p12-13.c

SUN Solaris8平台下进程间通信

#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <signal.h>
#include <unistd.h>
#include "err_exit.h"
int make_socket(unsigned short int port);
void doit(int);
int main(void)
{
    int server_sockfd, client_sockfd;
    int server_len, client_len;
    struct sockaddr_in client_address;
    server_sockfd = make_socket(2003);
    /* 创建连接队列，忽略子进程终止信号 */
    listen(server_sockfd, 5);
    signal(SIGCHLD, SIG_IGN);
    while(1) {
        printf("server waiting\n");
        /* 接收连接 */
        client_len = sizeof(client_address);
        client_sockfd = accept(server_sockfd, 
            (struct sockaddr *)&client_address, &client_len);
        /* 为这个客户创建一个子进程 */
        if(fork() == 0) {             /* 若为子进程，接收并回答客户的消息 */
            close(server_sockfd);     /* 子进程关闭侦听套接字 */
            doit(client_sockfd);      /* 处理客户的请求 */
            close(client_sockfd);     /* 已处理完该客户的请求 */
            exit(0);                  /* 子进程终止 */
        }
        else {
            close(client_sockfd);     /* 父进程关闭被连接的套接字 */
        }
    }
}
void doit(client_sockfd)
{
char buf[255];
    int n;
    /* 接收并回应客户的消息 */
    n = read(client_sockfd, buf, sizeof(buf));
    sleep(5);                /* 睡眠5秒仅为了演示需要 */
    buf[n] = 0;
    write(client_sockfd, buf, n);
}