@@ -33,25 +33,26 @@ You can go to this distribution website and have a look at the list of firms usi
A command-line interpreter (or shell), is a software designed to read lines of text entered by a user to interact with an OS.
To simplify the shell executes the following infinite loop:
1. read a line
2. translate this line as a program execution with its parameters
3. launch the corresponding program with the parameters
3. wait for the program to finish
4. Go back to 1.
When you open a terminal on an Unix-like OS, you will have a **prompt** displayed: it can end with a **$** or a **%** character depending on your configuration. As long as you see your prompt, it means that you are in step **1.**, if no prompt is visible, you are in step **4.** or you have set up a very minimalist configuration for your shell.
When you open a terminal on an Unix-like OS, you will have a **prompt** displayed: it can end with a `$` or a `%` character depending on your configuration. As long as you see your prompt, it means that you are in step **1.**, if no prompt is visible, you are in step **4.** or you have set up a very minimalist configuration for your shell.
The blinking square or vertical bar represents your **cursor**. Shell predates graphical interfaces, so most of the time you won’t be able to move this cursor with your mouse, but with the directional arrows (left and right).
The blinking square or vertical bar represents your **cursor**. Shell predates graphical interfaces, so most of the time you won’t be able to move this cursor with your mouse, but with the **directional arrows** (left and right).
On the IFB, your prompt is a **$**
On the IFB, your prompt is a `$`:
```sh
etudiant@VM:~$
```
You can identify the following information from your prompt: **etudiant** is your login and **VM** is the name of your VM (**~** is where you are on the computer, but we will come back to that later).
You can identify the following information from your prompt: **etudiant** is your login and **VM** is the name of your VM (`~` is where you are on the computer, i.e. the current working directory, but we will come back to that later).
On Ubuntu 20.04, the default shell is [Bash](https://en.wikipedia.org/wiki/Bash_(Unix_shell)) while on recent version of macOS it’s [zsh](https://en.wikipedia.org/wiki/Z_shell). There are [many different shell](https://en.wikipedia.org/wiki/List_of_command-line_interpreters), for example, Ubuntu 20.04 also has [sh](https://en.wikipedia.org/wiki/Bourne_shell) installed.
