Skip to main content

Shell interface for docopt, the command-line interface description language.

Project description

================================================================================
docopts
================================================================================
--------------------------------------------------------------------------------
shell interface for docopt, the CLI description language
--------------------------------------------------------------------------------
:Author: `Lari Rasku <rasku@lavabit.com>`_
:Date: 2012-10-16
:Copyright: `MIT <http://opensource.org/licenses/MIT>`_
:Version: 0.5.0+fix
:Manual section: 1

SYNOPSIS
================================================================================
``docopts`` [*options*] *doc* *version* [--] [*argv*...]

DESCRIPTION
================================================================================
``docopts`` parses the command line argument vector *argv* according to the
`docopt <http://docopt.org>`_ string *doc* and echoes the results to standard
output as a snippet of Bash source code. Passing this snippet as an argument to
`eval(1) <http://man.cx/eval(1)>`_ is sufficient for handling the CLI needs of
most scripts.

If *argv* matches one of the usage patterns defined in *doc*, ``docopts``
generates code for storing the parsed arguments as Bash variables. As most
command line argument names are not valid Bash identifiers, some name mangling
will take place:

* ``<Angle_Brackets>``: ``Angle_Brackets``
* ``UPPER-CASE``: ``UPPER_CASE``
* ``--Long-Option``: ``Long_Option``
* ``-S``: ``S``

If one of the argument names cannot be mangled into a valid Bash identifier,
or two argument names map to the same variable name, ``docopt`` will exit with
an error, and you should really rethink your CLI. The ``--`` and ``-``
commands will not be stored.

Alternatively, ``docopts`` can be invoked with the ``-A <name>`` option, which
stores the parsed arguments as fields of a Bash 4 associative array called
``<name>`` instead. However, as Bash does not natively support nested arrays,
they are faked for repeatable arguments with the following access syntax::

${args[ARG,#]} # the number of arguments to ARG
${args[ARG,0]} # the first argument to ARG
${args[ARG,1]} # the second argument to ARG, etc.

The arguments are stored as follows:

* Non-repeatable, valueless arguments: `true(1) <http://man.cx/true(1)>`_
if found, `false(1) <http://man.cx/false(1)>`_ if not
* Repeatable valueless arguments: the count of their instances in *argv*
* Non-repeatable arguments with values: the value as a string if found,
the empty string if not
* Repeatable arguments with values: a Bash array of the parsed values

Unless the ``--no-help`` option is given, ``docopts`` handles the ``--help``
and ``--version`` options and their possible aliases specially,
generating code for printing the relevant message to standard output and
terminating successfully if either option is encountered when parsing *argv*.
Note however that this also requires listing the relevant option in
*doc*, and in ``--version``'s case, invoking ``docopts`` with a non-empty
*version* string.

If *argv* does not match any usage pattern in *doc*, ``docopts`` will generate
code for exiting the program with status 64 (``EX_USAGE`` in
`sysexits(3) <http://man.cx/sysexits(3)>`_) and printing a diagnostic error
message.

ARGUMENTS
================================================================================
:doc: The help message in docopt format. If ``-`` is
given, read the help message from standard
input.
:version: A version message. If an empty argument is
given via ``''``, no version message is used.
If ``-`` is given, the version message is read
from standard input. The version message is
read after the help message if both are given
via standard input.

OPTIONS
================================================================================
-A <name> Export the arguments as a Bash 4.x associative
array called *name*.
-s <sep>, --separator=<sep> The string to use to separate *doc* from
*version* when both are given via standard
input [default: ``----``]
-H, --no-help Don't handle ``--help`` and ``--version``
specially.
-h, --help Show help options.
-V, --version Print program version.

EXAMPLES
================================================================================
Read *doc* and *version* from standard input::

eval "$(docopts - - -- "$@" <<EOF
Usage: rock [options] <argv>...

--verbose Generate verbose messages.
--help Show help options.
--version Print program version.
----
rock 0.1.0
Copyright (C) 200X Thomas Light
License RIT (Robot Institute of Technology)
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
EOF
)"

if $verbose ; then
echo "Hello, world!"
fi

Parse *doc* and *version* from script comments and pass them as command line
arguments::

## rock 0.1.0
## Copyright (C) 200X Thomas Light
## License RIT (Robot Institute of Technology)
## This is free software: you are free to change and redistribute it.
## There is NO WARRANTY, to the extent permitted by law.

### Usage: rock [options] <argv>...
###
### --help Show help options.
### --version Print program version.

help=$(grep "^### " "$0" | cut -c 5-)
version=$(grep "^## " "$0" | cut -c 4-)
eval "$(docopts "$help" "$version" -- "$@")"

for arg in "${argv[@]}"; do
echo "$arg"
done

Using the associative array::

eval "$(docopts -A args "$help" "" -- "$@")"

if ${args[subcommand]} ; then
echo "subcommand was given"
fi

if [ -n "${args[--long-option-with-argument]}" ] ; then
echo "${args[--long-option-with-argument]}"
else
echo "--long-option-with-argument was not given"
fi

i=0
while [[ $i -lt ${args[<argument-with-multiple-values>,#]} ]] ; do
echo "${args[<argument-with-multiple-values>,$i]}"
i=$[$i+1]
done

INSTALLATION
================================================================================
To install ``docopts`` for every user, extract the release archive and execute
the following command in it::

python setup.py install

To install ``docopts`` just for you, use this instead::

python setup.py install --user

Alternatively, you can simply copy the ``docopts`` file to anywhere on your
``PATH``; it is self-contained.

VERSIONING
================================================================================
The ``docopts`` version number always matches that of the
`docopt Python reference implementation <https://github.com/docopt/docopt>`_
version against which it was built. As ``docopt`` follows semantic versioning,
``docopts`` should work with any ``docopt`` release it shares the major version
number with; however, as both ``docopts`` and ``docopt`` are in major version
number 0 at the moment of writing this (2012-10-09), ``docopts`` can only be
relied to work with an installation of ``docopt`` with the exact same version
number.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

docopts-0.5.0-fix.tar.gz (6.0 kB view hashes)

Uploaded Source

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page