Prompts

Table of Contents

Click to expand Table of Contents

• Table of Contents
• Prompt handlers
• Logging to the shell
  • Transient log
  • Classic prompt log
  • Demo

Readline supports most of the prompts offered by Oh-My-Posh, namely:

• $PS1 - the primary prompt.
• $PS2 - the secondary prompt.
• RPROMPT - The right prompt, (which is not to be confused with a right-aligned primary prompt)
• Tooltip - A prompt being refreshed at every key input in the line (check [here] for an example).
• Transient - A prompt being printed in place of PS1 after command/line execution.

Additionally, readline supports those prompts for any valid oh-my-posh configuration.

Prompt handlers

The following functions are available to bind prompt handlers.

func (p *prompt) Primary(prompt func() string)
func (p *prompt) Right(prompt func() string)
func (p *prompt) Secondary(prompt func() string)
func (p *prompt) Transient(prompt func() string)
func (p *prompt) Tooltip(prompt func(tip string) string)

An extract of the console library previously mentioned above uses them like this:

func (prompt *Prompt) bind(shell *readline.Shell) {
    
    // The oh-my-posh prompt engine, with a loaded configuration. 
    p := prompt.Engine
        
    shell.Prompt.Primary(p.PrintPrimary)
    shell.Prompt.Right(p.PrintRPrompt)

    // Secondary prompt.
    secondary := func() string {
        return p.PrintExtraPrompt(engine.Secondary)
    }
    shell.Prompt.Secondary(secondary)

    // Transient prompt (never nil, but enabled with the readline configuration file)
    transient := func() string {
        return p.PrintExtraPrompt(engine.Transient)
    }
    shell.Prompt.Transient(transient)

    shell.Prompt.Tooltip(p.PrintTooltip)
}

Logging to the shell

The shell offers two methods to print output with different behavior.

Transient log

The first method will actually "push" the prompt below a log line to be printed. In detail, the current prompt/line/helpers are cleared, the log output is printed, and the prompt/line is redisplayed below it.

func (rl *Shell) TransientPrintf(msg string, args ...any)

Classic prompt log

There may be some cases, though, where you want the current prompt to be left as is, your log event to be printed below it, and a new prompt/input line to be displayed below. For this, the following method is given:

func (rl *Shell) Printf(msg string, args ...any)

Demo

The following shows a ticker printing 6 notification messages: the first 5 with the LogTransient() function, and the last one with Log().