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Language: C++
Expertise: Intermediate

Jun 17, 2008

Sometimes people assume that the default web browser is the program that is registered in the Windows registry to open files with an .html extension. However, it's possible to set a default program to open .html files and another to open URL links that use the HTTP protocol.

The code below determines the default web browser for the HTTP protocol:

DWORD size = 256; HKEY hKey; int i, pos, len;
TCHAR browserProgram[512], TCHAR buf[256];
TCHAR *exeExtension = ".exe"; 
RegOpenKeyEx(HKEY_CLASSES_ROOT, _TEXT("http\\shell\\open\\command"), 
 0, KEY_QUERY_VALUE, &hKey);
RegQueryValueEx(hKey, NULL, NULL, NULL, (LPBYTE)buf, &size);
RegCloseKey(hKey); 
if (buf[0] == _TEXT('\"'))
 lstrcpy(browserProgram, &buf[1]);
else
 lstrcpy(browserProgram, buf);
len = lstrlen(browserProgram);
pos = len - 4;
for (i = 0; i < len - 3; i++)
 if (!strnicmp(&browserProgram[i], exeExtension, 4))
 {
  pos = i; break;
 }
browserProgram[pos + 4] = _TEXT('\0');
std::cout << browserProgram << std::endl;