docopt creates beautiful command-line interfaces

.. image:: https://travis-ci.org/docopt/docopt.php.svg?branch=master :target: https://travis-ci.org/docopt/docopt.php

This is a straight PHP transliteration of Vladimir Keleshev's brilliant docopt <https://github.com/docopt/docopt/>_ Python library. There are a few artefacts in the code as a result that may seem inefficient and non-idiomatic to PHP, this has been done to make integrating changes more efficient.

As a result, unless a bug is present only in the PHP version, pull requests are unlikely to be accepted unless they are themselves direct transliterations of bugfixes in the Python version.

This port has been marked version 1.0. It is based on the Python version at commit a093f938b7f26564434f3c15a1dcc39e017ad638 <https://github.com/docopt/docopt/commit/a093f938b7f26564434f3c15a1dcc39e017ad638>_ (labelled 0.6.2).

It has been quite stable for a long time and has barely been changed. The Python version receives only occasional bugfixes and keeping the version numbers pinned has been more trouble than it has been worth.

There are also some major backward compatibility breaks. Rather than dwell in 0.x semver hell, the PHP port will liberally bump major numbers henceforth when BC breaks regardless of the reason.

• The PHP API has changed slightly. Docopt\docopt() has been renamed to Docopt::handle() to fix autoloader support. See issue #3 <https://github.com/docopt/docopt.php/pull/3>_.

• Docopt.py also has a significant BC break. Existing users should read the information below about Usage and Option sections. See issue 102 <https://github.com/docopt/docopt/issues/102>_ for more info.

Please see the Python version's README <https://github.com/docopt/docopt/blob/master/README.rst>_ for details of any new and breaking changes that are not specific to the PHP version.

There is also at least one significant known issue with the upstream Python version. Due to the porting strategy used for the PHP version, it inherits the bug surface of the Python version (and if it doesn't, that's actually a bug!):

• Issues with multi-word argument and option values (PHP report <https://github.com/docopt/docopt.php/issues/21>, Upstream report <https://github.com/docopt/docopt/issues/207>)

---

Isn't it awesome how optparse and argparse generate help messages based on your code?!

Hell no! You know what's awesome? It's when the option parser is generated based on the beautiful help message that you write yourself! This way you don't need to write this stupid repeatable parser-code, and instead can write only the help message--the way you want it.

docopt helps you create most beautiful command-line interfaces easily:

.. code:: php

<?php
$doc = <<<DOC
Naval Fate.

Usage:
  naval_fate.php ship new <name>...
  naval_fate.php ship <name> move <x> <y> [--speed=<kn>]
  naval_fate.php ship shoot <x> <y>
  naval_fate.php mine (set|remove) <x> <y> [--moored | --drifting]
  naval_fate.php (-h | --help)
  naval_fate.php --version

Options:
  -h --help     Show this screen.
  --version     Show version.
  --speed=<kn>  Speed in knots [default: 10].
  --moored      Moored (anchored) mine.
  --drifting    Drifting mine.

DOC;

require('path/to/src/docopt.php');
$args = Docopt::handle($doc, array('version'=>'Naval Fate 2.0'));
foreach ($args as $k=>$v)
    echo $k.': '.json_encode($v).PHP_EOL;

Beat that! The option parser is generated based on the docstring above that is passed to docopt function. docopt parses the usage pattern ("Usage: ...") and option descriptions (lines starting with dash "-") and ensures that the program invocation matches the usage pattern; it parses options, arguments and commands based on that. The basic idea is that a good help message has all necessary information in it to make a parser.

Installation

Install docopt.php using Composer <http://getcomposer.org>_::

composer require docopt/docopt

Alternatively, you can just drop docopt.php file into your project--it is self-contained. Get source on github <http://github.com/docopt/docopt.php>_.

docopt.php is tested with PHP 7; it should still work with PHP 5.3+ but this support will become increasingly fragile and will at some point cease to be supported at all. You should update to 7 as soon as you can.

Testing

Configure your repo for running tests::

./dev-setup

You can run unit tests with the following command::

php test.php

This will run the Python language agnostic tests as well as the PHP docopt tests.

API

.. code:: php

<?php
require('/path/to/src/docopt.php');

// short form, simple API
$args = Docopt::handle($doc);

// short form (5.4 or better)
$args = (new \Docopt\Handler)->handle($sdoc);

// long form, simple API (equivalent to short)
$params = array(
    'argv'=>array_slice($_SERVER['argv'], 1),
    'help'=>true,
    'version'=>null,
    'optionsFirst'=>false,
);
$args = Docopt::handle($doc, $params);

// long form, full API
$handler = new \Docopt\Handler(array(
    'help'=>true,
    'optionsFirst'=>false,
));
$handler->handle($doc, $argv);

Docopt::handle() takes 1 required and 1 optional argument:

• doc is a string that contains a help message that will be parsed to create the option parser. The simple rules of how to write such a help message are given in next sections. Here is a quick example of such a string:

.. code:: php

<?php
$doc = <<<DOC
Usage: my_program.php [-hso FILE] [--quiet | --verbose] [INPUT ...]

Options:
  -h --help    show this
  -s --sorted  sorted output
  -o FILE      specify output file [default: ./test.txt]
  --quiet      print less text
  --verbose    print more text

DOC;

• params is an optional array of additional data to influence docopt. The following keys are supported:

  • argv is an optional argument vector; by default docopt uses the argument vector passed to your program ($_SERVER['argv']). Alternatively you can supply a list of strings like array('--verbose', '-o', 'hai.txt').

  • help, by default true, specifies whether the parser should automatically print the help message (supplied as doc) and terminate, in case -h or --help option is encountered (options should exist in usage pattern, more on that below). If you want to handle -h or --help options manually (as other options), set help to false.

  • version, by default null, is an optional argument that specifies the version of your program. If supplied, then, (assuming --version option is mentioned in usage pattern) when parser encounters the --version option, it will print the supplied version and terminate. version could be any printable object, but most likely a string, e.g. "2.1.0rc1".

    Note, when docopt is set to automatically handle -h, --help and --version options, you still need to mention them in usage pattern for this to work. Also, for your users to know about them.

  • optionsFirst, by default false. If set to true will disallow mixing options and positional argument. I.e. after first positional argument, all arguments will be interpreted as positional even if the look like options. This can be used for strict compatibility with POSIX, or if you want to dispatch your arguments to other programs.

Docopt\Handler->handle() takes one required argument:

• doc is a string that contains a help message that will be parsed to create the option parser. The simple rules of how to write such a help message are given in next sections. Here is a quick example of such a string:

.. code:: php

<?php
$doc = <<<DOC
Usage: my_program.php [-hso FILE] [--quiet | --verbose] [INPUT ...]

-h --help    show this
-s --sorted  sorted output
-o FILE      specify output file [default: ./test.txt]
--quiet      print less text
--verbose    print more text

DOC;

The return value of handle() is a simple associative array with options, arguments and commands as keys, spelled exactly like in your help message. Long versions of options are given priority. For example, if you invoke the top example as::

naval_fate.php ship Guardian move 100 150 --speed=15

the return dictionary will be:

.. code:: php

<?php
array(
  '--drifting'=>false,         'mine'=>false,
  '--help'=>false,             'move'=>true,
  '--moored'=>false,           'new'=>false,
  '--speed'=>'15',             'remove'=>false,
  '--version'=>false,          'set'=>false,
  '<name>'=>array('Guardian'), 'ship'=>true,
  '<x>'=>'100',                'shoot'=>false,
  '<y>'=>'150'
);

Help message format

Help message consists of 2 sections:

• Usage section, starting with Usage: e.g.::

  Usage: my_program.php [-hso FILE] [--quiet | --verbose] [INPUT ...]

• Option section, starting with Options: e.g.::

  Options: -h --help show this -s --sorted sorted output -o FILE specify output file [default: ./test.txt] --quiet print less text --verbose print more text

Sections consist of a header and a body. The section b