Dev 101: Shell in a nutshell

In the Dev 101 series I cover some basic concepts of computer programming for a broad audience. I guess it’s the explanation I was looking for myself, when I first started out as a programmer…

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In a previous installment of the Dev 101 series, I explained the concept of the shell — a command language interpreter that executes commands read from standard input, a command line string, or a specified file.

Dev 101: Terminal velocity

This means that shell can be used either interactively via the terminal:

tdeneire@XPS-13-9370:~$ sh
$ echo "hello"
hello
$ exit
tdeneire@XPS-13-9370:~$

or as a CLI:

sh -c "echo $(date)"

or to execute Shell scripts, saved as .shfiles like this:

#!/bin/sh
echo "Hello world"

You can then execute them with sh myfile.sh

Especially the last option is a fantastic tool for writing scripts for automation, installation, configuration, and so on.