thread,		 NULL,		 routine_x ,		 &arg);  pthread_join(thread, &statusp);  if (statusp == PTHREAD_CANCELED) {    printf("Thread was canceled.\n");  } else {    printf("Thread completed and exit status is %ld.\n", *(int *)statusp);  }  return 0;}