function urlencode() {    # just workaround
    local s=$1
    s=${s// /+}
    echo "${s//
/%0A}"
}

function http_post() {
    local host=$1
    local path=$2
    local post_data=$3
    local LANG=C

    exec 3<> "/dev/tcp/$host/80"

    (
    echo -e "POST $path HTTP/1.0\r"
    echo -e "Host: $host\r"
    echo -e "Content-Length: ${#post_data}\r"
    echo -e 'Content-Type: application/x-www-form-urlencoded; charset=utf-8\r'
    echo -e '\r'
    echo "$post_data"
    ) >&3

    local s
    read -d '' s <&3
    echo "$s"

    exec 3>&-
    exec 3<&-
}

function trackback() {
    local host=$1
    local path=$2
    local title=$(urlencode "$3")
    local url=$4
    local blog_name=$(urlencode "$5")

    local excerpt
    read -d '' excerpt
    excerpt=$(urlencode "$excerpt")

    http_post "$host" "$path" \
      "title=$title&url=$url&blog_name=$blog_name&excerpt=$excerpt"
}

trackback 'll.jus.or.jp' '/2008/blog/archives/38/trackback' \
  'LL Future参加' 'http://ja.doukaku.org/207/' 'LL Future Hole 9' <<'__EOT__'
LL Futureに行ってきました！
楽しかった！ 自分の回答がスクリーンに出た＞＜
__EOT__