isValidWindowsFilename function
Checks if the filename is a valid Windows filename.
This includes checking for illegal characters, reserved file names, null characters, and length.
Implementation
bool isValidWindowsFilename(String filename) {
return isLegalLength(filename) &&
!containsIllegalWindowsCharacters(filename) &&
!isReservedWindowsFilename(filename) &&
!containsNullCharacter(filename) &&
!isRelativePath(filename);
}