goodScotchWhiskey to GOOD_SCOTCH_WHISKEY

Yesturday I wrote some PHP snippet to convert camel-style names (e.g. goodScotchWhiskey) to upper-case-style constant names (e.g. GOOD_SCOTCH_WHISKEY).

function _camelToUpper($name)
{
    return strtoupper(join('_', array_slice(
        preg_split('{(?=[A-Z])}s', ucfirst($name)), 1
    )));
}