fork笔记

#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
	pid_t result;
	result=fork();
	if(result==-1){
	//	perrer("fork");
		exit;
	}else if(result==0){
		printf("result=%d,ppid=%d,pid=%d\n",result,getppid(),getpid());
	}else{
		printf("result=%d,ppid=%d,pid=%d\n",result,getppid(),getpid());
	}
}

#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
	pid_t result;
	result=fork();
	if(result==-1){
	//	perrer("fork");
		exit;
	}else if(result==0){
		printf("result=%d,ppid=%d,pid=%d\n",result,getppid(),getpid());
		if(execlp("ps","ps","-ef",NULL)<0){
			printf("error");
			exit;
		}
	}else{
		printf("result=%d,ppid=%d,pid=%d\n",result,getppid(),getpid());
	}
}