abcmd

A library for wrapping shell commands with static configuration.

Usage

The library provides the abcmd.Command ABC that can be used to create shell command wrappers.

Subclassing abcmd.Command requires the following methods to be implemented:

• run

in addition the following methods are optional and will run only if implemented:

• dont_run
• handle_error
• before_run
• after_run

The decorator abcmd.error_handler is used to decorate subclass methods which are called only for the matching errors, errors that don't have specific handlers will fall back to calling the handle_error method if it's implemented.

Examples

Automating backup of dotfiles

First we subclass Command and describe the procedure:

import datetime
import os

import abcmd

class Backup(abcmd.Command):
    make = 'mkdir {directory}'
    copy = 'cp {files} {directory}'
    sync = 'rsync {directory} {user}@{server}:'

    def run(self, *args, **kwargs):
        os.chdir(os.environ['HOME'])
        self.make()
        self.copy()
        self.sync()

    def dont_run(self, *args, **kwargs):
        # don't run between working hours
        return dt.datetime.now().hour in range(8, 16)

    def handle_error(self, cmd, error):
        # if the backup directory exists ignore the error and continue
        return cmd.startswith('mkdir') and error.endswith('File exists')

then we instantiate with a mapping that is used to render the templates, this will return a callable object that when called will run the procedure:

config = {
    'user': 'laerus',
    'directory': 'dotfiles',
    'files': ['.vimrc', '.bashrc', '.inputrc'],
    'server': '192.168.1.10'
}

runner = Backup(config)
runner()

This would be equivalent with running the following commands:

$ cd ~
$ mkdir dotfiles
$ cp .vimrc .bashrc .inputrc dotfiles
$ rsync dotfiles laerus@192.168.1.10:

Installation

$ pip install abcmd

Compatibility

python3.5+

Licence

MIT

Authors

abcmd was written by Konstantinos Tsakiltzidis.