Hi
How can I read text from a webpage asynchronously,from within C++. After you first connect to the internet using usual means, you enter the string
e.g. "http://www.bbc.co.uk/test/run.txt" and the C++ program reads the information: "<title>BBC Website</title><body>This is the BBC website...." from the internet.
Here I want to connect to website every 60 minutes and fetch only first 100 lines of the run.txt file as mentioned above. How can I do this using C++ and asynchronous winsock ???
Code done so far is given below...please help me
Code:
#define WIN_OS
#define _DEBUG_PRINT(X) /* X */
//For commn
#include <iostream>
#include <string>
#include <stdlib.h>
#include <assert.h>
#ifdef WIN_OS
#include <Winsock2.h>
#endif
#define SEND_RQ(MSG) \
/*cout<<send_str;*/ \
send(sock,MSG,strlen(MSG),0);
using namespace std;
//<exe> hostname api parameters
int request (char* hostname, char* api, char* parameters, string& message)
{
#ifdef WIN_OS
{
WSADATA WsaData;
WSAStartup (0x0101, &WsaData);
}
#endif
sockaddr_in sin;
int sock = socket (AF_INET, SOCK_STREAM, 0);
if (sock == -1) {
return -100;
}
sin.sin_family = AF_INET;
sin.sin_port = htons( (unsigned short)80);
struct hostent * host_addr = gethostbyname(hostname);
if(host_addr==NULL) {
_DEBUG_PRINT( cout<<"Unable to locate host"<<endl );
return -103;
}
sin.sin_addr.s_addr = *((int*)*host_addr->h_addr_list) ;
_DEBUG_PRINT( cout<<"Port :"<<sin.sin_port<<", Address : "<< sin.sin_addr.s_addr<<endl);
if( connect (sock,(const struct sockaddr *)&sin, sizeof(sockaddr_in) ) == -1 ) {
_DEBUG_PRINT( cout<<"connect failed"<<endl ) ;
return -101;
}
string send_str;
SEND_RQ("POST ");
SEND_RQ(api);
SEND_RQ(" HTTP/1.0\r\n");
SEND_RQ("Accept: */*\r\n");
SEND_RQ("User-Agent: Mozilla/4.0\r\n");
char content_header[100];
sprintf(content_header,"Content-Length: %d\r\n",strlen(parameters));
SEND_RQ(content_header);
SEND_RQ("Accept-Language: en-us\r\n");
SEND_RQ("Accept-Encoding: gzip, deflate\r\n");
SEND_RQ("Host: ");
SEND_RQ("hostname");
SEND_RQ("\r\n");
SEND_RQ("Content-Type: application/x-www-form-urlencoded\r\n");
//If you need to send a basic authorization
//string Auth = "username:password";
//Figureout a way to encode test into base64 !
//string AuthInfo = base64_encode(reinterpret_cast<const unsigned char*>(Auth.c_str()),Auth.length());
//string sPassReq = "Authorization: Basic " + AuthInfo;
//SEND_RQ(sPassReq.c_str());
SEND_RQ("\r\n");
SEND_RQ("\r\n");
SEND_RQ(parameters);
SEND_RQ("\r\n");
_DEBUG_PRINT(cout<<"####HEADER####"<<endl);
char c1[1];
int l,line_length;
bool loop = true;
bool bHeader = false;
while(loop) {
l = recv(sock, c1, 1, 0);
if(l<0) loop = false;
if(c1[0]=='\n') {
if(line_length == 0) loop = false;
line_length = 0;
if(message.find("200") != string::npos)
bHeader = true;
}
else if(c1[0]!='\r') line_length++;
_DEBUG_PRINT( cout<<c1[0]);
message += c1[0];
}
message="";
if(bHeader) {
_DEBUG_PRINT( cout<<"####BODY####"<<endl) ;
char p[1024];
while((l = recv(sock,p,1023,0)) > 0) {
_DEBUG_PRINT( cout.write(p,l)) ;
p[l] = '\0';
message += p;
}
_DEBUG_PRINT( cout << message.c_str());
} else {
return -102;
}
#ifdef WIN_OS
WSACleanup( );
#endif
return 0;
}
int main(){
string message;
int request ("www.somesite.com", "/post_url.pl", "search=hello&date=todat", string& message);
// message contains response!
}