TCP编程步骤总结:
TCP编程的服务器端一般步骤是:
1、创建一个socket,用函数socket(); SOCKET SocketListen =socket(AF_INET,SOCK_STREAM, IPPROTO_TCP);
2、设置socket属性,用函数setsockopt(); * 可选
3、绑定IP地址、端口等信息到socket上,用函数bind(); SOCKET_ERROR = bind(SocketListen,(const sockaddr*)&addr,sizeof(addr))
4、开启监听,用函数listen(); SOCKET_ERROR == listen(SocketListen,2)
5、接收客户端上来的连接,用函数accept(); SOCKET SocketWaiter = accept(SocketListen,
_Out_ struct sockaddr *addr
Inout int addrlen);
6、收发数据,用函数send()和recv(),或者read()和write();
7、关闭网络连接; closesocket(SocketListen);closesocket(SocketWaiter);
8、关闭监听;
SOCK_STREAM这种的特点是面向连接的,即每次收发数据之前必须通过connect建立连接,而SOCK_DGRAM这种是User Datagram Protocol协议的网络通讯,它是无连接的,不可靠的。
TCP编程的客户端一般步骤是:
1、创建一个socket,用函数socket();
2、设置socket属性,用函数setsockopt(); 可选
3、绑定IP地址、端口等信息到socket上,用函数bind();* 可选
4、设置要连接的对方的IP地址和端口等属性;
5、连接服务器,用函数connect();
6、收发数据,用函数send()和recv(),或者read()和write();
7、关闭网络连接;
//客户端
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/shm.h>
#define MYPORT 8887
#define BUFFER_SIZE 1024
int main()
{
///定义sockfd
int sock_cli = socket(AF_INET,SOCK_STREAM, 0);
///定义sockaddr_in
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(MYPORT); ///服务器端口
servaddr.sin_addr.s_addr = inet_addr("127.0.0.1"); ///服务器ip
///连接服务器,成功返回0,错误返回-1
if (connect(sock_cli, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0)
{
perror("connect");
exit(1);
}
char sendbuf[BUFFER_SIZE];
char recvbuf[BUFFER_SIZE];
while (fgets(sendbuf, sizeof(sendbuf), stdin) != NULL)
{
send(sock_cli, sendbuf, strlen(sendbuf),0); ///发送(write)
if(strcmp(sendbuf,"exit\n")==0)
break;
recv(sock_cli, recvbuf, sizeof(recvbuf),0); ///接收(read)
fputs(recvbuf, stdout);
memset(sendbuf, 0, sizeof(sendbuf));
memset(recvbuf, 0, sizeof(recvbuf));
}
close(sock_cli);
return 0;
}
//服务器端
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/shm.h>
#define MYPORT 8887
#define QUEUE 20
#define BUFFER_SIZE 1024
int main()
{
///定义sockfd
int server_sockfd = socket(AF_INET,SOCK_STREAM, 0);
///定义sockaddr_in
struct sockaddr_in server_sockaddr;
server_sockaddr.sin_family = AF_INET;
server_sockaddr.sin_port = htons(MYPORT);
server_sockaddr.sin_addr.s_addr = htonl(INADDR_ANY);
///bind,成功返回0,出错返回-1
if(bind(server_sockfd,(struct sockaddr *)&server_sockaddr,sizeof(server_sockaddr))==-1)
{
perror("bind");
exit(1);
}
///listen,成功返回0,出错返回-1
if(listen(server_sockfd,QUEUE) == -1)
{
perror("listen");
exit(1);
}
///客户端套接字
char buffer[BUFFER_SIZE];
struct sockaddr_in client_addr;
socklen_t length = sizeof(client_addr);
///成功返回非负描述字,出错返回-1
int conn = accept(server_sockfd, (struct sockaddr*)&client_addr, &length);
if(conn<0)
{
perror("connect");
exit(1);
}
while(1)
{
memset(buffer,0,sizeof(buffer));
int len = recv(conn, buffer, sizeof(buffer),0);
if(strcmp(buffer,"exit\n")==0)
break;
fputs(buffer, stdout);
send(conn, buffer, len, 0);
}
close(conn);
close(server_sockfd);
return 0;
}