child.c

来自「操作系统的一些有用的题目」· C语言 代码 · 共 39 行

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/wait.h>

pid_t pid;

void sig_handler(int signum,siginfo_t *info,void *notused)
{
	if (signum == SIGCHLD) 
		printf("process id %d\n",info->si_pid);
}

int main()
{
	struct sigaction newact,oldact;
	
	newact.sa_sigaction = sig_handler;
	sigemptyset(&newact.sa_mask);
	newact.sa_flags = SA_SIGINFO;
	
	sigaction(SIGCHLD,&newact,&oldact);

	if ((pid = fork()) < 0)
		perror("fork failed\n");
	if (pid) {
		printf("father id %d\n",getpid());
		/* father process */
		while (1);
	} else {
		/* child process */
		sleep(2);
		printf("child id %d\n",getpid());
	}
	return 0;
}