一、下载安装 atom-less
atom-less 项目在这里：https://github.com/schmuli/atom-less
安装方法请参考这篇博文：http://blog.csdn.net/kingittiger/article/details/51881442
二、使用方法
atom-less 的使用略显奇葩。跟其它 LESS 插件不同，它需要在每个 less 文件的头部都写上配置行，编译器读取这行配置，才可以正常运作。好处是，不同的 less 就可以用不同的配置，做到灵活输出，不用频繁去设置全局参数。
1. 官方参考说明 README.md
# atom-less package An Atom package that auto-compiles LESS files on save, with support for LESS plugins, Clean-CSS and AutoPrefixer. ### Configuration On the first line of LESS files, add a valid JSON comment, not including the outer brackets (‘{‘ and ‘}‘), with the following properties: - **"main"**: `string` - The relative or absolute path to the main LESS file to be compiled (ignores all other options) - **"out"**: `boolean|string` - `true` to output using the filename, or a string specifying a name to use - **"compress"**: `boolean` - Use Less.JS built-in compression (not compatible with Clean-CSS or Source Maps) - **"strictMath"**: `boolean` - Require brackets around math expressions - **"sourceMap"**: `boolean|Object` - `true` to turn on source maps, or an object specifying LESS source map properties - **"cleancss"**: `string|object` - a string specifying the ‘compatibility‘ property, or an object specifying the Clean-CSS properties (not compatible with Source Maps) - **"autoprefixer"**: `string|object` - a `;` separated string specifying the ‘browsers‘ property, or an object specifying the AutoPrefixer properties Other LESS compiler options might work but are untested at this point. ### Road Map 1. Remove dependency on inline comments, and instead use a .lesscfg project file, allowing easier configuration and automatic support of additional LESS plugins 2. Change callback passing to use Promises
来源：https://atom.io/packages/atom-less
2. 常用选项配置
其实常用的选项就两个：out 和 compress。out 配置输出，compress 配置是否压缩。配置要写成 JSON 注释形式，但不包含花括号 { }。
配置形式：
// "<选项1>": "<配置1>", "<选项2>": "<配置2>", ...
下面举几个例子：
// "out": true ## 输出同名的 css 文件，不压缩
// "out": "test.css" ## 输出名为 test.css 文件，不压缩
// "out": true, "compress": true ## 输出名为 test.css 文件，压缩
3. 常见问题问答
valid less comment错误：https://github.com/schmuli/atom-less/issues/4
