使用C++从零开始，自己写一个MiniWeb

第一步：新建项目

1、打开VS点击创建新项目

2、选择空项目并点下一步（切记不能选错项目类型）

3、填写项目名称和路径，点击创建即可

 

新建好后项目是这样的比较干净 

4、右击源文件，点击添加，新建http.cpp文件

第二步：前期准备

在http.cpp最上面引入依赖，并撰写main方法，打印错误日志的方法

#include
#include
#include
#include
#include
#pragma comment(lib,"WS2_32.lib")
#define PRINTF(str) printf("[%s - %d]"#str"%s",__func__,__LINE__,str);

//打印错误日志
void error_die(const char* str) {
	perror(str);
	exit(1);

}



int main(void) {


	return 0;
}

第三步：网络初始化

初始化可以分为五步：1、网络通讯初始化===>>>2、创建套接字===>>>3、绑定端口===>>>4、绑定套接字===>>>5、创建监听队列

代码实现如下：

int startup(unsigned short *port) {

	//1、网络通讯初始化
	WSADATA data;
	int res = WSAStartup(MAKEWORD(1,1), &data);
	if (res) {
		error_die("init fail");
	}
	//2、创建套接字
	int server_socket = socket(PF_INET,SOCK_STREAM,IPPROTO_TCP);

	if (server_socket == -1) {
		error_die("sock create fail");
	}

	//3、绑定端口
	int opt = 1;
	res = setsockopt(server_socket,SOL_SOCKET,SO_REUSEADDR,(const char*) & opt, sizeof(opt));

	if (res) {
		error_die("port bing fail");
	}

	//4、绑定套接字
	struct sockaddr_in server_addr;
	memset(&server_addr,0,sizeof(server_addr));
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(*port);
	server_addr.sin_addr.s_addr = htonl(INADDR_ANY);

	res = bind(server_socket,(struct sockaddr*) &server_addr, sizeof(server_addr));

	if (res<0) {
		error_die("sock bing fail");
	}

	//5、创建监听队列
	int nameLen = sizeof(server_addr);
	if (*port == 0) {
		res = getsockname(server_socket, (struct sockaddr*)&server_addr,&nameLen);
		if (res) {
			error_die("dynamic sock create fail");
		}

		*port = server_addr.sin_port;
	}


	res = listen(server_socket, 5);
	if (res < 0) {
		error_die("listen queque create fail");
	}
	return server_socket;

};

main方法修改如下:

int main(void) {
	//1、初始化
	unsigned short port = 8000;
	int server_sock = startup(&port);
	printf("http have benn started ,listening [%d] port...",port);

	return 0;
}

第四步：处理用户请求

1、报文背景知识

浏览器发起新的访问时，会向服务器端发送一个请求报文。例如，在浏览器地址输入 127.0.0.1:8000 回车后，服务器端收到的完整报文如下：

GET / HTTP/1.1\n
Host: 127.0.0.1:8000\n
Connection: keep-alive\n
Cache-Control: max-age=0\n
Upgrade-Insecure-Requests: 1\n
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36\n
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9\n
Sec-Fetch-Site: none\n
Sec-Fetch-Mode: navigate\n
Sec-Fetch-User: ?1\n
Sec-Fetch-Dest: document\n
Accept-Encoding: gzip, deflate, br\n
Accept-Language: zh-CN,zh;q=0.9\n
\n

请求报文由4四个部分组成：请求行、请求头部行、空行、请求数据。具体格式如下：

2、具体处理

具体处理代码如下：

//从指定的客户端套接字读取一行数据，保持到buff中，返回实际读取到了字节数
int get_line(int sock, char* buff, int size) {
	char c = 0;
	int i = 0;
	while (i < size - 1 && c != '\n') {
		int n = recv(sock, &c, 1, 0);
		if (n > 0) {
			if (c == '\r') {
				n = recv(sock, &c, 1, MSG_PEEK);
				if (n > 0 && c == '\n') {
					recv(sock, &c, 1, 0);
				}
				else {

					c = '\n';
				}
			}
			buff[i++] = c;
		}
		else {

			c = '\n';
		}
	}
	buff[i] = 0;
	return 0;
}

//向指定套接字，发送一个未支持提示还没有实现的错误页面
void unimplement(int client) {
	
char buf[1024];
 
    sprintf(buf, "HTTP/1.0 501 Method Not Implemented\r\n");
    send(client, buf, strlen(buf), 0);
 
    sprintf(buf, SERVER_STRING);
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "Content-Type: text/html\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "
HTTP request method not supported.\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "\r\n");
    send(client, buf, strlen(buf), 0);

}

//向指定套接字，发送一个未支持提示还没有实现的错误页面
void not_found(int client) {
	
char buf[1024];
 
    sprintf(buf, "HTTP/1.0 404 NOT FOUND\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, SERVER_STRING);
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "Content-Type: text/html\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "
The server could not fulfill\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "your request because the resource specified\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "is unavailable or nonexistent.\r\n");
    send(client, buf, strlen(buf), 0);
    sprintf(buf, "\r\n");
    send(client, buf, strlen(buf), 0);

}




//发送响应的头信息
void headers(int client) {
	
	char buff[1024];
	strcpy(buff, "HTTP/1.0 200 OK\r\n");
	send(client, buff, strlen(buff), 0);


	strcpy(buff, "Server:MyHttpd/0.1\r\n");
	send(client, buff, strlen(buff), 0);

	strcpy(buff, "Content-type:text/html\n");
	send(client, buff, strlen(buff), 0);


	strcpy(buff, "\r\n");
	send(client, buff, strlen(buff), 0);

}


//发送文件
void cat(int client,FILE* resource) {
	char buff[4096];
	int count = 0;
	while (1) {
		int ret = fread(buff, sizeof(char), sizeof(buff), resource);
		if (ret <= 0) {
			break;
		}
		send(client, buff, ret, 0);
		count += ret;
	}
	printf("total send [%d] to client\n",count);
}




void server_file(int client,const char* fileName) {
	char numchars = 1;
	char buff[1024];
	while (numchars > 0 && strcmp(buff, "/n")) {
		numchars = get_line(client, buff, sizeof(buff));
		PRINTF(buff);
	}

	FILE*  resource = fopen(fileName,"r");

	if (resource==NULL) {
		not_found(client);
	}
	else {
		//发送头信息
		headers(client);
		//发送文件
		cat(client, resource);

		printf("file send success");

	}
	fclose(resource);

}



DWORD WINAPI accept_request(LPVOID arg) {
	char buff[1024];
	int client = (SOCKET)arg;
	//1、获取第一行
	int numchars = get_line(client, buff,sizeof(buff));
	PRINTF(buff);
	
	char method[255];
	int j = 0 ,i =0;
	while (!isspace(buff[j])&&i < sizeof(method)-1) {
		method[i++] = buff[j++];
	}
	method[i] = 0;
	PRINTF(method);


	//2、检查请求方法是否支持
	if (stricmp(method,"GET")&& stricmp(method, "POST")) {
		//向浏览器返回错误提示页面
		unimplement(client);
		return 0;
	}


	//3、解析资源路径
	char url[255];
	i = 0;
	while (isspace(buff[j]) && j < sizeof(buff)) {
		j++;
	}
	while (!isspace(buff[j])&& sizeof(url)-1 && j < sizeof(buff)) {
		url[i++] = buff[j++];
	}
	url[i] = 0;
	PRINTF(url);

	char path[512] = "";
	sprintf(path, "htdocs%s", url);
	if (path[strlen(path)-1]=='/') {
		strcat(path, "index.html");

	}
	PRINTF(path);

	struct stat status ;
	if (stat(path,&status)==-1) {
		//把请求包里的东西读完
		while (numchars>0&&strcmp(buff,"/n")) {
			numchars = get_line(client, buff, sizeof(buff));
		}
		PRINTF(buff);
		not_found(client);
	}else {
		if ((status.st_mode & S_IFMT)==S_IFDIR) {
			strcat(path, "index.html");
		}
		server_file(client,path);
	}

	closesocket(client);

	return 0;
}

github地址：

https://github.com/1756336885/miniWeb.git

gitee地址：

miniWeb: 迷你版的web,用C++撰写，后期会添加数据库，中间件相关的操作

参考文章：

2-创建项目_哔哩哔哩_bilibili

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