Environment Inspector

This repository contains a Python 3 script to help with setting up packages which at some point in the install process source a shell script to set a lot of variables.

This allows you to:

Save the current environment state to a file.
Source the shell script (or whatever).
Compare the current environment with the file.

Saving the environment

$ python3 ei.py -a save -f old.env

Comparing old and new environments

$ python3 ei.py -a compare -f old.env

This will print out a python dictionary with the differences. More usefully you can use the -m flag to get more usable outputs.

mode	function
`dict`	prints a python dict (default)
`bash`	prints a script that will change from the old to new environment.
`bash_smart`	as `bash` but attempts to base modified enviroment variables on the original ones (`export PATH=/usr/bin:$PATH` etc.)
`module`	outputs in a format compatible with Environment Modules
`module_smart`	as `module` but attempts to base modified enviroment variables on the original ones.

When Python 3 gets in the way

Unfortunately sometimes you want to inspect environmental changes when having one of our Python 3 modules loaded will get in the way. To fix this, you can save the two environments to two different text files with env > somefilename and then use forensic mode to compare them.

e.g.

$ env > old_environment.txt

(source the .sh files that change the environment)

$ env > new_environment.txt
$ module load python/3.6.3
$ python3 ei.py -a forensic -f old_environment.txt -n new_environment.txt -m bash_smart

This will generate a bash script that takes the environment from the one in old_environment.txt to the one in new_environment.txt.