UNP --- 第一章 介绍

 1 #include "unp.h"
 2 
 3 int main(int argc, char **argv)
 4 {
 5     int sockfd, n;
 6     char recvline[MAXLINE + 1];
 7     struct sockaddr_in servaddr;
 8 
 9     if (argc != 2)
10     {
11         err_quit("usage: a.out <IPaddress>");
12     }
13     if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
14     {
15         err_sys("socket error");
16     }
17 
18     bzero(&servaddr, sizeof(servaddr));
19     servaddr.sin_family = AF_INET;
20     servaddr.sin_port = htons(13);
21     if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) <= 0)
22     {
23         err_quit("inet_pton error for %s", argv[1]);
24     }
25     if (connect(sockfd, (SA *)&servaddr, sizeof(servaddr)) < 0)
26     {
27         err_sys("connect error");
28     }
29 
30     while ((n = read(sockfd, recvline, MAXLINE)) > 0)
31     {
32         recvline[n] = 0;
33         if (fputs(recvline, stdout) == EOF)
34         {
35             err_sys("fputs error");
36         }
37     }
38     if (n < 0)
39     {
40         err_sys("read error");
41     }
42 }

int Socket(int family, int type, int protocol)
{
    int n;
    if((n = socket(family, type, protocol)) < 0)
        err_sys("socket error");
    return n;
}

#include "unp.h"
#include <time.h>

int main(int argc, char* argv[])
{
    int listenfd, connfd;
    struct sockaddr_in servaddr;
    char buff[MAXLINE + 1];
    time_t ticks;

    listenfd = Socket(AF_INET, SOCK_STREAM, 0);
    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(13);

    Bind(listenfd, (SA*)&servaddr, sizeof(servaddr));
    Listen(listenfd, LISTENQ);

    while(1) {
        connfd = Accept(listenfd, NULL, NULL);
        ticks = time(NULL);
        snprintf(buff, sizeof(buff), "%.24s\r\n", ctime(&ticks));
        Write(connfd, buff, strlen(buff));
        Close(connfd);
    }
}