Unix shell / linux command line / bash

bash is the most common Linux shell, a command-line environment where you can enter and thus run commands interactively. You can find extensive resources about it online, and oftentimes searching for your particular problem online will provide suggestions for solutions.

Here are two quick-and-easy introductions that focus on the most important aspects and should be doable in a few hours:

• Unix Crash Course by Sean Barker (with xkcd comics;), and with some infos on server access on the command-line
• Unix Crash Course by csoft.net, with a bit more on file permissions

Here is a very well curated and more thorough introduction to the command line with a motivating example running through the course:

• Software Carpentry introduction to the Unix shell

And some additional material, for those who want to dive in deeper or skip ahead:

• Software Carpentry introductions to some Unix shell extras, for example including working remotely (ssh), variables, and awk

And here are some more detailed resources:

• Bash Guide for Beginners: Step-by-step introduction to some of the most important features.
• Advanced Bash-Scripting Guide: Extensive reference for (almost) all imaginable things in bash. For example, you can find a table of all string operations in bash.

bash scripts

You can write full scripts in plain text files, with one command per row and including flow controls (like if-else clauses) in bash, so that you can repeat any number of steps easily. This script can just contain commands, and if it is saved as path/to/some_script.bash, you could execute it with:

bash path/to/some_script.bash

Instead, you can also specify that it is a bash script within the file, by including the following first line in the file path/to/another_script.bash (if you are interested in what this line does, check out the explanation on stackoverflow):

#!/usr/bin/env bash

If you then make that file executable for your user with chmod u+x another_script.bash, you can execute it by simply calling the name:

path/to/another_script.bash

Your shell will know to use the bash from your main environment to execute this script.