unix编程——管道

管道函数

#inlcude <unistd.h>

int pipe(int fd[2])

上图来自unix网络编程卷二，描述了父子进程通过两个管道进行数据通信。

一个简单父子进程通信的例程：

pipe.h:

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>

void server(int rd,int wr)
{
    char buff[100];
    ssize_t n;
    if((n = read(rd,buff,100)) == 0){
        printf("no chars\n");
        return;
    }
    buff[n] = '\0';
    printf("%s\n",buff);
    write(wr,"Server got it\n",14);
}

void client(int rd,int wr)
{
    int n;
    char buff[100];
    write(wr,"Hello,Server\n",13);
    while((n = read(rd,buff,100)) > 0){
        buff[n] = '\0';
        printf("%s\n",buff);
    }
}

int main()
{
    int fd1[2];
    int fd2[2];
    pipe(fd1);
    pipe(fd2);
    pid_t cldp;
    if((cldp = fork()) == 0){
        close(fd1[1]);
        close(fd2[0]);
        server(fd1[0],fd2[1]);
        exit(0);
    }
    close(fd1[0]);
    close(fd2[1]);
    client(fd2[0],fd1[1]);
    waitpid(cldp,NULL,0);
    exit(0);
}