/*waitpid.c*/
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

int main()
{
	pid_t pc,pr;
	pc=fork();
	if(pc<0)
		printf("Error fork.\n");
	else if(pc==0){ 
		sleep(5);  
		exit(0);
	}  
	else{ 
		do{ 
			pr=waitpid(pc,NULL,WNOHANG);  
			if(pr==0){ 
				printf("The child process has not exited\n");
				sleep(1);  
			}
		}while(pr==0);
		if(pr==pc)  
			printf("Get child %d\n",pr);
		else
			printf("some error occured.\n");
	}
}