pipe_rw.c

关于进程间通信的代码集锦2

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

int main()
{
	int pipe_fd[2];
	pid_t pid;
	char buf_r[100];
	char* p_wbuf;/*写buffer的指针*/
	int r_num;
	memset(buf_r,0,sizeof(buf_r));/*清0*/
	if(pipe(pipe_fd)<0)
	{
	printf("pipe create error\n");
	return -1;
	}
	if((pid=fork())==0)/*在子进程中*/
	{
		printf("\n");
		close(pipe_fd[1]);/*关闭写描述符*/
		sleep(2);
		if((r_num=read(pipe_fd[0],buf_r,100))>0){
			printf(   "%d numbers read from the pipe is %s\n",r_num,buf_r);
		}	/*父进程写子进程读*/
		close(pipe_fd[0]);
		exit(0);
  	}
	else if(pid>0)
	{
		close(pipe_fd[0]); 
		if(write(pipe_fd[1],"Hello",5)!=-1)
			printf("parent write1 success!\n");
		if(write(pipe_fd[1]," Pipe",5)!=-1)
			printf("parent write2 success!\n");
		close(pipe_fd[1]);
		sleep(3);  /*休眠3s*/
		waitpid(pid,NULL,0); /*在父进程中等待子进程的退出*/
		exit(0);
	}/*等2秒后读，等3秒后退出*/
}