作用:可以對javascript的大小進行壓縮。使javascript的載入速度變快。
用法:
在 cmd下面輸入的東西;
cscript ESC.wsf -l 3 -ow ../global.js global.js
上面是一個簡單的例子:可以自己建一個bat檔案放在目前的目錄下面
cscript ESC.wsf -l 壓縮層級 -ow 。。/要壓縮到那個目錄 需要進行壓縮的原js
1.
Level 0 :: No compression //沒有處裡
Level 1 :: Comment removal //刪除掉注釋
Level 3 :: Newline removal //刪除掉新行
Level 4 :: Variable substitution //變數的替換
2.時所用到的參數:
-l 層級
-s
-v
-$
-oa 以追加的形式覆蓋
-ow 以覆蓋的形式覆蓋
所用壓縮包在附件 還有協助文檔
使用的例子見壓縮包中的圖片。
http://xiazai.jb51.net/201003/yuanma/ESC.rar
Introduction
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