Script-Cook

Simple bash library that generates all the boilerplate for your bash scripts. By providing necessary information using an associative array (old way) or a string matrix that follows a convention (new way), you get the following:

• Check if all required arguments are provided
• Check if the arguments are followed by the correct number of values
• Readable array to get values for all or single parameters
• Partially usage message which you can show in your help

It should cover all common use cases, but some corner cases may not be covered, yet.

Feel free to open an issue if you find yourself in need of a missing feature, if you have an idea to simplify its usage or if you have an idea to improve the lib in gereral.

Motivation

Instead of using a bash script generator or similar tools, I like to interact with something that adapts with my needs while I am writing a script. Bash generators are a good thing to have when you know which parameters are needed and that those don't change, but you have to rerun them or edit the boilerplate if something changes. This small library takes a different approach with a minimal boilerplate in your script. By defining your script inputs as a datastructure (e.g. an associative array or an text matrix), all the boilerplate is generated from that datastructure. Therefore, your datastructure is the source of truth and the library adapts to it.

Requirements

• coreutils (cat, dirname, echo, printf, tr)
• gnu grep
• gnu sed

Run the template script

If you have nix and nix-shell installed on your system, you can run the scripts directly using:

./template.sh

If you don’t have nix-shell on your system, you have to take care of the needed dependencies and run it explicitly using bash, e.g.

bash ./template.sh

Namings

Some definitions:

name	description
input	parameter or argument for the script
parameter	short or long provided input, e.g. --name or -n
value / argument	argument for a parameter

Example: myscript.sh -f <filename> --enable-logs <foo> <bar>

• myscript.sh is the name of the script
• -f, <filename>, --enable-logs, <foo> and <bar> are all inputs
• -f is a named parameter followed by its value <filename>
• --enable-logs is a flag parameter
• <foo> and <bar> are unamed parameters

Parameter types

type (tpe)	can be optional?	arity	description
named	yes	n	named parameter followed by value, e.g. --named <value>
anonym	no	1	value without no preceeding parameter
flag	always	0	single flag to toggle inputs, e.g. --my-flag

Related

This project was created in companion with nix-cloud-scripts, a collection of scripts to ease your work with cloud environments.