waitpid，WNOHANG和SIGCHLD的示例

我需要在C中结合使用waitpid ， WNOHANG和SIGCHLD的示例，以及如何在fore \ background中使用它们？

  signal( SIGCHLD, SIG_IGN ); waitpid(child, status, 0); 

Answer 1

取自http://voyager.deanza.edu/~perry/sigchld.html

 #include  /************ Handling SIGCHLD!! ******************/ #include  #include  #include  #include  /***** For waitpid. *****/ #include  /***** For sigsetjmp and siglongjmp. *****/ sigjmp_buf env; main() { pid_t pid; int n = 20; struct sigaction sa; void delete_zombies(void); sigfillset(&sa.sa_mask); sa.sa_handler = delete_zombies; sa.sa_flags = 0; sigaction(SIGCHLD, &sa, NULL); sigsetjmp(env, 1); if ((pid = fork()) < 0) { perror("Bad fork!"); exit(1); } if (pid > 0) /***** Parent *****/ { printf("Created child %ld\n", pid); sleep(n -= 2); kill(0, SIGKILL); } else /***** Child *****/ { sleep(2); exit(0); /****** Not necessary here but... ******/ } } void delete_zombies(void) { pid_t kidpid; int status; printf("Inside zombie deleter: "); while ((kidpid = waitpid(-1, &status, WNOHANG)) > 0) { printf("Child %ld terminated\n", kidpid); } siglongjmp(env,1); }