Usage:
  postcss [input.css] [OPTIONS] [-o|--output output.css] [--watch|-w]
  postcss <input.css>... [OPTIONS] --dir <output-directory> [--watch|-w]
  postcss <input-directory> [OPTIONS] --dir <output-directory> [--watch|-w]
  postcss <input-glob-pattern> [OPTIONS] --dir <output-directory> [--watch|-w]
  postcss <input.css>... [OPTIONS] --replace

Basic options:
  -o, --output   Output file                                            [string]
  -d, --dir      Output directory                                       [string]
  -r, --replace  Replace (overwrite) the input file                    [boolean]
  -m, --map      Create an external sourcemap
  --no-map       Disable the default inline sourcemaps
  -w, --watch    Watch files for changes and recompile as needed       [boolean]
  --verbose      Be verbose                                            [boolean]
  --env          A shortcut for setting NODE_ENV                        [string]

Options for use without a config file:
  -u, --use      List of postcss plugins to use                          [array]
  --parser       Custom postcss parser                                  [string]
  --stringifier  Custom postcss stringifier                             [string]
  --syntax       Custom postcss syntax                                  [string]

Options for use with --dir:
  --ext   Override the output file extension; for use with --dir        [string]
  --base  Mirror the directory structure relative to this path in the output
          directory, for use with --dir                                 [string]

Advanced options:
  --include-dotfiles  Enable glob to match files/dirs that begin with "."
                                                                       [boolean]
  --poll              Use polling for file watching. Can optionally pass polling
                      interval; default 100 ms
  --config            Set a custom directory to look for a config file  [string]

Options:
  --version   Show version number                                      [boolean]
  -h, --help  Show help                                                [boolean]

Examples:
  postcss input.css -o output.css                       Basic usage
  postcss src/**/*.css --base src --dir build           Glob Pattern & output
  cat input.css | postcss -u autoprefixer > output.css  Piping input & output

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

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

Input files may contain globs (e.g. src/**/*.css). If you pass an input
directory, it will process all files in the directory and any subdirectories,
respecting the glob pattern.