postcss-cli

What is postcss-cli?

The postcss-cli package is a command-line interface for PostCSS, a tool for transforming CSS with JavaScript plugins. It allows you to process CSS files using various PostCSS plugins directly from the command line.

What are postcss-cli's main functionalities?

Basic CSS Processing

This command processes the input CSS file (input.css) and outputs the transformed CSS to the specified output file (output.css).

postcss input.css -o output.css

Using Plugins

This command uses the 'autoprefixer' plugin to add vendor prefixes to the CSS rules in the input file and outputs the result to the specified output file.

postcss --use autoprefixer -o output.css input.css

Config File

This command uses a configuration file (postcss.config.js) to specify the plugins and options for processing the CSS file.

postcss -c postcss.config.js -o output.css input.css

Watch Mode

This command watches the input CSS file for changes and automatically processes it whenever it is modified, outputting the result to the specified output file.

postcss input.css -o output.css --watch

Other packages similar to postcss-cli

gulp-postcss

gulp-postcss is a Gulp plugin for PostCSS. It allows you to integrate PostCSS processing into your Gulp build pipeline. Compared to postcss-cli, gulp-postcss is more suitable for complex build processes where you are already using Gulp.

webpack

Webpack is a module bundler that can be configured to use PostCSS through loaders like 'postcss-loader'. It is more powerful and flexible than postcss-cli, making it suitable for larger projects with more complex build requirements.

grunt-postcss

grunt-postcss is a Grunt plugin for PostCSS. It allows you to use PostCSS in your Grunt build tasks. Similar to gulp-postcss, it is more suitable for projects that are already using Grunt for their build process.

README

postcss-cli

Traditional CLI for postcss

Installation

npm install postcss-cli

Usage

postcss [options] [-o output-file|-d output-directory] [input-file]

--output|-o

Output file name. If no output file is specified, postcss will write to stdout, however plugins that rely on output file location will not work properly.

Similarly, if no input file is specified, postcss will read from stdin. Plugins that rely on input file location will not work properly.

--dir|-d

Output files location. Either --output or --dir option, but not both of them, need to be specified. --dir needs to be used if multiple input file is provided.

--use|-u

Plugin to be used. Multiple plugins can be specified. At least one is required.

--config|-c

JSON file with plugin configuration. Plugin names should be the keys.

{
    "autoprefixer": {
        "browsers": "> 5%"
    },
    "postcss-cachify": {
        "baseUrl": "/res"
    }
}

JS configuration can be used if functions are allowed as plugins parameters:

module.exports = {
  "postcss-url": {
    url: function(url) { return "http://example.com/" + url; }
  },
  autoprefixer: {
        browsers: "> 5%"
  }
};

Alternatively configuration options can be passed as --plugin.option parameters.

--safe

Enable Safe Mode, in which PostCSS will try to fix CSS syntax errors.

-h, --help

Show help

Examples

Use autoprefixer as a postcss plugin pass parameters from a json file

postcss --use autoprefixer -c options.json -o screen.css screen.css

Use more than one plugin and pass config parameters

postcss --use autoprefixer --autoprefixer.browsers "> 5%" \
    --use postcss-cachify --postcss-cachify.baseUrl /res \
    -o screen.css screen.css

Use multiple plugins and multiple input files

postcss -u postcss-cachify -u autoprefixer -d build *.css

Licence

MIT

Changelog

1.3.0 / 2015-04-28

• add support for stdin/stdout if no input/output file specified