C++ TCP网络编程详细讲解

int sockfd = socket(AF_INET, SOCK_STREAM, 0);

int connect(int socket, const struct sockaddr *address, socklen_t address_len)

ssize_t send(int socket, const void *buffer, size_t length, int flags)

ssize_t recv(int socket, void *buffer, size_t length, int flags);

#include <unistd.h>
int close(int fildes);

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <arpa/inet.h>
int main(int arGC, char const *argv[])
{
	//创建tcp套接字 SOCK_STREAN
	int sockfd = socket(AF_INET, SOCK_STREAM, 0);
	//connect连接服务器（知道服务器地址信息）
	struct sockaddr_in ser_addr;
	bzero(&ser_addr, sizeof(ser_addr));
	ser_addr.sin_family = AF_INET;
	ser_addr.sin_port = htons(8000);
	ser_addr.sin_addr.s_addr = inet_addr("10.9.21.211");
	connect(sockfd, (struct sockaddr *)&ser_addr, sizeof(ser_addr));
	//客户端发送请求
	send(sockfd, "hello tcp", strlen("hello tcp"), 0 );
	//客户端接收服务器的应答
	unsigned char buf[1500] = "";
	int len = recv(sockfd, buf, sizeof(buf), 0);
	printf("服务器的应答：%s\n", buf);
	//关闭套接字
	close(sockfd);
	return 0;
}

int sockfd = socket(AF_INET, SOCK_STREAM, 0);

struct sockaddr_in my_addr;
bzero(&my_addr, sizeof(my_addr)):
my_addr.sin_family = AF_INET;
my_addr.sin_port = htons(8000);
my_addr.sin_addr.s_addr = htonl(INADDR_ANY);
bind(sockfd, (struct sockaddr *)&my_addr, sizeof(my_addr)):

#include <sys/socket.h>
int listen(int socket, int backlog);

#include <sys/socket.h>
int accept(int sockfd,struct sockaddr *cliaddr, socklen_t *addrlen);

ssize_t send(int socket, const void *buffer, size_t length, int flags)

ssize_t recv(int socket, void *buffer, size_t length, int flags);

#include <unistd.h>
int close(套接字);

#include <stdio.h>
#include <sys/socket.h> //socket
#include <netinet/in.h> //struct sockaddr_in
#include <string.h>     //memset
#include <arpa/inet.h>  //htos
#include <unistd.h>     //close
int main()
{
    //创建套接字
    int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if(sockfd < 0)
	{
		perror("cockt");
		return 0;
	}
    //bind绑定固定的port、ip地址信息
    struct sockaddr_in my_addr;
    bzero(&my_addr, sizeof(my_addr));
    my_addr.sin_family = AF_INET;
    my_addr.sin_port = htons(9000);
    my_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    int ret = bind(sockfd, (struct sockaddr *)&my_addr, sizeof(my_addr));
	if(ret == -1)
	{
		perror("bind");
		return 0;
	}
	//监听套接字 创捷连接队列
	ret = listen(sockfd, 10);
	if(ret == -1)
	{
		perror("listen");
		return 0;
	}
	//提取客户端的连接
	while(1)
	{
		//一次只能提取一个客户端
		struct sockaddr_in cli_addr;
		socklen_t cli_len = sizeof(cli_addr);
		int cfd = accept(sockfd, (struct sockaddr *)&cli_addr, &cli_len);
		if(cfd < 0 ) //提取失败
		{
			perrer("accept\n");
			break;
		}
		else
		{
			char ip[16] = "";
			unsigned short port = 0;
			inet_ntop(AF_INET, &cli_addr.sin_addr.s_addr, ip, 16);
			port = ntohs(cli_addr.sin_port);
			//打印客户端的信息
			printf("客户端：%s %d connected\n", ip, port);
			while(1)
			{
				//获取客户端的请求
				unsigned char buf[1500] = "";
				int len = recv(cfd, buf, sizeof(buf), 0);
				if(len == 0) //客户端已经关闭
				{
					//关闭与客户端连接的套接字
					close(cfd);
					break;
				}
				//应答客户端
				send(cfd, buf, len, 0);
			}
		}	
	}
	//关闭监听套接字
	close(sockfd);
	return 0;
}