This is a straight PHP transliteration of Vladimir Keleshev's brilliant 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.
Video introduction to docopt: PyCon UK 2012: Create *beautiful* command-line interfaces with Python
New in version 0.6.0:
- New argument
options_first
, disallows interspersing options and arguments. If you supplyoptions_first=True
todocopt
, it will interpret all arguments as positional arguments after first positional argument.- If option with argument could be repeated, its default value will be interpreted as space-separated list. E.g. with
[default: ./here ./there]
will be interpreted as['./here', './there']
.Breaking changes:
- Meaning of
[options]
shortcut slightly changed. Previously it ment "any known option". Now it means "any option not in usage-pattern". This avoids the situation when an option is allowed to be repeated unintentionaly.argv
isNone
by default, notsys.argv[1:]
. This allowsdocopt
to always use the latestsys.argv
, notsys.argv
during import time.
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:
<?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');
$args = Docopt\docopt($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.
docopt.php
is available on Packagist.
Create a composer.json
file for your project
{
"require": {
"docopt/docopt": "0.5.0"
}
}
Install using composer:
php composer.phar install
Alternatively, you can just drop docopt.php file into your project--it is self-contained. Get source on github.
docopt.php
is tested with PHP 5.3
<?php
require('/path/to/src/docopt.php');
// short form
$args = Docopt\docopt($sdoc);
// long form (equivalent to short)
$params = array(
'argv'=>array_slice($_SERVER['argv'], 1),
'help'=>true,
'version'=>null,
'optionsFirst'=>false,
);
$args = Docopt\docopt($doc, $params);
docopt
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:
<?php
$doc = <<<DOC
Usage: my_program.php [-hso FILE] [--quiet | --verbose] [INPUT ...]
-h --help show this
-s --sorted sorted output
-o FILE specify output file [default: ./test.txt]
--quiet print less text
--verbose print more text
DOC;
params
is an optional array of additional data to influencedocopt
. The following keys are supported:argv
is an optional argument vector; by defaultdocopt
uses the argument vector passed to your program ($_SERVER['argv']
). Alternatively you can supply a list of strings likearray('--verbose', '-o', 'hai.txt')
.help
, by defaulttrue
, specifies whether the parser shouldautomatically 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), sethelp
tofalse
.
version
, by defaultnull
, 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 defaultfalse
. If set totrue
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.
The return value 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:
<?php
array(
'--drifting'=>false, 'mine'=>false,
'--help'=>false, 'move'=>true,
'--moored'=>false, 'new'=>true,
'--speed'=>'15', 'remove'=>true,
'--version'=>false, 'set'=>true,
'<name>'=>array('Guardian'), 'ship'=>true,
'<x>'=>'100', 'shoot'=>false,
'<y>'=>'150'
);
Help message consists of 2 parts:
Usage pattern, e.g.:
Usage: my_program.php [-hso FILE] [--quiet | --verbose] [INPUT ...]
Option descriptions, e.g.:
-h --help show this -s --sorted sorted output -o FILE specify output file [default: ./test.txt] --quiet print less text --verbose print more text
Their format is described below; other text is ignored.
Usage pattern is a substring of doc
that starts with
usage:
(case insensitive) and ends with a visibly empty line.
Minimum example:
Usage: my_program.php
The first word after usage:
is interpreted as your program's name.
You can specify your program's name several times to signify several
exclusive patterns:
Usage: my_program.php FILE my_program.php COUNT FILE
Each pattern can consist of the following elements:
- <arguments>, ARGUMENTS. Arguments are specified as either
upper-case words, e.g.
my_program.php CONTENT-PATH
or words surrounded by angular brackets:my_program.php <content-path>
. - --options. Options are words started with dash (
-
), e.g.--output
,-o
. You can "stack" several of one-letter options, e.g.-oiv
which will be the same as-o -i -v
. The options can have arguments, e.g.--input=FILE
or-i FILE
or even-iFILE
. However it is important that you specify option descriptions if you want for option to have an argument, a default value, or specify synonymous short/long versions of option (see next section on option descriptions). - commands are words that do not follow the described above
conventions of
--options
or<arguments>
orARGUMENTS
, plus two special commands: dash "-
" and double dash "--
" (see below).
Use the following constructs to specify patterns:
- [ ] (brackets) optional elements. e.g.:
my_program.php [-hvqo FILE]
- ( ) (parens) required elements. All elements that are not
put in [ ] are also required, e.g.:
my_program.php --path=<path> <file>...
is the same asmy_program.php (--path=<path> <file>...)
. (Note, "required options" might be not a good idea for your users). - | (pipe) mutualy exclusive elements. Group them using (
) if one of the mutually exclusive elements is required:
my_program.php (--clockwise | --counter-clockwise) TIME
. Group them using [ ] if none of the mutually-exclusive elements are required:my_program.php [--left | --right]
. - ... (ellipsis) one or more elements. To specify that
arbitrary number of repeating elements could be accepted, use
ellipsis (
...
), e.g.my_program.php FILE ...
means one or moreFILE
-s are accepted. If you want to accept zero or more elements, use brackets, e.g.:my_program.php [FILE ...]
. Ellipsis works as a unary operator on the expression to the left. - [options] (case sensitive) shortcut for any options. You can
use it if you want to specify that the usage pattern could be
provided with any options defined below in the option-descriptions
and do not want to enumerate them all in usage-pattern. -
"
[--]
". Double dash "--
" is used by convention to separate positional arguments that can be mistaken for options. In order to support this convention add "[--]
" to you usage patterns. - "[-]
". Single dash "-
" is used by convention to signify thatstdin
is used instead of a file. To support this add "[-]
" to you usage patterns. "-
" act as a normal command.
If your pattern allows to match argument-less option (a flag) several times:
Usage: my_program.php [-v | -vv | -vvv]
then number of occurences of the option will be counted. I.e.
args['-v']
will be 2
if program was invoked as my_program
-vv
. Same works for commands.
If your usage patterns allows to match same-named option with argument or positional argument several times, the matched arguments will be collected into a list:
Usage: my_program.php <file> <file> --path=<path>...
I.e. invoked with my_program.php file1 file2 --path=./here
--path=./there
the returned dict will contain args['<file>'] ==
['file1', 'file2']
and args['--path'] == ['./here', './there']
.
Option descriptions consist of a list of options that you put below your usage patterns.
It is necessary to list option descriptions in order to specify:
- synonymous short and long options,
- if an option has an argument,
- if option's argument has a default value.
The rules are as follows:
Every line in
doc
that starts with-
or--
(not counting spaces) is treated as an option description, e.g.:Options: --verbose # GOOD -o FILE # GOOD Other: --bad # BAD, line does not start with dash "-"
To specify that option has an argument, put a word describing that argument after space (or equals "
=
" sign) as shown below. Follow either <angular-brackets> or UPPER-CASE convention for options' arguments. You can use comma if you want to separate options. In the example below, both lines are valid, however you are recommended to stick to a single style.:-o FILE --output=FILE # without comma, with "=" sign -i <file>, --input <file> # with comma, wihtout "=" sing
Use two spaces to separate options with their informal description:
--verbose More text. # BAD, will be treated as if verbose option had # an argument "More", so use 2 spaces instead -q Quit. # GOOD -o FILE Output file. # GOOD --stdout Use stdout. # GOOD, 2 spaces
If you want to set a default value for an option with an argument, put it into the option-description, in form
[default: <my-default-value>]
:--coefficient=K The K coefficient [default: 2.95] --output=FILE Output file [default: test.txt] --directory=DIR Some directory [default: ./]
If the option is not repeatable, the value inside
[default: ...]
will be interpeted as string. If it is repeatable, it will be splited into a list on whitespace:Usage: my_program.php [--repeatable=<arg> --repeatable=<arg>] [--another-repeatable=<arg>]... [--not-repeatable=<arg>] # will be ['./here', './there'] --repeatable=<arg> [default: ./here ./there] # will be ['./here'] --another-repeatable=<arg> [default: ./here] # will be './here ./there', because it is not repeatable --not-repeatable=<arg> [default: ./here ./there]
We have an extensive list of examples which cover every aspect of functionality of docopt. Try them out, read the source if in doubt.
If you want to split your usage-pattern into several, implement
multi-level help (whith separate help-screen for each subcommand),
want to interface with existing scripts that don't use docopt, or
you're building the next "git", you will need the new options_first
parameter (described in API section above). To get you started quickly
we implemented a subset of git command-line interface as an example:
examples/git
docopt does one thing and does it well: it implements your command-line interface. However it does not validate the input data. You should supplement docopt with a validation library when your validation requirements extend beyond whether input is optional or required.
See the Python version's page for more info on developing.