Writing a program that will demo the $PS2 variable

Question

I've been customizing my terminal prompt, and found that it's possible to change the "secondary prompt". However, I have no way to test the changes I make to this one so I was wondering if a simple script could be written to test the new $PS2?

Answer 1

From man bash:

   PS2    The value of this parameter is expanded as with PS1 and used  as
          the secondary prompt string.  The default is ``> ''.

The "secondary prompt string" is what is shown when you have multi-line input. For example:

$ echo 'foo
>bar'

The > shown above is PS2. If I were to change that, I would see it as soon as I tried any multi-line command:

$ PS2="%"
$ echo 'foo
%bar'

Ways to run multi-line commands include:

• Open quotes (single or double) and hit enter without closing them.

• Add a backslash to the end of a command and hit enter:

  $ echo foo \
  >
  

• Use a HEREDOC:

  $ echo <<<END  ## hit enter
  

As for doing it with a script, that's really not needed but you can simply write a script that prints PS2:

#!/usr/bin/env bash
printf "PS2 : %s\n" "$PS2"