作用：可以对javascript的大小进行压缩。使javascript的加载速度变快。
用法：
在 cmd下面输入的东西；
cscript ESC.wsf -l 3 -ow ../global.js global.js
上面是一个简单的例子：可以自己建一个bat文件放在当前目录下面
cscript ESC.wsf -l 压缩级别 -ow 。。/要压缩到那个目录 需要进行压缩的原js
1.
Level 0 :: No compression //没有处里
Level 1 :: Comment removal //删除掉注释
Level 3 :: Newline removal //删除掉新行
Level 4 :: Variable substitution //变量的替换
2.下图时所用到的参数：
-l 级别
-s
-v
-$
-oa 以追加的形式覆盖
-ow 以覆盖的形式覆盖
所用压缩包在附件 还有帮助文档
使用的例子见压缩包中的图片。
下载地址
http://xiazai.jb51.net/201003/yuanma/ESC.rarIntroduction
ESC is an ECMAScript pre-processor written in JScript, enabling an unlimited number of external scripts to be compressed/crunched into supertight, bandwidth-optimized packages. Featuring several compression-techniques such as comment removal, whitespace stripping, newline stripping and variable substitution ESC can reduce the overall size of your code with up to ~45%. Single, multiple scripts and even directories with scripts can be merged together at the compression level you decide. The processed output can later be appended or written to a file, or piped to another application for further processing via STDOUT. ESC do NOT support crunching of inline scripts. So any attempt passing HTML, ASP, JSP, PHP or other equivalent documents to ESC is done at your own risk. ESC supports four levels of compression, where a higher level equals higher compression. Beware though that levels >2 requires your code to be syntaxically perfect or ESC will punish you by producing a broken and useless output. The compression ratio should hit around 25% using the default compression level on a vanilla looking script, but results as high as ~45% can be achieved depending on the script's design / your style of writing code. ESC's compression engine is intelligent in the meaning that it has language syntax, statement and keyword awareness and it *knows* about native objects and members provided by the most common scripting hosts. This knowledgebase can easily be extended by pluggin in userdefined maps with additional information to further gain control of the crunching procedure. During processing following things are taken into account : String and RegExpression read-ahead
JScript Conditional compilation statements and variables
ECMA-262 Core language definitions (ECMAScript)
Intermediate DOM's (level 0) and DOM level 1
MS JScript specific objects/methods
Netscape/Mozilla/Opera specific objects/methods/properties
MS WSH (Windows Scripting Host) 1+ native objects
