There are many cases where using BASH to code ends up overcomplicating things. But due to it's portability (BASH is everywhere) there are plenty of cases where it makes sense to use BASH over other more dependcy-heavy languages.

When I do hack up a BASH script, I often find there are some higherlevel things like logging, configuration, commandline argument parsing that

• I need everytime
• take quite some effort to get right, and
• keep you from your actual work.

Here's an attempt to bundle those things in a generalized way so that they are reusable as-is in most of my (and hopefully your, if not ping me) programs.

Goals

I'm going to be pragmatic and violate good practices like DRY and the things I know about sourcing files, git submodules, package management, etc.

I feel that when a program consists of multiple files, BASH may very well not be the right tool for the job.

Copy-pasting, and removing what you don't need may not seem very rocket-scientific, or 2013, but in fact neither is BASH.

Keeping things simple, small and lightweight should be key here.

Aiming for portability I'm targetting BASH 3 (OSX still ships with v3 for instance). If you're going to ask people to install BASH 4 first, you might as well pick a better language as a dependency and code up your script in that.

The main template shoud only have features that are needed 80% of the time you write BASH.

Other cool functions can be adopted into this repository, but should not be referenced by the main.sh template and function purely as a resource.

Features

• Structure
• Configuration by environment variables
• Configuration by commandline arguments (definitions parsed from help info, so no duplication needed)
• Magic variables like FILE and DIR
• Logging that supports colors and is compatible with Syslog Severity levels

Conventions

It's the task of the script's caller to:

• redirect the output to appropriate locations
• correctly set the PATH variable (think cronjobs)

Recommendations

• using spaces vs tabs so you can copy-paste parts directly into the console, without BASH's automcomplete firing on every tab character
• using set -eu, so it will break on every error and undefined variable. if you're expecting an error, add ||true to your command.
• checkout The 10 Commandments of Logging

Notes

• use emergency to exit with 1

Compile

For those who want the template to get out of there way, I'm also shipping a compiled version that removes some comments, puts more things on one line, etc. For readability and boilerplate development, use the bigger version.

Fork

I'm looking forward to your comments and pull requests!

On github