PostCSS CLI

Install

npm i -g|-D postcss-cli

Usage

postcss [input.css] [OPTIONS] [-o|--output output.css] [-w|--watch]

The input may also be a glob:

postcss src/*.css [OPTIONS]

Recursively read a directory:

postcss src/**/*.css [OPTIONS]

⚠️ If there are multiple input files, the --dir or --replace option must be passed.

cat input.css | postcss [OPTIONS] > output.css

⚠️ If no input files are passed, it reads from stdin. If neither -o, --dir, or --replace is passed, it writes to stdout.

Options

Name	Type	Default	Description
-d, --dir	{String}	undefined	Output Directory
-b, --base	{String}	undefined	Use together with --dir for keeping directory structure.
-x, --ext	{String}	extname(output)	Output File Extension
-o, --output	{String}	undefined	Output File
-r, --replace	{String}	undefined	Replace Input <=> Output
-p, --parser	{String}	undefined	Custom PostCSS Parser
-s, --syntax	{String}	undefined	Custom PostCSS Syntax
-t, --stringifier	{String}	undefined	Custom PostCSS Stringifier
-w, --watch	{Boolean}	false	Enable Watch Mode
--poll	{Number}	100	Use polling for file watching. Default 100 milliseconds
-u, --use	{Array}	[]	PostCSS Plugins
-m, --map	{Boolean}	{ inline: true }	External Sourcemaps
--no-map	{Boolean}	false	Disable Sourcemaps
-e, --env	{String}	process.env.NODE_ENV	Sets $NODE_ENV
-c, --config	{String}	dirname(file)	PostCSS Config Path postcss.config.js
-h, --help	{Boolean}	false	CLI Help
-v, --version	{Boolean}	false	CLI Version

ℹ️ More details on custom parsers, stringifiers and syntaxes, can be found here.

Config

If you need to pass options to your plugins, or have a long plugin chain, you'll want to use a configuration file.

postcss.config.js

module.exports = {
  parser: 'sugarss',
  plugins: [
    require('postcss-import')({...options}),
    require('postcss-url')({ url: 'copy', useHash: true })
  ]
}

Note that you can not set the from or to options for postcss in the config file. They are set automatically based on the CLI arguments.

Context

For more advanced usage it's recommend to to use a function in postcss.config.js, this gives you access to the CLI context to dynamically apply options and plugins per file

Name	Type	Default	Description
env	{String}	'development'	process.env.NODE_ENV
file	{Object}	dirname, basename, extname	File
options	{Object}	map, parser, syntax, stringifier	PostCSS Options

postcss.config.js

module.exports = (ctx) => ({
  map: ctx.options.map,
  parser: ctx.file.extname === '.sss' ? 'sugarss' : false,
  plugins: {
    'postcss-import': { root: ctx.file.dirname }),
    'cssnano': ctx.env === 'production' ? {} : false
  }
})

⚠️ If you want to set options via CLI, it's mandatory to reference ctx.options in postcss.config.js

postcss input.sss -p sugarss -o output.css -m

postcss.config.js

module.exports = (ctx) => ({
  map: ctx.options.map,
  parser: ctx.options.parser,
  plugins: {
    'postcss-import': { root: ctx.file.dirname },
    'cssnano': ctx.env === 'production' ? {} : false
  }
})