Metadata-Version: 1.0
Name: executor
Version: 8.3
Summary: Programmer friendly subprocess wrapper
Home-page: https://executor.readthedocs.org
Author: Peter Odding
Author-email: peter@peterodding.com
License: UNKNOWN
Description: executor: Programmer friendly subprocess wrapper
        ================================================
        
        .. image:: https://travis-ci.org/xolox/python-executor.svg?branch=master
           :target: https://travis-ci.org/xolox/python-executor
        
        .. image:: https://coveralls.io/repos/xolox/python-executor/badge.png?branch=master
           :target: https://coveralls.io/r/xolox/python-executor?branch=master
        
        The `executor` package is a simple wrapper for Python's subprocess_ module
        that makes it very easy to handle subprocesses on UNIX systems with proper
        escaping of arguments and error checking:
        
         * An object oriented interface is used to execute commands using sane but
           customizable (and well documented) defaults.
        
         * Remote commands (executed over SSH_) are supported using the same object
           oriented interface.
        
         * There's also support for executing a group of commands concurrently in
           what's called a "command pool". The concurrency level can be customized and
           of course both local and remote commands are supported.
        
        The package is currently tested on Python 2.6, 2.7, 3.4 and PyPy. For usage
        instructions please refer to following sections and the documentation_.
        
        .. contents::
           :local:
           :depth: 2
        
        Installation
        ------------
        
        The `executor` package is available on PyPI_ which means installation should be
        as simple as:
        
        .. code-block:: sh
        
           $ pip install executor
        
        There's actually a multitude of ways to install Python packages (e.g. the `per
        user site-packages directory`_, `virtual environments`_ or just installing
        system wide) and I have no intention of getting into that discussion here, so
        if this intimidates you then read up on your options before returning to these
        instructions ;-).
        
        Usage
        -----
        
        There are two ways to use the `executor` package: As the command line program
        ``executor`` and as a Python API. The command line interface is described below
        and there are also some examples of simple use cases of the Python API.
        
        .. contents::
           :local:
           :depth: 1
        
        Command line
        ~~~~~~~~~~~~
        
        .. A DRY solution to avoid duplication of the `executor --help' text:
        ..
        .. [[[cog
        .. from humanfriendly.usage import inject_usage
        .. inject_usage('executor.cli')
        .. ]]]
        
        **Usage:** `executor [OPTIONS] COMMAND ...`
        
        Easy subprocess management on the command line based on the Python package with the same name. The "executor" program runs external commands with support for timeouts, dynamic startup delay (fudge factor) and exclusive locking.
        
        You can think of "executor" as a combination of the "flock" and "timelimit" programs with some additional niceties (namely the dynamic startup delay and integrated system logging on UNIX platforms).
        
        **Supported options:**
        
        .. csv-table::
           :header: Option, Description
           :widths: 30, 70
        
        
           "``-t``, ``--timeout=LIMIT``","Set the time after which the given command will be aborted. By default
           ``LIMIT`` is counted in seconds. You can also use one of the suffixes ""s""
           (seconds), ""m"" (minutes), ""h"" (hours) or ""d"" (days).
           "
           "``-f``, ``--fudge-factor=LIMIT``","This option controls the dynamic startup delay (fudge factor) which is
           useful when you want a periodic task to run once per given interval but the
           exact time is not important. Refer to the ``--timeout`` option for acceptable
           values of ``LIMIT``, this number specifies the maximum amount of time to sleep
           before running the command (the minimum is zero, otherwise you could just
           include the command ""sleep N && ..."" in your command line :-).
           "
           "``-e``, ``--exclusive``","Use an interprocess lock file to guarantee that executor will never run
           the external command concurrently. Refer to the ``--lock-timeout`` option
           to customize blocking / non-blocking behavior. To customize the name
           of the lock file you can use the ``--lock-file`` option.
           "
           "``-T``, ``--lock-timeout=LIMIT``","By default executor tries to claim the lock and if it fails it will exit
           with a nonzero exit code. This option can be used to enable blocking
           behavior. Refer to the ``--timeout`` option for acceptable values of ``LIMIT``.
           "
           "``-l``, ``--lock-file=NAME``","Customize the name of the lock file. By default this is the base name of
           the external command, so if you're running something generic like ""bash""
           or ""python"" you might want to change this :-).
           "
           "``-v``, ``--verbose``","Make more noise than usual (increase logging verbosity).
           "
           "``-q``, ``--quiet``","Make less noise than usual (decrease logging verbosity).
           "
           "``-h``, ``--help``","Show this message and exit.
           "
        
        .. [[[end]]]
        
        Python API
        ~~~~~~~~~~
        
        Below are some examples of how versatile the `execute()`_ function is. Refer to
        the API documentation on `Read the Docs`_ for (a lot of) other use cases.
        
        .. contents::
           :local:
        
        Checking status codes
        +++++++++++++++++++++
        
        By default the status code of the external command is returned as a boolean:
        
        >>> from executor import execute
        >>> execute('true')
        True
        
        If an external command exits with a nonzero status code an exception is raised,
        this makes it easy to do the right thing (never forget to check the status code
        of an external command without having to write a lot of repetitive code):
        
        >>> execute('false')
        Traceback (most recent call last):
          File "executor/__init__.py", line 124, in execute
            cmd.start()
          File "executor/__init__.py", line 516, in start
            self.wait()
          File "executor/__init__.py", line 541, in wait
            self.check_errors()
          File "executor/__init__.py", line 568, in check_errors
            raise ExternalCommandFailed(self)
        executor.ExternalCommandFailed: External command failed with exit code 1! (command: bash -c false)
        
        The ExternalCommandFailed_ exception exposes ``command`` and ``returncode``
        attributes. If you know a command is likely to exit with a nonzero status code
        and you want `execute()`_ to simply return a boolean you can do this instead:
        
        >>> execute('false', check=False)
        False
        
        Providing input
        +++++++++++++++
        
        Here's how you can provide input to an external command:
        
        >>> execute('tr a-z A-Z', input='Hello world from Python!\n')
        HELLO WORLD FROM PYTHON!
        True
        
        Getting output
        ++++++++++++++
        
        Getting the output of external commands is really easy as well:
        
        >>> execute('hostname', capture=True)
        'peter-macbook'
        
        Running commands as root
        ++++++++++++++++++++++++
        
        It's also very easy to execute commands with super user privileges:
        
        >>> execute('echo test > /etc/hostname', sudo=True)
        [sudo] password for peter: **********
        True
        >>> execute('hostname', capture=True)
        'test'
        
        Enabling logging
        ++++++++++++++++
        
        If you're wondering how prefixing the above command with ``sudo`` would
        end up being helpful, here's how it works:
        
        >>> import logging
        >>> logging.basicConfig()
        >>> logging.getLogger().setLevel(logging.DEBUG)
        >>> execute('echo peter-macbook > /etc/hostname', sudo=True)
        DEBUG:executor:Executing external command: sudo bash -c 'echo peter-macbook > /etc/hostname'
        
        Running remote commands
        +++++++++++++++++++++++
        
        To run a command on a remote system using SSH_ you can use the RemoteCommand_
        class, it works as follows:
        
        >>> from executor.ssh.client import RemoteCommand
        >>> cmd = RemoteCommand('localhost', 'echo $SSH_CONNECTION', capture=True)
        >>> cmd.start()
        >>> cmd.output
        '127.0.0.1 57255 127.0.0.1 22'
        
        Running remote commands concurrently
        ++++++++++++++++++++++++++++++++++++
        
        The `foreach()`_ function wraps the RemoteCommand_ and CommandPool_ classes to
        make it very easy to run a remote command concurrently on a group of hosts:
        
        >>> from executor.ssh.client import foreach
        >>> from pprint import pprint
        >>> hosts = ['127.0.0.1', '127.0.0.2', '127.0.0.3', '127.0.0.4']
        >>> commands = foreach(hosts, 'echo $SSH_CONNECTION')
        >>> pprint([cmd.output for cmd in commands])
        ['127.0.0.1 57278 127.0.0.1 22',
         '127.0.0.1 52385 127.0.0.2 22',
         '127.0.0.1 49228 127.0.0.3 22',
         '127.0.0.1 40628 127.0.0.4 22']
        
        Contact
        -------
        
        The latest version of `executor` is available on PyPI_ and GitHub_. The
        documentation is hosted on `Read the Docs`_. For bug reports please create an
        issue on GitHub_. If you have questions, suggestions, etc. feel free to send me
        an e-mail at `peter@peterodding.com`_.
        
        License
        -------
        
        This software is licensed under the `MIT license`_.
        
        © 2015 Peter Odding.
        
        .. External references:
        .. _CommandPool: https://executor.readthedocs.org/en/latest/#executor.concurrent.CommandPool
        .. _documentation: https://executor.readthedocs.org
        .. _execute(): http://executor.readthedocs.org/en/latest/#executor.execute
        .. _ExternalCommandFailed: http://executor.readthedocs.org/en/latest/#executor.ExternalCommandFailed
        .. _foreach(): https://executor.readthedocs.org/en/latest/#executor.ssh.client.foreach
        .. _GitHub: https://github.com/xolox/python-executor
        .. _MIT license: http://en.wikipedia.org/wiki/MIT_License
        .. _per user site-packages directory: https://www.python.org/dev/peps/pep-0370/
        .. _peter@peterodding.com: peter@peterodding.com
        .. _PyPI: https://pypi.python.org/pypi/executor
        .. _Read the Docs: https://executor.readthedocs.org/en/latest/#api-documentation
        .. _RemoteCommand: https://executor.readthedocs.org/en/latest/#executor.ssh.client.RemoteCommand
        .. _SSH: https://en.wikipedia.org/wiki/Secure_Shell
        .. _subprocess: https://docs.python.org/2/library/subprocess.html
        .. _virtual environments: http://docs.python-guide.org/en/latest/dev/virtualenvs/
        
Platform: UNKNOWN
