jjencode、jjdecode

記号だけで任意のJavaScriptコードを実行できるようにするフィルタプログラムと、それを元のコードに戻すデコーダプログラム。ppencodeのような物。
特長:

• 日本語(UTF-8)に対応している
• 使用するグローバル変数が$_だけ
• クロスブラウザ

実用的ですね。

alert("おはよう、世界！");

が

$_={_:+[],__:+[]};$_.__++;$_.___=$_.__+$_.__;$_.____=$_.___+$_.__;$_._____=$_.___<<$_.__;$_.______=$_.___*$_.___+$_.__;$_._______=$_.___*$_.____;$_.________=$_._____+$_.____;$_._________=$_.___<<$_.___;$_.__________=$_.____*$_.____;$_.$$=""+{};$_.$_=""+[][[]];$_.$=$_.$$[$_.______];$_.$+=$_.$$[$_.__];$_.$+=$_.$_[$_.__];$_.$+=(''+!$_)[$_.____];$_.$+=(''+!'')[$_._];$_.$+=(''+!'')[$_.__];$_.$+=$_.$_[$_._];$_.$+=$_.$$[$_.______];$_.$+=(''+!'')[$_._];$_.$+=$_.$$[$_.__];$_.$+=(''+!'')[$_.__];$_._$_=(''+!$_)[$_.__];$_._$__=$_.$$[$_.___];$_._$___=$_.$$[$_.______];$_._$____=$_.$_[$_.___];$_._$_____=$_.$$[$_._____];$_._$______=$_.$_[$_._____];$_.$$_=(''+!'')[$_.__]+$_._$_____+(''+!'')[$_._]+$_.$_[$_._]+(''+!'')[$_.__]+$_.$_[$_.__];$_.$$$=$_[$_.$][$_.$];$_.$$$($_.$$$($_.$$_+'"'+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_._______+$_.__)+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_._______+$_._$___)+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_._______+$_.______)+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_.________+$_.___)+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_.________+$_._____)+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_.___+$_._________)+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_.___+$_.___)+'\\'+$_.$_[$_._]+(''+$_.____+$_._+$_._____+$_._$_)+'\\'+$_.$_[$_._]+(''+$_.____+$_._+$_._______+$_._$______)+'\\'+$_.$_[$_._]+(''+$_.____+$_._+$_._________+$_._________)+'\\'+$_.$_[$_._]+(''+$_.____+$_._+$_._____+$_._______)+'\\'+$_.$_[$_._]+(''+$_.____+$_._+$_._+$_.__)+'\\'+$_.$_[$_._]+(''+$_._____+$_._$_____+$_.__+$_._______)+'\\'+$_.$_[$_._]+(''+$_.________+$_.______+$_._____+$_._$___)+'\\'+$_.$_[$_._]+(''+$_._$______+$_._$______+$_._+$_.__)+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_.___+$_.___)+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_.___+$_.__________)+'\\'+$_.$_[$_._]+(''+$_._+$_._+$_.____+$_._$__)+'"')())();

になる。

jjencode.rb

#!/usr/bin/env ruby

header = (<<'.'
$_={_:+[],__:+[]}; // グローバル変数$_を定義、$_._は0
$_.__++; // $_._は0、$_.__は1
$_.___=$_.__+$_.__; // $_.___は2
$_.____=$_.___+$_.__; // $_.____は3
$_._____=$_.___<<$_.__; // $_._____は4
$_.______=$_.___*$_.___+$_.__; // $_.______は5
$_._______=$_.___*$_.____; // $_._______は6
$_.________=$_._____+$_.____; // $_.________は7
$_._________=$_.___<<$_.___; // $_._________は8
$_.__________=$_.____*$_.____; // $_.__________は9
$_.$$=""+{}; // $_.$$は"[object Object]"
$_.$_=""+[][[]]; // $_.$_は"undefined"
$_.$=$_.$$[$_.______]; // $_.$は"c"
$_.$+=$_.$$[$_.__]; // $_.$は"co"
$_.$+=$_.$_[$_.__]; // $_.$は"con"
$_.$+=(''+!$_)[$_.____]; // $_.$は"cons"、"false"[3]=="s"
$_.$+=(''+!'')[$_._]; // $_.$は"const"
$_.$+=(''+!'')[$_.__]; // $_.$は"constr"
$_.$+=$_.$_[$_._]; // $_.$は"constru"
$_.$+=$_.$$[$_.______]; // $_.$は"construc"
$_.$+=(''+!'')[$_._]; // $_.$は"construct"
$_.$+=$_.$$[$_.__]; // $_.$は"constructor"
$_.$+=(''+!'')[$_.__]; // $_.$は"constrtor"
$_._$_=(''+!$_)[$_.__]; // $_._$_=="a"
$_._$__=$_.$$[$_.___]; // $_._$__ = "b"
$_._$___=$_.$$[$_.______]; // $_._$___は"c"
$_._$____=$_.$_[$_.___]; // $_._$____=="d"
$_._$_____=$_.$$[$_._____]; // $_.$_____=="e"
$_._$______=$_.$_[$_._____]; // $_.______=="f"
$_.$$_=(''+!'')[$_.__]+$_._$_____+(''+!'')[$_._]+$_.$_[$_._]+(''+!'')[$_.__]+$_.$_[$_.__]; // $_.$$_="return"
$_.$$$=$_[$_.$][$_.$]; // $_.$$$==Function
.
).gsub(%r!\s*//.*|\n!, '') # コメントと改行を削除する

def num2code(n)
  code = sprintf("%04x", n).split(//).map{|s|
    i = "abcdef".index(s)
    if i
      "$_._$#{ '_' * i.succ }"
    else
      "$_.#{ '_' * s.to_i.succ }"
    end
  }.join('+')
  "(''+#{ code })"
end

code = $stdin.read

main =<<"."
$_.$$$($_.$$$($_.$$_+'"'+#{
code.unpack('U*').map{|n| "'\\\\'+$_.$_[$_._]+" + num2code(n) }.join('+')
}+'"')())();
.

result = header + main

puts result

jjdecode.js

Object.constructor = function (code) {
  alert(Function(code)());
};

// ここに記号化されたプログラムを貼る