c++基于socket的图片爬虫

超、凢脫俗 2022-06-04 09:12 157阅读 0赞

#include <iostream>
    #include <winsock2.h>
    #include <fstream>
    #include <string>
    #include <sstream>
    using namespace std;
    
    int makeSocket(string url,int port)
    {
        WSADATA wsadata;
        WSAStartup(0x202,&wsadata);
        int sk = socket(AF_INET,SOCK_STREAM,0);
        hostent *host = gethostbyname(url.c_str());
        sockaddr_in saddr;
        saddr.sin_family = AF_INET;
        saddr.sin_port = htons(port);
        memcpy(&saddr.sin_addr,host->h_addr,4);
        if(connect(sk,(sockaddr *)&saddr,sizeof(saddr))==-1)
        {
            cout<<"connect_error"<<endl;
        }
        else
        {
            cout<<"connected"<<endl;
        }
        return sk;
    }
    
    string getName(string name)
    {
        for(int i = 0;i<name.size();i++)
        {
            if(name[i]=='/')
                name[i]='_';
        }
        return name;
    }
    
    void saveImg(SOCKET sk,string url,string name)
    {
    
        string request = "GET "+name;
        request += " HTTP/1.1\r\n";
        request += "Host:"+url+"\r\n";
        request += "connection:close\r\n";
        request += "\r\n";
        if(send(sk,request.c_str(),request.size(),0)==SOCKET_ERROR)
        {
            cout<<"send_error"<<endl;
        }
        else
        {
            cout<<"sended"<<endl;
        }
    
        char rebuf[1024];
        int n = -1;
        fstream out;
        out.open("imgs/"+getName(name),ios::out|ios::binary);
        if(!out)
        {
            cout<<"file open ERROR"<<endl;
            return ;
        }
        n = recv(sk,rebuf,sizeof(rebuf)-sizeof(char),0);
        cout<<n<<endl;
    
    
        char* cpos = strstr(rebuf, "\r\n\r\n");//7
        out.write(cpos + strlen("\r\n\r\n"), n - (cpos - rebuf) - strlen("\r\n\r\n"));
    
    
        while((n=recv(sk,rebuf,sizeof(rebuf)-sizeof(char),0))>0)
        {
            //cout<<n<<endl;
            out.write(rebuf,n);
            //html += rebuf;
            //html += "\r\n";
        }
        out.close();
        closesocket(sk);
    }
    
    void urlHandle(string url,string &uri,string &content)
    {
        int pos = url.find_first_of('/');
        uri = url.substr(0,pos);
        content = url.substr(pos,url.size());
    }
    
    string getHtml(string url)
    {
        string uri,content;
        urlHandle(url,uri,content);
    
        SOCKET skimg = makeSocket(uri,80);
        string data = "GET "+content +" HTTP/1.1\r\n";
        data += "Host:"+uri + "\r\n";
        data += "connection:close\r\n";
        data += "\r\n";
        if(send(skimg,data.c_str(),data.size(),0)==SOCKET_ERROR)
        {
            cout<<"SEND error"<<endl;
        }
        else
        {
            cout<<"sended"<<endl;
        }
        string html;
        char buf[1024*5];
        int n = 0;
        while((n=recv(skimg,buf,sizeof(buf)-sizeof(char),0))!=0)
        {
            for(int i = 0;i<n;i++)
            {
                html += buf[i];
            }
        }
        closesocket(skimg);
        return html;
    }
    
    string reg(string line,string head,string rear)
    {
        int a = line.find(head);
        int b = line.find(rear,1);
        if(a==-1||b==-1)
            return "";
        return line.substr(a+head.size(),b-a-head.size());
    }
    
    int getImgsUrl(string html,string imgsUrl[])
    {
        int i = 0;
        stringstream ss;
        ss<<html;
        string line;
        while(getline(ss,line))
        {
            string res = reg(line,"</strong><a href=\"","\" title");
            if(res!="")
            {
                imgsUrl[i] = res;
                i++;
            }
        }
        return i;
    }
    
    int getAnImgUrl(string html,string imgUrl[])
    {
        int i = 0;
        stringstream ss;
        ss<<html;
        string line;
        while(getline(ss,line,';'))
        {
            string res = reg(line,"<br><img src=\"http:\/\/","\" >&nbsp");
            if(res!="")
            {
                imgUrl[i] = res;
                i++;
            }
        }
        return i;
    }
    
    
    int main()
    {
        string imgType = "www.46eh.com/html/part/17_5.html";
        string html = getHtml(imgType);
        //cout<<html<<endl;
        string imgsUrl[100];
        int n = getImgsUrl(html,imgsUrl);
        for(int i = 0;i<n;i++)
        {
            cout<<i<<"   "<<imgsUrl[i]<<endl;
        }
        string uri,content;
        urlHandle(imgType,uri,content);
        for(int i = 0;i<n;i++)
        {
            string imgsHtml = getHtml(uri + imgsUrl[i]);
            //cout<<imgsHtml<<endl;
            string animgs[100];
            int ans = getAnImgUrl(imgsHtml,animgs);
            for(int i = 0;i<ans;i++)
            {
                cout<<animgs[i]<<endl;
                string uri,content;
                urlHandle(animgs[i],uri,content);
                SOCKET sk = makeSocket(uri,80);
                if(sk==-1)
                    continue;
                saveImg(sk,uri,content);
                //closesocket(sk);
            }
        }
    }

![这里写图片描述][SouthEast]

#include <winsock2.h>引入以后socket相关函数还是无法使用，这是因为没有ws2_32.dll

codeblockes引入ws2\_32.dll

[SouthEast]: /images/20220604/e183f4e58f3a4e0db58d290bafbcc859.png