Scripts

• Omit the extension and specify the type in the file with a #! so the caller doesn’t need to know the language of the script

To make it runnable:

chmod a+x script
mv script ~/bin # or sudo mv script /usr/local/bin

Bash

• Use if the command is simple

• Or, if you need to pipe through a lot of other commands

As a standalone script:

#!/bin/bash

if [[ $# -eq 0 ]] ; then
    echo 'Usage: ...'
    exit 1
fi

echo $1 | foo | bar

As an inline function in .bashrc:

my-function ()
{
    echo "$1" | ...
}

Python

• Use if the command needs to do a lot of manipulation of data structures

• Use if the command requires a lot of argument parsing

• Use argparse

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import argparse


def perform_op(arg1, flag1):
    # ...

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='Some script')
    parser.add_argument("arg1")
    parser.add_argument("--flag1", action="store_true")
    args = parser.parse_args()
    perform_op(args.arg1, args.flag1)