# A Prompt in Your Colors

The prompt is the text in a variable, PS1, so you choose what it shows with codes such as \\W for the folder and \\A for the time, color it with \\\[\\e\[…m\\\] codes, show the Git branch with \_\_git_ps1, and keep it in ~/.bashrc.

Journeyman · Unix · Linux · Updated November 10, 2026

## After this lesson you can

- Set PS1 with codes such as \\w, \\W, \\u, \\A and \\$ to choose what the prompt shows, and keep it in ~/.bashrc
- Color parts of the prompt with \\\[\\e\[…m\\\] codes, and show the Git branch with \_\_git_ps1

## Key takeaways

- The prompt is a variable, PS1. Its codes are filled in each time it's drawn, such as \u for the user, \w for the folder's path, \W for its name and \$ for the $.
- A color is a code such as \e[1;36m (bold cyan), and \e[0m sets the color back to normal. Wrap each code in \[ and \] so bash knows it takes up no room.
- $(__git_ps1 " (%s)") in PS1 shows the Git branch inside a Git project, and nothing anywhere else.
- A new PS1 lasts until the terminal closes. Add it to the end of ~/.bashrc to keep it. A Mac's zsh uses PROMPT, with codes of its own.

You look at the prompt more often than at any other line on your screen. Ubuntu's, something like `sam@laptop:~/terminal-practice/shortcuts$`, grows with every folder you go into, until your command starts halfway across the window. A web developer wants the prompt to say which Git branch they're on before they save work to the wrong one. An administrator makes the prompt on a server red, so they never mistake it for their own laptop. And it's yours: you choose what it shows and what colors it wears.

Everything in this lesson lasts only until you close the terminal, so experiment freely. A new terminal brings back the prompt you had.

## The prompt is a variable: PS1

When bash is ready for a command, it prints the value of a variable named `PS1` (read "P S 1", for *prompt string 1*). Here's Ubuntu's:

```bash
echo "$PS1"
```

```text
\[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$
```

It's a jumble, but you can spot pieces of the prompt you know: `\u@\h`, a colon, `\w`, and `\$`. Each code that starts with a backslash is filled in every time the prompt is drawn. You don't need to understand all of it, because you're about to write your own from scratch.

## Choose what it shows

| Code | Shows |
|---|---|
| `\u` | your user name |
| `\h` | the computer's name |
| `\w` | the folder you're in, as a whole path, with `~` for home |
| `\W` | only the folder's own name |
| `\A` | the time, as hours and minutes |
| `\t` | the time, with seconds |
| `\n` | a new line |
| `\$` | a `$`, or a `#` when you're the administrator |

Go into the practice folder from *Aliases and Small Functions*, and set a new `PS1`. Single quotes keep the backslashes as they are:

```bash
cd ~/terminal-practice/shortcuts
PS1='\w \$ '
```

The new prompt appears as soon as you press Enter. Here's a run of a few more, each typed at the prompt the one before it made:

```text
~/terminal-practice/shortcuts $ PS1='\W \$ '
shortcuts $ PS1='\u in \W \$ '
sam in shortcuts $ PS1='[\A] \W \$ '
[05:24] shortcuts $ PS1='\W\n\$ '
shortcuts
$
```

The last one puts the folder on a line of its own, so your command always starts at the left edge, however deep the folder.

## Colors

A color is a code the terminal reads instead of printing. `\e[` (read "escape, bracket") starts it, then come numbers and an `m`: `\e[1;36m` means bold cyan, and `\e[0m` means back to normal. These are **ANSI escape codes**, and nearly every terminal understands them.

| Number | 31 | 32 | 33 | 34 | 35 | 36 | 37 |
|---|---|---|---|---|---|---|---|
| Color | red | green | yellow | blue | magenta | cyan | white |

Each code goes inside `\[` and `\]`. They tell bash "this part takes up no room on the screen", so it knows how wide the prompt really is. Leave them out, and a long command wraps back over its own start. Here's the folder's name in bold cyan:

```bash
PS1='\[\e[1;36m\]\W\[\e[0m\] \$ '
```

![The prompt setting PS1 split into its five parts, each joined to what it does: the first color code turns bold cyan on, backslash W prints the folder's name, the second color code turns the color off, and the space and backslash dollar print " $ ", making the prompt "shortcuts $" with shortcuts in bold cyan](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/11/4f7f747b38e047d6b156a0083ff64986.webp)

![Ubuntu's terminal with the new prompt: the word shortcuts in bold cyan, then a white $ and the cursor](https://www.ask-codey.com/lessons/TODO)

Ubuntu's own prompt is in color too: `\033[01;32m` is its green and `01;34` its blue. `\033` is another way to write `\e`.

## The Git branch

Software projects are often kept in Git, where a **branch** is one line of work, such as `new-menu` beside `main`. Git comes with a function, `__git_ps1` (two underscores in front), that prints the branch you're on, and Ubuntu loads it into every terminal. Try it in a practice project. (If `git --version` says command not found, *Installing Tools: Homebrew and apt* installs Git; come back after it.)

```bash
mkdir -p ~/terminal-practice/my-site && cd ~/terminal-practice/my-site
git init -q -b main
PS1='\W$(__git_ps1 " (%s)") \$ '
```

`git init` makes the folder a Git project, with a branch named `main`. `$( )` (read "the output of") runs the command inside it each time the prompt is drawn, and puts what it prints in its place; Module 5 uses it a lot. In `" (%s)"`, `%s` stands for the branch's name. Now make a branch, and leave the project:

```text
my-site (main) $ git switch -c new-menu
Switched to a new branch 'new-menu'
my-site (new-menu) $ cd ..
terminal-practice $
```

Outside a Git project, `__git_ps1` prints nothing at all. On a system that doesn't load `__git_ps1` for you, the prompt complains that it can't find it; put `$(git branch --show-current 2>/dev/null)` in its place, which asks Git for the branch's name and throws away the error outside a project.

## Keep it, and zsh on a Mac

To keep a prompt, add its line to the end of `~/.bashrc`, after a backup copy, as in *Startup Files: .bashrc, .zshrc and source*. Ubuntu sets its own `PS1` higher up in the file, so yours, at the end, wins. This line combines the color and the branch:

```bash
PS1='\[\e[1;36m\]\W\[\e[0m\]$(__git_ps1 " (%s)") \$ '
```

**On a Mac**, zsh's prompt is `PROMPT`, with `%` codes: `%n` the user, `%~` the path, `%1~` the folder's name, `%T` the time, `%#` the `%` sign, and `%F{cyan}` to `%f` for a color. `setopt PROMPT_SUBST` lets it run `$( )`. These two lines go in `~/.zshrc`:

```bash
setopt PROMPT_SUBST
PROMPT='%F{cyan}%1~%f $(git branch --show-current 2>/dev/null) %# '
```

## Check yourself

2 questions to try on the lesson page.

## So what

The line you see most is now one you designed: the folder you care about, the branch you're on and colors you like, ready every time you open a terminal.

## Key terms

- [PS1](https://www.ask-codey.com/glossary/ps1)
- [Command Prompt](https://www.ask-codey.com/glossary/command-prompt)
- [ANSI Escape Code](https://www.ask-codey.com/glossary/ansi-escape-code)
- Current branch

## Cheat sheets

- [A Prompt in Your Colors](https://www.ask-codey.com/cheat-sheets/bash-custom-prompt-cheat-sheet)

## Related

- [Startup Files: .bashrc, .zshrc and source](https://www.ask-codey.com/lessons/bash-startup-files)
- [Aliases and Small Functions](https://www.ask-codey.com/lessons/bash-aliases-and-small-functions)

Source: https://www.ask-codey.com/lessons/bash-custom-prompt