¹ÜµÀpipe——Linuxѧϰ±Ê¼Ç

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££i nclude <unistd.h>
int pipe(int filedes[2]); //´´½¨¹ÜµÀ
pipe()˵Ã÷:
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#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;
    int r_num;
    memset(buf_r,0,sizeof(buf_r));
    //´´½¨¹ÜµÀ
    if(pipe(pipe_fd)<0){
        printf("pipe create error\n");
        return -1;
    }
    if((pid=fork())==0){//±íʾÔÚ×Ó½ø³ÌÖÐ
        printf("\n");
        //¹Ø±Õ¹ÜµÀдÃèÊö·û£¬½øÐйܵÀ¶Á²Ù×÷
        close(pipe_fd[1]);
        sleep(2);
        //¹ÜµÀÃèÊö·ûÖжÁÈ¡
        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);
        }
        close(pipe_fd[0]);
        exit(0);
    }
    else if(pid>0){
//±íʾÔÚ¸¸½ø³ÌÖУ¬¸¸½ø³Ìд
   
//¹Ø±Õ¹ÜµÀ¶ÁÃèÊö·û£¬½øÐйܵÀд²Ù×÷
        close(pipe_fd[0]);
        if(write(pipe_fd[1],"He