Modules and Packages

An introduction to Murex modules and packages

Description

Murex has it's own module system with namespacing and a package manager. But why should a shell need all this?

The answer comes from years of me using Bash and wishing my Bash environment could be consistent across multiple machines. So this document is authored from the perspective of my personal usage ("me" being Laurence Morgan, the original author of Murex).

What Murex's package system provides is:

1. A way to ensure consistency across multiple platforms
2. An easy way to extend Murex
3. An easy way to share what you've extended with others
4. An easy way to ensure your extensions are kept up-to-date
5. An easy way to track what code is running in your shell and from where it was loaded

Before I address those points in more detail, a bit of background into what modules and packages are:

What Are Packages And Modules?

Murex comes with it's own package manager to make managing plugins easier.

The format of the packages is a directory, typically located at ~/.murex_modules, which contains one or more murex scripts. Each script can be it's own module. ie there are multiple modules that can be grouped together and distributed as a single package.

The way packages and modules are represented is as a path: package/module

murex-package is a package management tool for administrating murex modules and packages.

Name	Summary
https://github.com/lmorg/murex-module-jump	Enables autojump functionalities
https://github.com/orefalo/murex-module-starship	starship - The minimal, blazing-fast, and infinitely customizable prompt
and many more	Murex modules typically follow the murex-module-* naming convention

Using Packages And Modules

Consistency

Package database are stored locally at ~/.murex_modules/packages.json. This file is portable so any new machine can have packages.json imported. The easiest way of doing this is using murex-package which can import from a local path or HTTP(S) URI and automatically download any packages described in the database.

For example the command I run on any new dev machine to import all of my DevOps tools and terminal preferences is the following:

murex-package import https://gist.githubusercontent.com/lmorg/770c71786935b44ba6667eaa9d470888/raw/fb7b79d592672d90ecb733944e144d722f77fdee/packages.json

Extendability

Namespacing allows for private functions which allows you to write smaller functions. Smaller functions are easier to write tests against (Murex also has an inbuilt testing and debugging tools).

Sharing Code

Packages can be hosted via HTTP(S) or git. Anyone can import anyone elses packages using murex-package.

murex-package install https://github.com/lmorg/murex-module-murex-dev.git

Updating Packages

Updating packages is easy:

murex-package update

Tracking Code

All code loaded in Murex, every function, variable and event (etc) is stored in memory with metadata about where it was loaded from; which package, file and at what time. This is called FileRef.

For more information on FileRef see the link below.

Module Strings For Non-Module Code

Source

A common shell idiom is to load shell script files via source / .. When this is done the module string (as seen in the FileRef structures described above) will be source/hash where hash will be a unique hash of the file path and load time.

Thus no two sourced files will share the same module string. Even the same file but modified and sourced twice (before and after the edit) will have different module strings due to the load time being part of the hashed data.

REPL

Any functions, variables, events, auto-completions, etc created manually, directly, in the interactive shell will have a module string of murex and an empty Filename string.

See Also

• FileRef: How to track what code was loaded and from where
• murex-package: Murex's package manager
• private: Define a private function block
• source: Import Murex code from another file of code block
• test: Murex's test framework - define tests, run tests and debug shell scripts

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This document was generated from gen/user-guide/modules_doc.yaml.