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Writing Ergonomica Commands

To make commands in Ergonomica, you have two options. The first is to make a "shell command"; this is what is found in the Ergonomica standard library. This takes in, and only takes in, an argc argument. This is an ArgumentsContainer object. argc.ns is the Ergonomica namespace, argc.env is the Environment, and argc.args are the command-line arguments parsed with docopt according to the docstring. Here's the implementation of the standard library ls command for reference:

#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
[lib/lib/ls.py]

Defines the "ls" command.
"""

import os
import datetime
from ergonomica.lib.util.util import expand_path
from ergonomica.lib.lang.stat import creation_date


def ls(argc):
    """
    ls: List files in a directory.

    Usage:
        ls [DIR] [-c | --count-files] [-d | --date] [-h | --hide-dotfiles]

    Options:
        -d --date           Show file creation dates.
        -h --hide-dotfiles  Ignore dotfiles.
        -c --count-files    Return the number of files in a directory.

    Examples:
        ls $
    """


    file_filter = lambda x: True

    if argc.args['--hide-dotfiles']:
        file_filter = lambda x: not x.startswith(".")

    # date processing from numerical time
    date = lambda t: str(datetime.datetime.fromtimestamp(creation_date(t))) +\
           " " if argc.args['--date'] else ""

    if not argc.args['DIR']:
        argc.args['DIR'] = "."


    files = [date(x) + x for x in os.listdir(expand_path(argc.env, argc.args['DIR']))
             if file_filter(x)]


    if argc.args['--count-files']:
        return len(files)
    else:
        return files

exports = {'ls': ls}

Other commands are just regular Python ones, like builtin randint:

def randint(lower, upper=None):
    if not upper:
        lower, upper = 0, lower

    return random.randint(lower, upper)

Writing Ergonomica Scripts

Ergonomica, in addition to being a shell language, supports writing scripts in it. These scripts are simply a series of commands that are executed and their output printed, just as they would be at the REPL. For example, let's consider a script that'll remove all "bad" files (aka those that are not Python files ;) ). This would be a one liner,

#!/usr/bin/env ergo

find file ".*\.[^py]" | rm {0}

Then, if this command were in your PATH, it would be callable as an Ergonomica script, or if it were in the current directory in a POSIX-shell and you had execute permissions, ./command_name.ergo would execute it. From within Ergonomica, these scripts can be executed as simply as:

ergo command_name.ergo

Additionally, you can add the --login flag in order to load ~/.ergo/.ergo_profile.