程序清单8-3 8-4 演示不同的exit值

 //http://blog.chinaunix.net/uid-24549279-id-71355.html
 /*
  ============================================================================
  Name        : test.c
  Author      : blank
  Version     :
  Copyright   : Your copyright notice
  Description : 程序清单8-3 8-4 演示不同的exit值
  ============================================================================
 */

 #include "ourhdr.h"
 #include <sys/wait.h>

 static void pr_exit(int status);

 int main(int argc, char *argv[])
 {
     pid_t    pid;
     int        status;

     if ((pid = fork()) < ){
         err_sys("fork error");
     }else if(pid == ){
         //child
         exit();
     }

     /*
      * wait for child and print its status
      */
     if (wait(&status) != pid){
         err_sys("wait error");
     }

     pr_exit(status);

     /*
      * child generates SIGABRT
      */
     if ((pid = fork()) < ){
         err_sys("fork_error");
     }else if (pid == ){
         abort();
     }

     /*
      * wait for child and print its status
      */
     if (wait(&status) != pid){
         err_sys("wait error");
     }

     pr_exit(status);

     if ((pid = fork()) < ){
         err_sys("fork error");
     }else if(pid == ){
         // child divide by 0 generates SIGFPE
         status/=;
     }

     /*
      * wait for child and print its status
      */
     if (wait(&status) != pid){
         err_sys("wait error");
     }

     pr_exit(status);
 }

 static void pr_exit(int status)
 {
     if (WIFEXITED(status)){
         printf("normal termination, exit status = %d\n", WEXITSTATUS(status));
     }else if (WIFSIGNALED(status)){
         printf("abnormal termination, signal number=%d%s\n", WTERMSIG(status),
 #ifdef WCOREDUMP
         WCOREDUMP(status) ? " (core file generated )" : "");
 #else
         "");
 #endif
     }else if(WIFSTOPPED(status)){
             printf("child stopped, signal number=%d\n", WSTOPSIG(status));
         }
 }