Command line argument parser
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!):
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.
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.
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.
… 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… 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… 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 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 body can begin on
the same line as the header, but if it spans multiple lines, it must be
indented. A section is terminated by an empty line or a string with no
indentation::
Section header: Section body
Section header:
Section body, which is indented at least
one space or tab from the section header
Section header: Section body, which is indented at least
one space or tab from the section header
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:
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 your 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> or ARGUMENTS,
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 as my_program.php (--path=<path> <file>...). (Note, “required options” might be not
a good idea for your users).
| (pipe) mutually 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
more FILE-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 that
stdin 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 occurrences 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'].
The Option section is an optional section that contains a list of
options that can document or supplement your usage pattern.
It is necessary to list option descriptions in order to specify:
The rules are as follows:
Every line in the options section body that starts with one or more
horizontal whitespace characters, followed by - or -- 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
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
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 interpreted as string. If it is repeatable, it will be
splited into a list on whitespace::
Usage: my_program.php [–repeatable=
[–another-repeatable=
[–not-repeatable=
–repeatable=
–another-repeatable=
–not-repeatable=
We have an extensive list of examples <https://github.com/docopt/docopt/tree/master/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 (with 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 <https://github.com/docopt/docopt/tree/master/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 <http://github.com/docopt/docopt>_ for more info
on developing.