| Metadata-Version: 2.1 |
| Name: shellingham |
| Version: 1.5.4 |
| Summary: Tool to Detect Surrounding Shell |
| Home-page: https://github.com/sarugaku/shellingham |
| Author: Tzu-ping Chung |
| Author-email: uranusjr@gmail.com |
| License: ISC License |
| Keywords: shell |
| Classifier: Development Status :: 3 - Alpha |
| Classifier: Environment :: Console |
| Classifier: Intended Audience :: Developers |
| Classifier: License :: OSI Approved :: ISC License (ISCL) |
| Classifier: Operating System :: OS Independent |
| Classifier: Programming Language :: Python :: 3 :: Only |
| Classifier: Programming Language :: Python :: 3.7 |
| Classifier: Programming Language :: Python :: 3.8 |
| Classifier: Programming Language :: Python :: 3.9 |
| Classifier: Programming Language :: Python :: 3.10 |
| Classifier: Programming Language :: Python :: 3.11 |
| Classifier: Programming Language :: Python :: 3.12 |
| Classifier: Topic :: Software Development :: Libraries :: Python Modules |
| Requires-Python: >=3.7 |
| Description-Content-Type: text/x-rst |
| License-File: LICENSE |
|
|
| ============================================= |
| Shellingham: Tool to Detect Surrounding Shell |
| ============================================= |
|
|
| .. image:: https://img.shields.io/pypi/v/shellingham.svg |
| :target: https://pypi.org/project/shellingham/ |
|
|
| Shellingham detects what shell the current Python executable is running in. |
|
|
|
|
| Usage |
| ===== |
|
|
| .. code-block:: python |
|
|
| >>> import shellingham |
| >>> shellingham.detect_shell() |
| ('bash', '/bin/bash') |
|
|
| ``detect_shell`` pokes around the process's running environment to determine |
| what shell it is run in. It returns a 2-tuple: |
|
|
| * The shell name, always lowercased. |
| * The command used to run the shell. |
|
|
| ``ShellDetectionFailure`` is raised if ``detect_shell`` fails to detect the |
| surrounding shell. |
|
|
|
|
| Notes |
| ===== |
|
|
| * The shell name is always lowercased. |
| * On Windows, the shell name is the name of the executable, minus the file |
| extension. |
|
|
|
|
| Notes for Application Developers |
| ================================ |
|
|
| Remember, your application's user is not necessarily using a shell. |
| Shellingham raises ``ShellDetectionFailure`` if there is no shell to detect, |
| but *your application should almost never do this to your user*. |
|
|
| A practical approach to this is to wrap ``detect_shell`` in a try block, and |
| provide a sane default on failure |
|
|
| .. code-block:: python |
|
|
| try: |
| shell = shellingham.detect_shell() |
| except shellingham.ShellDetectionFailure: |
| shell = provide_default() |
|
|
|
|
| There are a few choices for you to choose from. |
|
|
| * The POSIX standard mandates the environment variable ``SHELL`` to refer to |
| "the user's preferred command language interpreter". This is always available |
| (even if the user is not in an interactive session), and likely the correct |
| choice to launch an interactive sub-shell with. |
| * A command ``sh`` is almost guaranteed to exist, likely at ``/bin/sh``, since |
| several POSIX tools rely on it. This should be suitable if you want to run a |
| (possibly non-interactive) script. |
| * All versions of DOS and Windows have an environment variable ``COMSPEC``. |
| This can always be used to launch a usable command prompt (e.g. `cmd.exe` on |
| Windows). |
|
|
| Here's a simple implementation to provide a default shell |
|
|
| .. code-block:: python |
|
|
| import os |
|
|
| def provide_default(): |
| if os.name == 'posix': |
| return os.environ['SHELL'] |
| elif os.name == 'nt': |
| return os.environ['COMSPEC'] |
| raise NotImplementedError(f'OS {os.name!r} support not available') |
|
|
