Clean-css 是一个非常简单的 CSS 压缩程序，基于Node.js环境开发使用，可以删除 CSS 中一些无用的空格、评论以及每个选择器后面的分号，还可以压缩通过@import引入的CSS文件。
环境依赖
Node.js 4.0+ (tested on CentOS, Ubuntu, OS X, and Windows)
npm install clean-css
如何使用命令行
Clean-CSS接受下列命令行参数，使用时请将需要优化的CSS文件<source-file>放置到最后一个参数后面，避免遇到潜在的不可预想的问题。
cleancss [options] source-file, [source-file, ...]
-h, --help output usage information
-v, --version output the version number
-b, --keep-line-breaks Keep line breaks
-c, --compatibility [ie7|ie8] Force compatibility mode (see Readme for advanced examples)
-d, --debug Shows debug information (minification time & compression efficiency)
-o, --output [output-file] Use [output-file] as output instead of STDOUT
-r, --root [root-path] Set a root path to which resolve absolute @import rules
-s, --skip-import Disable @import processing
-t, --timeout [seconds] Per connection timeout when fetching remote @imports (defaults to 5 seconds)
--rounding-precision [n] Rounds to `N` decimal places. Defaults to 2. -1 disables rounding
--s0 Remove all special comments, i.e. /*! comment */
--s1 Remove all special comments but the first one
--semantic-merging Enables unsafe mode by assuming BEM-like semantic stylesheets (warning, this may break your styling!)
--skip-advanced Disable advanced optimizations - ruleset reordering & merging
--skip-aggressive-merging Disable properties merging based on their order
--skip-import-from [rules] Disable @import processing for specified rules
--skip-media-merging Disable @media merging
--skip-rebase Disable URLs rebasing
--skip-restructuring Disable restructuring optimizations
--skip-shorthand-compacting Disable shorthand compacting
--source-map Enables building input's source map
--source-map-inline-sources Enables inlining sources inside source maps
链接: https://fly63.com/nav/1367
