简单unix 局域网的TCP会话

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>

#define maxn 101
/**
服务器端
1>建立一个基于TCP的流套接字描述符
2>将套接字描述符绑定到本地地址和本地端口上
3>监听客户端的请求
4>通过Accept接收客户端的请求
5>发送数据/接收数据
6>关闭套接字
客户端
1>与服务器端建立链接
2> 发送数据/接收数据
3>关闭套接字
**/
int main(int  argc, char** argv)
{
int s_socket, sock_port ;
//1>建立一个基于TCP的流套接字描述符
if((s_socket = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
herror("socket");
exit(errno);
}
else
{
printf("socket create success!\n");
}
//端口号
unsigned int port;
if(argv[2]) {
port = atoi(argv[2]);
}
else {
port = 1111;
}
if(argv[3])
{
sock_port = atoi(argv[3]);
}
else
{
sock_port = 3;
}
//2>将套接字描述符绑定到本地地址和本地端口上
struct sockaddr_in  c_addport, s_addport;
bzero(&s_addport, sizeof(s_addport));
s_addport.sin_family = AF_INET;
//s_addport.sin_addr.s_addr = inet_addr(argv[1]);
s_addport.sin_port = htons(port);
if(argv[1])
{
s_addport.sin_addr.s_addr = inet_addr(argv[1]);
}
else
{
s_addport.sin_addr.s_addr = INADDR_ANY;
}
if((bind(s_socket, (struct sockaddr*) &s_addport, sizeof(struct sockaddr))) == -1) {
perror("bind");
exit(errno);
}
else {
printf("bind success!\n");
}
//3>监听客户端的请求
if(listen(s_socket, sock_port) == -1)
{
herror("listen");
exit(errno);
}
else
{
printf("server is listening!\n");
}
while(1)
{
int  flag;
socklen_t len;
len = sizeof(struct sockaddr);
flag = accept(s_socket, (struct sockaddr*)&c_addport, &len);
if(flag == -1)
{
herror("accept");
exit(errno);
}
else
{
printf("Accept success!\n");
printf("现在监听的客户端IP是 :%s端口是%d\n", inet_ntoa(c_addport.sin_addr), ntohl(c_addport.sin_port));
}
char buf[maxn];
while(1)
{
//发送消息
loop:
bzero(buf, maxn);
printf("请输入要发送的信息:");
fgets(buf, maxn, stdin);
int L_len = strlen(buf);
int Index ;
if(strncasecmp(buf, "exit", 4) == 0)
{
printf("chatting  be ended !\n");
break;
}
if(strcmp(buf, "\n") == 0)
{
printf("空字符\n");
goto loop;
}
if(buf[L_len - 1] == '\n')
{
Index = send(flag, buf, L_len - 1, 0);
}
else
{
Index = send(flag, buf, L_len, 0);
}
if(Index == -1)
{
printf("send message failure!");
}
else
{
printf("send message success\n");
}
//接收消息
bzero(buf, maxn);
int LL;
LL = recv(flag, buf, maxn, 0);
if(LL > 0)
{
printf("从客户端接收的信息是%s\n", buf);
}
else
{
if(LL < 0)
{
printf("Receive message failure!\n");
}
else
{
printf("客户端退出，聊天中止\n");
break;
}
}
}
close(flag);
printf("是否结束进程？Y->是：Ｎ->否");
bzero(buf, maxn);
fgets(buf, maxn, stdin);
if(strncasecmp(buf, "Y", 1) == 0)
{
printf("结束进程\n");
break;
}
else {
printf("waiting ..........\n");
}
}
close(s_socket);
return 0;
}