使用C++从零开始，自己写一个MiniWeb

2024-02-28 前端 0

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<stdio.h>#include<string.h>#include<WinSock2.h>#include<sys/types.h>#include<sys/stat.h>#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, "<HTML><HEAD><TITLE>Method Not Implemented/r/n");    send(client, buf, strlen(buf), 0);    sprintf(buf, "</TITLE></HEAD>/r/n");    send(client, buf, strlen(buf), 0);    sprintf(buf, "<BODY><P>HTTP request method not supported./r/n");    send(client, buf, strlen(buf), 0);    sprintf(buf, "</BODY></HTML>/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, "<HTML><TITLE>Not Found</TITLE>/r/n");    send(client, buf, strlen(buf), 0);    sprintf(buf, "<BODY><P>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, "</BODY></HTML>/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