[](https://travis-ci.org/kvz/bash3boilerplate) [This document is formatted with GitHub-Flavored Markdown. ]:# [For better viewing, including hyperlinks, read it online at ]:# [https://github.com/kvz/bash3boilerplate/blob/master/README.md]:# * [Overview](#overview) * [Goals](#goals) * [Features](#features) * [Installation](#installation) * [Changelog](#changelog) * [Best Practices](#best-practices) * [Frequently Asked Questions](#frequently-asked-questions) * [Authors](#authors) * [License](#license) ## Overview When hacking up Bash scripts, there are often higher level things like logging, configuration, command-line argument parsing that: - You need every time - Come with a number of pitfalls to avoid - 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 scripts. ## Goals Delete-Key-**Friendly**. We propose using [`main.sh`](https://github.com/kvz/bash3boilerplate/blob/master/main.sh) as a base and removing the parts you don't need, rather than introducing packages, includes, compilers, etc. This may feel a bit archaic at first, but that is exactly the strength of Bash scripts that we want to embrace. **Portable**. We're targeting Bash 3 (OSX still ships with 3 for instance). If you're going to ask people to install Bash 4 first, you might as well pick a more advanced language as a dependency. We're automatically testing BASH3 Boilerplate and it's proven to work on: - [Linux](https://travis-ci.org/kvz/bash3boilerplate/jobs/109804166#L91) `GNU bash, version 4.2.25(1)-release (x86_64-pc-linux-gnu)` - [OSX](https://travis-ci.org/kvz/bash3boilerplate/jobs/109804167#L2453) `GNU bash, version 3.2.51(1)-release (x86_64-apple-darwin13)` ## Features - Conventions so that after a while, all your scripts will follow the same, battle-tested structure - Safe by default (break on error, pipefail, etc) - Configuration by environment variables - Simple command-line argument parsing that requires no external dependencies. Definitions are parsed from help info, so there is no duplication - Helpful magic variables like `__file`, `__dir`, and `__os` - Logging that supports colors and is compatible with [Syslog Severity levels](http://en.wikipedia.org/wiki/Syslog#Severity_levels) as well as the [twelve-factor](http://12factor.net/) guidelines ## Installation There are 3 different ways you can install b3bp: ### option 1: Download the main template Use curl or wget to download the source, save as your script, and start deleting the unwanted bits, and adding your own logic. ```bash wget https://raw.githubusercontent.com/kvz/bash3boilerplate/master/main.sh vim main.sh ``` ### option 2: Clone the entire project Besides `main.sh`, this will get you the entire b3bp repository including a few extra functions that we keep in the `./src` directory. ```bash git clone git@github.com:kvz/bash3boilerplate.git ``` ### option 3: Require via npm As of `v1.0.3`, b3bp can also be installed as a node module so you define it as a dependency in `package.json` via: ```bash npm init npm install --save --save-exact bash3boilerplate ``` Although this last option introduces a Node.js dependency, this does allow for easy version pinning and distribution in environments that already have this prerequisite. But this is optional and nothing prevents you from just using `curl` and keep your project or build system low on external dependencies. ## Changelog Please see the [CHANGELOG.md](./CHANGELOG.md) file. ## Best practices As of `v1.0.3`, b3bp adds some nice re-usable libraries in `./src`. In order to make the snippets in `./src` more useful, we recommend these guidelines. ### Library exports It's nice to have a bash package that can be used in the terminal and also be invoked as a command line function. To achieve this the exporting of your functionality *should* follow this pattern: ```bash if [ "${BASH_SOURCE[0]}" != ${0} ]; then export -f my_script else my_script "${@}" exit $? fi ``` This allows a user to `source` your script or invoke as a script. ```bash # Running as a script $ ./my_script.sh some args --blah # Sourcing the script $ source my_script.sh $ my_script some more args --blah ``` (taken from the [bpkg](https://raw.githubusercontent.com/bpkg/bpkg/master/README.md) project) ### Miscellaneous - In functions, use `local` before every variable declaration - This project settles on two spaces for tabs - Use `UPPERCASE_VARS` to indicate environment variables that can be controlled outside your script - Use `__double_underscore_prefixed_vars` to indicate global variables that are solely controlled inside your script, with the exception of arguments wich are already prefixed with `arg_`, and functions, over which b3bp poses no restrictions. ## Frequently Asked Questions Please see the [FAQ.md](./FAQ.md) file. ## Authors - [Kevin van Zonneveld](http://kvz.io) - [Izaak Beekman](https://izaakbeekman.com/) - [Alexander Rathai](mailto:) - [Dr. Damian Rouson](http://www.sourceryinstitute.org/) (documentation, feedback) - [@jokajak](https://github.com/jokajak) (documentation) - [Gabriel A. Devenyi](http://staticwave.ca/) (feedback) - [@bravo-kernel](https://github.com/bravo-kernel) (feedback) ## License Copyright (c) 2013 Kevin van Zonneveld and [contributors](https://github.com/kvz/bash3boilerplate#authors). Licensed under [MIT](https://raw.githubusercontent.com/kvz/bash3boilerplate/master/LICENSE). You are not obligated to bundle the LICENSE file with your b3bp projects as long as you leave these references intact.