how to query a http request from a vc++ project - c++

Question

I am writing a sample program to get a file from some site.
but it is replying me file not found errors,i dont know how to make an http header.
anyone help me in writing http headers.
AND i am trying to print the ip in this way(printf("%s\n",ptr->ai_addr->sa_data);)
but not getting it how to print ip address??,am i doing it right??
my code is:-
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
// Need to link with Ws2_32.lib, Mswsock.lib, and Advapi32.lib
#pragma comment (lib, "Ws2_32.lib")
#pragma comment (lib, "Mswsock.lib")
#pragma comment (lib, "AdvApi32.lib")
#define DEFAULT_BUFLEN 512
#define DEFAULT_PORT "80"
int __cdecl main(int argc, char **argv)
{
WSADATA wsaData;
SOCKET ConnectSocket = INVALID_SOCKET;
struct addrinfo *result = NULL,
*ptr = NULL,
hints;
char *sendbuf = "GET / HTTP/1.1[CRLF] Host: www.espncricinfo.com[CRLF]Connection: close[CRLF]User-Agent: Web-sniffer/1.0.37 (+http://web-sniffer.net/)[CRLF]Accept-Encoding: gzip[CRLF]Accept-Charset: ISO-8859-1,UTF-8;q=0.7,*;q=0.7[CRLF]Cache-Control: no-cache[CRLF]Accept-Language: de,en;q=0.7,en-us;q=0.3 \r\n";
char buff[DEFAULT_BUFLEN],recvbuf[512];
int iResult;
int recvbuflen = DEFAULT_BUFLEN;
// Validate the parameters
if (argc != 1) {
printf("usage: %s server-name\n", argv[0]);
return 1;
}
// Initialize Winsock
iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
if (iResult != 0) {
printf("WSAStartup failed with error: %d\n", iResult);
return 1;
}
ZeroMemory( &hints, sizeof(hints) );
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
// Resolve the server address and port
iResult = getaddrinfo("122.169.255.9",DEFAULT_PORT, &hints, &result);
if ( iResult != 0 ) {
printf("getaddrinfo failed with error: %d\n", iResult);
WSACleanup();
return 1;
}
// Attempt to connect to an address until one succeeds
for(ptr=result; ptr != NULL ;ptr=ptr->ai_next) {
// Create a SOCKET for connecting to server
ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype,
ptr->ai_protocol);
printf("inside loop %s ",ptr->ai_addr->sa_data);
if (ConnectSocket == INVALID_SOCKET) {
printf("socket failed with error: %ld\n", WSAGetLastError());
WSACleanup();
return 1;
}
// Connect to server.
iResult = connect(ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
printf("%d\n",ptr->ai_addrlen);
// printf("%s\n",ptr->ai_addr->sa_family);
printf("%s\n",ptr->ai_addr->sa_data);
if (iResult == SOCKET_ERROR) {
printf("socket error\n");
printf("failed with error: %d\n", WSAGetLastError());
closesocket(ConnectSocket);
ConnectSocket = INVALID_SOCKET;
continue;
}
break;
}
freeaddrinfo(result);
if (ConnectSocket == INVALID_SOCKET) {
printf("Unable to connect to server!\n");
WSACleanup();
return 1;
}
// Send an initial buffer
char filepath[]="pakistan/content/current/story/517271.html";
sprintf(buff,"GET %s\r\n",filepath);
iResult = send( ConnectSocket,buff, (int)strlen(buff), 0 );
if (iResult == SOCKET_ERROR)
{
printf("send failed with error: %d\n", WSAGetLastError());
closesocket(ConnectSocket);
WSACleanup();
return 1;
}
printf("Bytes Sent: %ld\n", iResult);
// shutdown the connection since no more data will be sent
iResult = shutdown(ConnectSocket, SD_SEND);
if (iResult == SOCKET_ERROR) {
printf("shutdown failed with error: %d\n", WSAGetLastError());
closesocket(ConnectSocket);
WSACleanup();
return 1;
}
do
{
iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
//if ( iResult > 0 ) printf("Bytes received: %d\n", iResult);
if ( iResult > 0 )
{
printf("Bytes received: %d\n", iResult);
printf("%s",recvbuf);
}
else if ( iResult == 0 )
printf("Connection closed\n");
else
printf("recv failed with error: %d\n", WSAGetLastError());
} while( iResult>0 );
// cleanup
closesocket(ConnectSocket);
WSACleanup();
return 0;
}

Answer 1

If you're getting "File Not Found", it's because you're requesting a file that can't be found.
Perhaps try "/pakistan/content/current/story/517271.html", with the leading slash.
And where's your HTTP protocol specifier?
Write:
GET path HTTP/1.0
(1.0 because you probably don't want to mess about with virtual hosts; 1.1 if you have to)
And why do you shutdown the socket before attempting to read from it...? I know you only shutdown the "send" pipe, but it still seems odd.
Perhaps you ought to use a pre-established library to do this for you.
The webserver at http://122.169.255.9/ doesn't appear to actually work. Perhaps test with a known-good server like http://www.google.com first.

Answer 2

If you're going to use Microsoft Windows functions, the HTTP functions in WinInet are a lot easier. See HttpOpenRequest/HttpSendRequest/HttpQueryInfo/InternetReadFile

Answer 3

If you don't want to reinvent the wheel, use a library like libcurl.

Answer 4

In addition to Tomalak Geret'kal
You'll want to use HTTP/1.0 unless you want to check for chunked content and more stuff HTTP 1.1 can throw at you.
Install Wireshark and log the requests. You'll see what is wrong.
I'm not aware of [CRLF] being automatically changed to \r\n