linux c++模拟简易网络爬虫实例

/** To change this license header, choose License Headers in Project Properties.* To change this template file, choose Tools | Templates* and open the template in the editor.*//* * File: main.cpp* Author: yangchao**/#include <iostream>#include <string>#include <netdb.h>#include <string.h>#include <stdlib.h>using namespace std;void parseHostAndPagePath(const string url,string &hostUrl,string &pagePath){hostUrl=url;pagePath="/";int pos=hostUrl.find("http://");if(-1!=pos)hostUrl=hostUrl.replace(pos,7,"");pos=hostUrl.find("https://");if(-1!=pos)hostUrl=hostUrl.replace(pos,8,"");pos=hostUrl.find("/");if(-1!=pos){pagePath=hostUrl.substr(pos);hostUrl=hostUrl.substr(0,pos);}}string getPageContent(const string url){struct hostent *host;string hostUrl,pagePath;parseHostAndPagePath(url,hostUrl,pagePath);if(0==(host=gethostbyname(hostUrl.c_str()))){cout<<"gethostbyname error/n"<<endl;exit(1);}struct sockaddr_in pin;int port=80;bzero(&pin,sizeof(pin));pin.sin_family=AF_INET;pin.sin_port=htons(port);pin.sin_addr.s_addr=((struct in_addr*)(host->h_addr))->s_addr;int isock;if((isock=socket(AF_INET,SOCK_STREAM,0))==-1){cout<<"open socket error/n"<<endl;exit(1);}string requestHeader;requestHeader="GET "+pagePath+" HTTP/1.1/r/n";requestHeader+="Host: "+hostUrl+"/r/n";requestHeader+="Accept: */*/r/n";requestHeader+="User-Agent: Mozilla/4.0(compatible)/r/n";requestHeader+="connection:Keep-Alive/r/n";requestHeader+="/r/n";if(connect(isock,(const sockaddr*)&pin,sizeof(pin))==-1){cout<<"connect error/n"<<endl;exit(1);}if(send(isock,requestHeader.c_str(),requestHeader.size(),0)==-1){cout<<"send error/n"<<endl;exit(1);}struct timeval timeout={1,0};setsockopt(isock,SOL_SOCKET,SO_RCVTIMEO,(char*)&timeout,sizeof(struct timeval));char c;bool flag=true;while(recv(isock,&c,1,0)>0){if('/r'==c){continue;}else if('/n'==c){if(false==flag)break;flag=false;}else{flag=true;}}int len,BUFFER_SIZE=512;char buffer[BUFFER_SIZE];string pageContent="";while((len=recv(isock,buffer,BUFFER_SIZE-1,0))>0){buffer[len]='/0';pageContent+=buffer;}return pageContent;}int main(int argc, char** argv) {cout<<getPageContent("http://www.hao123.com")<<endl;return 0;}