How can I change the PowerShell prompt to show just the parent directory and current directory?

Question

I would like to shorten my PowerShell prompt so that it just shows the parent directory and the current directory. For example, if the pwd is

C:\Users\ndunn\OneDrive\Documents\Webucator\ClassFiles\python-basics\Demos

I want the prompt to be:

PS ..\python-basics\Demos> 

I can get it to be just PS ..\Demos> by changing the prompt() function in the Profile file:

1. Find location of Profile file by running $profile in PowerShell.
2. Open (or create and open) Profile file.
3. Change (or add) the following prompt() function:

---

function prompt
{
  $folder = "$( ( get-item $pwd ).Name )"
  "PS ..\$folder> "
}

---

I tried using split() and negative indexing, but wasn't able to get it to work.

Also, I only want to do this if the pwd is at least two levels down. If the pwd is something like C:\folder\folder, I'd like to show the default prompt.

Any ideas?

Answer 1

Try the following function, which should work on Windows and Unix-like platforms (in PowerShell Core) alike:

function global:prompt {
  $dirSep = [IO.Path]::DirectorySeparatorChar
  $pathComponents = $PWD.Path.Split($dirSep)
  $displayPath = if ($pathComponents.Count -le 3) {
    $PWD.Path
  } else {
    '…{0}{1}' -f $dirSep, ($pathComponents[-2,-1] -join $dirSep)
  }
  "PS {0}$('>' * ($nestedPromptLevel + 1)) " -f $displayPath
}

Note that I've chosen single character … (HORIZONTAL ELLIPSIS, U+2026) to represent the omitted part of the path, because .. could be confused with referring to the parent directory.

Note: The non-ASCII-range … character is only properly recognized if the enclosing script file - assumed to be your $PROFILE file - is either saved as UTF-8 with BOM^[1] or as UTF-16LE ("Unicode").

If, for some reason, that doesn't work for you, use three distinct periods ('...' instead of '…'), though note that that will result in a longer prompt.

---

^{[1] The BOM is only a necessity in Windows PowerShell; by contrast, PowerShell Core assumes UTF-8 by default, so no BOM is needed.}