diff options
| -rwxr-xr-x | examples/bash_completion.py | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/examples/bash_completion.py b/examples/bash_completion.py new file mode 100755 index 00000000..6a5a2a89 --- /dev/null +++ b/examples/bash_completion.py @@ -0,0 +1,98 @@ +#!/usr/bin/env python3 +# coding=utf-8 +# PYTHON_ARGCOMPLETE_OK - This is required at the beginning of the file to enable argcomplete support +"""A simple example demonstrating integration with argcomplete. + +This example demonstrates how to achieve automatic auto-completion of argparse arguments for a command-line utility +(CLU) in the Bash shell. + +Realistically it will probably only work on Linux and then only in a Bash shell. With some effort you can probably get +it to work on macOS or Windows Subsystem for Linux (WSL); but then again, specifically within a Bash shell. This +automatic Bash completion integration with the argcomplete module is included within cmd2 in order to assist developers +with providing a the best possible out-of-the-box experience with their cmd2 applications, which in many cases will +accept argparse arguments on the command-line when executed. But from an architectural point of view, the +"argcomplete_bridge" functionality within cmd2 doesn't really depend on the rest of cmd2 and could be used in your own +CLU which doesn't use cmd2. + +WARNING: For this example to work correctly you need the argcomplete module installed and activated: + pip install argcomplete + activate-global-python-argcomplete +Please see https://github.com/kislyuk/argcomplete for more information on argcomplete. +""" +import argparse + +optional_strs = ['Apple', 'Banana', 'Cranberry', 'Durian', 'Elderberry'] + +bash_parser = argparse.ArgumentParser(prog='base') + +bash_parser.add_argument('option', choices=['load', 'export', 'reload']) + +bash_parser.add_argument('-u', '--user', help='User name') +bash_parser.add_argument('-p', '--passwd', help='Password') + +input_file = bash_parser.add_argument('-f', '--file', type=str, help='Input File') + +if __name__ == '__main__': + from cmd2.argcomplete_bridge import bash_complete + # bash_complete flags this argument telling AutoCompleter to yield to bash to perform + # tab completion of a file path + bash_complete(input_file) + +flag_opt = bash_parser.add_argument('-o', '--optional', help='Optional flag with choices') +setattr(flag_opt, 'arg_choices', optional_strs) + +# Handle bash completion if it's installed +# This early check allows the script to bail out early to provide tab-completion results +# to the argcomplete library. Putting this at the end of the file would cause the full application +# to load fulfill every tab-completion request coming from bash. This can cause a notable delay +# on the bash prompt. +try: + # only move forward if we can import CompletionFinder and AutoCompleter + from cmd2.argcomplete_bridge import CompletionFinder + from cmd2.argparse_completer import AutoCompleter + import sys + if __name__ == '__main__': + completer = CompletionFinder() + + # completer will return results to argcomplete and exit the script + completer(bash_parser, AutoCompleter(bash_parser)) +except ImportError: + pass + +# Intentionally below the bash completion code to reduce tab completion lag +import cmd2 + + +class DummyApp(cmd2.Cmd): + """ + Dummy cmd2 app + """ + + def __init__(self): + super().__init__() + + +if __name__ == '__main__': + args = bash_parser.parse_args() + + # demonstrates some handling of the command line parameters + + if args.user is None: + user = input('Username: ') + else: + user = args.user + + if args.passwd is None: + import getpass + password = getpass.getpass() + else: + password = args.passwd + + if args.file is not None: + print('Loading file: {}'.format(args.file)) + + # Clear the argumentns so cmd2 doesn't try to parse them + sys.argv = sys.argv[:1] + + app = DummyApp() + app.cmdloop() |