proc urlencode {text} {
    set url ""
    foreach byte [split [encoding convertto utf-8 $text] ""] {
        scan $byte %c i
        if {[string match {[%<>"]} $byte] || $i <= 32 || $i > 127} {
            append url [format %%%02X $i]
        } else {
            append url $byte
        }
    }
    return $url
}