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使用C++从零开始，自己写一个MiniWeb

news 来源：原创 2024/5/20 6:55:42

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