学步园

Linux平台下基于TCP/IP协议的C++网络编程初步
实验平台：Ubuntu(Linux)
开发工具：Eclipse+CDT

作者：@郑海波 

http://blog.csdn.net/nuptboyzhb/

特点：
1.基于Linux平台的网络编程，最重要的特点是要调用Linux的API函数。这是与windows平台最大的不同。
2.我们将发送的消息封装成结构体，增添了其传递消息的复杂性。

3.我们用的是socket编程，没有用ACE网络编程。
服务器：
[c++ code]

/*
 * MyMain.cpp
 *
 *  Created on: 2012-9-19
 *      Author: zhb
 */
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <unistd.h>
#define SERVPORT 3333
#define BACKLOG 10
#define MAXSIZE 1024
/*
 *自定义信息
 */
typedef struct MyMessage{
    int ID;
    char info[256];
}MyMessage,*pMyMessage;
int main() {
	int sockfd, client_fd;
	struct sockaddr_in my_addr;
	struct sockaddr_in remote_addr;
	//创建套接字
	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
		perror("socket create failed!");
		exit(1);
	}
	//绑定端口地址
	my_addr.sin_family = AF_INET;
	my_addr.sin_port = htons(SERVPORT);
	my_addr.sin_addr.s_addr = INADDR_ANY;
	bzero(&(my_addr.sin_zero), 8);
	if (bind(sockfd, (struct sockaddr*) &my_addr, sizeof(struct sockaddr))== -1) {
		perror("bind error!");
		exit(1);
	}
	//监听端口
	if (listen(sockfd, BACKLOG) == -1) {
		perror("listen error");
		exit(1);
	}

	while (1) {
		//int sin_size = sizeof(struct sockaddr_in);
		socklen_t sin_size = sizeof(struct sockaddr_in);
		if ((client_fd = accept(sockfd,(struct sockaddr*) &remote_addr,&sin_size)) == -1){
			perror("accept error!");
			continue;
		}
		printf("Received a connection from %s\n", (char*)inet_ntoa(remote_addr.sin_addr));

		//子进程段
		if (!fork()){
			//接受client发送的请示信息
			int rval;
			char buf[MAXSIZE];
			if ((rval = read(client_fd, buf, MAXSIZE)) < 0) {
				perror("reading stream error!");
				continue;
			}
			printf("%s\n", buf);
			//向client发送信息
			//char* msg = "Hello,Mr hqlong, you are connected!\n";
			MyMessage data;
			memset((void *)&data,0,sizeof(MyMessage));
			data.ID=123;
			strcpy(data.info,"This message come from ServSocket!");
			if(send(client_fd,(void*)&data,sizeof(MyMessage),0) == -1){
				perror("send error!");
			}
			close(client_fd);
			exit(0);
		}
		close(client_fd);
	}
	return 0;
}

客户端：
[c++ code]

/*
 * MyMainClient.cpp
 *
 *  Created on: 2012-9-19
 *      Author: zhb
 */
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <unistd.h>
#define SERVPORT 3333
#define MAXDATASIZE 100
#define SERVER_IP "127.0.0.1"
#define DATA  "this is a client message"
/*
 *自定义信息
 */
typedef struct MyMessage{
    int ID;
    char info[256];
}MyMessage,*pMyMessage;
int main(int argc, char* argv[]) {
	int sockfd, recvbytes;
	//char buf[MAXDATASIZE];
	MyMessage recvData;
	struct sockaddr_in serv_addr;

	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
		perror("socket error!");
		exit(1);
	}
	bzero(&serv_addr, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_port = htons(SERVPORT);
	serv_addr.sin_addr.s_addr = inet_addr(SERVER_IP);

	if (connect(sockfd, (struct sockaddr *) &serv_addr, sizeof(struct sockaddr))== -1) {
		perror("connect error!");
		exit(1);
	}
	write(sockfd, DATA, sizeof(DATA));
	memset((void *)&recvData,0,sizeof(MyMessage));
	if ((recvbytes = recv(sockfd, (void *)&recvData,sizeof(MyMessage), 0)) == -1) {
		perror("recv error!");
		exit(1);
	}
	//buf[recvbytes] = '\0';
	printf("Received:ID=%d,Info= %s",recvData.ID,recvData.info);
	close(sockfd);
	return 0;
}

不足：服务器没有进行多线程处理！当多个Client接入时，应考虑多线程编程。以后继续深入...
相关链接：基于windows平台的TCP/IP协议的C++网络编程：http://blog.csdn.net/nuptboyzhb/article/details/7391150