【整理】Linux Socket网络编程_UDP编程(5)_基础版本

原创文章，转载请注明： 转载自勤奋的小青蛙
本文链接地址: 【整理】Linux Socket网络编程_UDP编程(5)_基础版本

环境：

Centos 6.5+gcc (GCC) 4.8.2+kernel 2.6.32+cmake version 2.8.12.2

实现效果：

采用UDP协议，做一个简单的time server.

服务端代码udp_server.cpp：

#include <netdb.h>
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <memory.h>
#include <signal.h>
#include <time.h>
#include <stdlib.h>
#include <arpa/inet.h>

int sockfd; //套接字

void sig_handler(int signo)
{
	if (signo == SIGINT) {
		printf("Server close\n");
		close(sockfd);
		exit(1);
	}
}

//输出客户端信息
void out_addr(struct sockaddr_in *clientaddr) {
	//将端口从网络字节序转换成主机字节序
	int port = ntohs(clientaddr->sin_port);
	char ip[16];
	memset(ip, 0, sizeof(ip));
	//将ip地址从网络字节序转换成点分十进制
	inet_ntop(AF_INET, &clientaddr->sin_addr.s_addr, ip, sizeof(ip));
	printf("client: %s(%d) connected\n", ip, port);
}

//和客户端进行通信
void do_service() {
	struct sockaddr_in clientaddr;
	socklen_t len = sizeof(clientaddr);
	char buffer[1024];
	memset(buffer, 0, sizeof(buffer));
	// 接收客户端的数据报文
	if (recvfrom(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr*)&clientaddr, &len) < 0) {
		perror("recvfrom error");
	}
	else {
		out_addr(&clientaddr);
		printf("client send into: %s\n", buffer);

		//向客户端发送数据报文
		long int t = time(0);
		char *ptr = ctime(&t);
		size_t size = strlen(ptr) * sizeof(char);
		if (sendto(sockfd, ptr, size, 0, (struct sockaddr *)&clientaddr, len) < 0) {
			perror("sendto error");
		}
	}
}

int main(int argc, char *argv[]) {
	if (argc < 2) {
		printf("usage: %s port\n", argv[0]);
		exit(1);
	}

	if (signal(SIGINT, sig_handler) == SIG_ERR) {
		perror("signal sigint error");
		exit(1);
	}

	/*步骤1:创建socket*/
	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (sockfd < 0) {
		perror("socket error");
		exit(1);
	}

	int ret;
	int opt = 1;
	//设置套接字选项
	if ((ret = setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0)) {
		perror("setsockopt error");
		exit(1);
	}

	/*步骤2:调用bind函数对socket和地址进行绑定*/
	struct sockaddr_in serveraddr;

	memset(&serveraddr, 0, sizeof(serveraddr));
	serveraddr.sin_family = AF_INET; //ipv4
	serveraddr.sin_port = htons(atoi(argv[1])); //port
	serveraddr.sin_addr.s_addr = INADDR_ANY; //ip
	if (bind(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr)) < 0) {
		perror("bind error");
		exit(1);
	}

	/*步骤3:服务端和客户端进行双向通信*/
	while (1) {
		do_service();
	}



	return 0;
}

服务端CMakeLists.txt:

    cmake_minimum_required(VERSION 2.8)
    #project name
    project(socket_demo)

	set(CMAKE_CXX_COMPILER "g++")

    #set compiler for c++ language
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x -pthread -lrt -D_GLIBCXX_USE_NANOSLEEP")

    #source files(can add source files manually)
    #set(SOURCE_FILES main.cpp ThostFtdcMdApi.h ThostFtdcTraderApi.h ThostFtdcUserApiDataType.h ThostFtdcUserApiStruct.h MdSpi.cpp MdSpi.h TdSpi.cpp TdSpi.h CTP_Manager.cpp CTP_Manager.h Login.h Order.cpp Order.h User.cpp User.h Utils.cpp Utils.h DBManager.h DBManager.cpp Trader.h Trader.cpp FutureAccount.h FutureAccount.cpp Strategy.h Strategy.cpp Algorithm.h Algorithm.cpp)

	#source directory(add source files automatically)
	aux_source_directory(. SOURCE_FILES)

    #set extern libraries
    #set(LIBRARIES libthostmduserapi.so libthosttraderapi.so libmongoclient.so libboost_thread.so libboost_system.so libboost_regex.so)

    #add execute file
    add_executable(udp_server ${SOURCE_FILES})

    #add link library
    #target_link_libraries(quant_ctp_XTrader ${LIBRARIES})

客户端代码：

#include <netdb.h>
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <memory.h>
#include <signal.h>
#include <time.h>
#include <stdlib.h>
#include <arpa/inet.h>


int main(int argc, char *argv[]) {
	if (argc < 3) {
		printf("usage: %s ip port\n", argv[0]);
		exit(1);
	}

	/*步骤1:创建socket*/
	int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (sockfd < 0) {
		perror("socket error");
		exit(1);
	}

	/*步骤2:调用recvfrom和sendto等函数和服务器双向通信*/
	struct sockaddr_in server_addr;
	memset(&server_addr, 0, sizeof(server_addr));
	server_addr.sin_family = AF_INET; //ipv4
	server_addr.sin_port = htons(atoi(argv[2])); //port
	inet_pton(AF_INET, argv[1], &server_addr.sin_addr.s_addr); //ip address

	if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
		perror("connect error");
		exit(1);
	}


	char buffer[1024] = "hello gmqh!";
	//向服务器发送数据报文
	//发送方式1:
	/*if (sendto(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
		perror("sendto error");
		exit(1);
	}*/
	//发送方式2:
	if (send(sockfd, buffer, sizeof(buffer), 0) < 0) {
		perror("send error");
		exit(1);
	}
	else {
		//接受服务器端发送的数据报文
		int size;
		memset(buffer, 0, sizeof(buffer));
		if ((size = recv(sockfd, buffer, sizeof(buffer), 0)) < 0) {
			perror("recv error");
			exit(1);
		}
		else
		{
			printf("%s", buffer);
		}
	}
	close(sockfd);

	return 0;
}

客户端CMakeLists.txt:

    cmake_minimum_required(VERSION 2.8)
    #project name
    project(socket_demo)

	set(CMAKE_CXX_COMPILER "g++")

    #set compiler for c++ language
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x -pthread -lrt -D_GLIBCXX_USE_NANOSLEEP")

    #source files(can add source files manually)
    #set(SOURCE_FILES main.cpp ThostFtdcMdApi.h ThostFtdcTraderApi.h ThostFtdcUserApiDataType.h ThostFtdcUserApiStruct.h MdSpi.cpp MdSpi.h TdSpi.cpp TdSpi.h CTP_Manager.cpp CTP_Manager.h Login.h Order.cpp Order.h User.cpp User.h Utils.cpp Utils.h DBManager.h DBManager.cpp Trader.h Trader.cpp FutureAccount.h FutureAccount.cpp Strategy.h Strategy.cpp Algorithm.h Algorithm.cpp)

	#source directory(add source files automatically)
	aux_source_directory(. SOURCE_FILES)

    #set extern libraries
    #set(LIBRARIES libthostmduserapi.so libthosttraderapi.so libmongoclient.so libboost_thread.so libboost_system.so libboost_regex.so)

    #add execute file
    add_executable(udp_client ${SOURCE_FILES})

    #add link library
    #target_link_libraries(quant_ctp_XTrader ${LIBRARIES})

编译方式：