gebase/lib/url.awk

function url_decode( str ) {
    for ( y = 0; y < 127; y++ ) {
        if ( y != 37 ) {
            gsub( \
                sprintf( "%%%02x|%%%02X", y, y ), \
                y == 38 \
                    ? "\\&" \
                    : sprintf("%c", y), \
                str \
            );
        }
        gsub( /%25/, "%", str );
    }
    return str;
}