Function GetVersion

src/utilities/install/install.cpp:407–463

namespace {

USHORT GetVersion(const TEXT* filename, DWORD& verMS, DWORD& verLS, err_handler_t err_handler)
{
/**************************************
 *
 *	G e t V e r s i o n
 *
 **************************************
 *
 * Functional description
 *	Get the file version of a dll whose full path and name is given.
 *	Returns a status value to report a failure, a non-existing file or success.
 *	'version' is only updated in case of success.
 *
 **************************************/

	HANDLE hfile = CreateFile(filename, GENERIC_READ,
		FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_EXISTING, 0, 0);
	if (hfile == INVALID_HANDLE_VALUE)
		return FB_INSTALL_FILE_NOT_FOUND;

	// We'll keep hfile opened until we have read version so that the file
	// can't be deleted between check for existence and version read.

	DWORD dwUnused;
	DWORD rsize = GetFileVersionInfoSize(const_cast<TEXT*>(filename), &dwUnused);
	if (rsize == 0)
	{
		ULONG werr = GetLastError();
		CloseHandle(hfile);
		return (*err_handler) (werr, "GetFileVersionInfoSize()");
	}

	BYTE* hver = new BYTE[rsize];
	if (! GetFileVersionInfo(const_cast<TEXT*>(filename), 0, rsize, hver))
	{
		ULONG werr = GetLastError();
		delete[] hver;
		CloseHandle(hfile);
		return (*err_handler) (werr, "GetFileVersionInfo()");
	}
	CloseHandle(hfile);	// Not needed anymore

	VS_FIXEDFILEINFO* ffi;
	UINT uiUnused;
	if (! VerQueryValue(hver, "\\", (void**)&ffi, &uiUnused))
	{
		ULONG werr = GetLastError();
		delete[] hver;
		return (*err_handler) (werr, "VerQueryValue()");
	}

	verMS = ffi->dwFileVersionMS;
	verLS = ffi->dwFileVersionLS;

	delete[] hver;
	return FB_SUCCESS;
}