Bash Prompts¶

This is a collection of functions to give you control over how prompts are displayed in Bash. The Bash Shell provides 4 levels of prompt: $PS1, $PS2, $PS3, and $PS4. Each of these functions affects only a single prompt level. So you’re free to mix and match them as you like. Prompt levels one and two are easy enough to trigger from the command line. Levels three and four are best demonstrated within a script. So test scripts have been provided in the ~/opal/bash/ directory, which are named ps3-example.bash and ps4-example.bash respectively.

There was considered effort to provide few different prompt styles provided, to anticipate the needs of most people. However, should you find that you want something different, you can make your own prompt functions. You can copy the desired Opal function. Just remember to use your own namespace.

PS1: The Primary Prompt¶

PS1 is an environment variable that holds the value of your primary prompt. This is the primary prompt that you interact with on the command line. It’s the most most visible of the 4 prompts that Bash provides. In fact, many people tend to forget that they can customize the other prompts.

opal:ps1_brief¶

This style of prompt is quite common. It shows the username, name, and the base directory. The home directory is displayed as a ~ (tilde). If you’re a Git user, the branch name is also included after the directory. There’s a design assumption that a dark terminal theme is being used when color is passed as an argument. The default is to use text formatting like bold or underline .

@param style Optional.: The value color is currently the only option.

username@host ~ $

opal:ps1_brief_light¶

This is the light theme companion to opal:ps1_brief. The structure is the same.

username@host ~ $

opal:ps1_default_dark¶

This style of prompt uses two lines. Most people use a single user account on a single machine. Due to this idea, the username and hostname are not included in the prompt. The prompt starts with the time in 24-hour format. This is followed by the base directory name. A ~ (tilde) will be used to represent the home directory. This relies upon a dark terminal theme being used. The final piece of data is the history number.

On the second line, there is only the $ (dollar symbol) which shows that you’re a normal user. This will be changed to a # if you’re root. The nice this about this style of prompt, is that it provides some detail about your session, while providing a lot of space for you to write your command.

13:00:34> directory-name> 849>
$

opal:ps1_default_light¶

This is the light theme companion to opal:ps1_default_dark. The structure is the same.

13:00:34> directory-name> 849>
$

opal:ps1_developer¶

This prompt provides the most information to the user. Sometimes a git branch name can be quite long. With that in mind, this prompt style displays the current git branch on the top line when available. The second line displays the common username@hostname pattern. The third line displays the current date and time using the opal-datetime format, followed by the directory base name.

git-branch-name
useranme@hostname
2026 Apr 30 Thu 16:24 directory-name
$

opal:ps1_developer_light¶

git-branch-name
useranme@hostname
2026 Apr 30 Thu 16:24 directory-name
$

opal:ps1_minimal¶

A minimal prompt that shows the current working directory with $HOME abbreviated with a tilde. The history number of this command is shown for ease of command reuse. The $ symbol is used to reflect you’re a normal user, where the # is used for root.

The username and hostname are not shown in this prompt because the most common use case is for a person to always use their personal account on their own machine. Also the git branch is not used in this prompt.

dirname 842:$>

PS2: The Continuation Prompt¶

Unofficially, I call this the continuation prompt. This can be triggered when using the \ at the end of a line. If you open a string with a single or double quote, and press return, this will also trigger the continuation prompt. This tells Bash that you’re not done writing the current command. Bash will give you a new line to keep appending to the current command.

opal:ps2_default_dark¶

This prompt is designed to connect with opal:ps1_default_dark, so that it looks like a continuation of the PS1 command. So it’s purposefully minimal.

$ >

opal:ps2_default_light¶

This is the light theme companion to opal:ps2_default_dark.

$ >

PS3: The Selection Prompt¶

The selection prompt, which is used when presenting a list of choices.

opal:ps3_default¶

Choose a #>

opal:ps3_minimal¶

Select:

PS4: The Debug Prompt¶

The debug prompt, helps you understand what is happening when scripts run. It gets displayed when execution trace is enabled. Every line of the script is displayed to you, immediately before the line of code is about to execute. Then it executes, and displays the output. The amount of detail is in the prompt is up to you. Opal offers you three PS4 prompt styles.

opal:ps4_default¶

This prompt function tries to help you by vertically displaying of function name file, and line number for each line of the script executed.

source-file: path/to/example.bash
Function: your_function_name
Line: 54
>

opal:ps4_minimal¶

This prompt function tries to help you by displaying on a single chevron for each line of the script executed.

opal:ps4_simple¶

This prompt function tries to help you by displaying on a single line, the filename and line number for each line of the script executed.

path/to/example.bash:54>