Different result everytime it is called - c

Question

Why is it that the following code does not print the same value each time it is run?
Is there something that I overlooked? Thanks.
#include <windows.h>
#include <stdio.h>
#include <winhttp.h>
#pragma comment (lib, "winhttp")
int main(void)
{
DWORD dwSize = 0;
DWORD dwDownloaded = 0;
LPSTR pszOutBuffer;
BOOL bResults = FALSE;
HINTERNET hSession = NULL,
hConnect = NULL,
hRequest = NULL;
// Use WinHttpOpen to obtain a session handle.
hSession = WinHttpOpen( L"WinHTTP Example/1.0", WINHTTP_ACCESS_TYPE_NO_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0 );
// Specify an HTTP server.
if( hSession )
hConnect = WinHttpConnect( hSession, L"www.htc.com",
INTERNET_DEFAULT_HTTP_PORT, 0 );
// Create an HTTP request handle.
if( hConnect )
hRequest = WinHttpOpenRequest( hConnect, L"GET", L"uploadedImages/Common/Shared_Image/Icons/HTC_HD2_Location.jpg",
NULL, WINHTTP_NO_REFERER,
WINHTTP_DEFAULT_ACCEPT_TYPES,
0 );
// Send a request.
if( hRequest )
bResults = WinHttpSendRequest( hRequest,
WINHTTP_NO_ADDITIONAL_HEADERS, 0,
WINHTTP_NO_REQUEST_DATA, 0,
0, 0 );
// End the request.
if( bResults )
bResults = WinHttpReceiveResponse( hRequest, NULL );
// Keep checking for data until there is nothing left.
if( bResults )
{
do
{
// Check for available data.
dwSize = 0;
if( !WinHttpQueryDataAvailable( hRequest, &dwSize ) )
printf( "Error %u in WinHttpQueryDataAvailable.\n",
GetLastError( ) );
// Allocate space for the buffer.
pszOutBuffer = new char[dwSize+1];
if( !pszOutBuffer )
{
printf( "Out of memory\n" );
dwSize=0;
}
else
{
// Read the data.
ZeroMemory( pszOutBuffer, dwSize+1 );
if( !WinHttpReadData( hRequest, (LPVOID)pszOutBuffer,
dwSize, &dwDownloaded ) )
printf( "Error %u in WinHttpReadData.\n", GetLastError( ) );
else
printf( "%s", pszOutBuffer );
// Free the memory allocated to the buffer.
delete [] pszOutBuffer;
}
} while( dwSize > 0 );
}
// Report any errors.
if( !bResults )
printf( "Error %d has occurred.\n", GetLastError( ) );
// Close any open handles.
if( hRequest ) WinHttpCloseHandle( hRequest );
if( hConnect ) WinHttpCloseHandle( hConnect );
if( hSession ) WinHttpCloseHandle( hSession );
return 0;
}

Answer 1

You are printing the content of a .jpg file as a C string. It isn't a string, it won't be zero-terminated correctly. You'll get some kind of rendition of the bytes in the .jpg, followed by a random number of characters. Until it blunders into a zero somewhere. Apparently quickly enough to prevent your program crashing.