Powershell如何在按键上进行快速更改？

Question

I'm new to Powershell. I'm trying to create my own custom prompt that shows a truncated version of the current dir unless you expand it by pressing CTRL + R . Moreover, I would like to do this:

$short\dir\path...>
*user presses CTRL+R*
$really\really\long\full\dir\path>
*Full dir path is shown as long as CTLR + R is held down*

Answer 1

This isn't a super elegant solution, but it basically turns Ctrl + Alt + R into a hotkey for displaying the current directory. You can change the chord to "Ctrl+R" but you'll be overwriting a default PSReadlineKeyHandler for powershell. It looks like it gets stuck on the command, but if you begin typing the next line will appear. You will need to add both of these to your Microsoft.Powershell_Profile.ps1 located in $env:USERPROFILE\\Documents\\WindowsPowershell\\

function prompt {
    if(($pwd | split-path -Parent | Split-Path -Leaf) -match ':')
    {
        "$pwd\>"
    }
    elseif (($pwd | Split-Path -Leaf) -match ':')
    {
        "$pwd>"
    }
    else {
        "...\$($pwd | split-path -Parent | Split-Path -Leaf)\$($pwd | Split-path -Leaf)\>"
    }
}

Set-PSReadlineKeyHandler -Chord "Ctrl+Alt+R" -ScriptBlock {
    write-host $pwd -nonewLine
}

Hopefully that helps!

Answer 2

I don't think there is a way to do that, but I can share with you a custom prompt I like to use instead:

function prompt {
    $Host.UI.RawUI.WindowTitle = Get-Location
    "[$env:COMPUTERNAME] PS> "
}

This puts the current computer name in the prompt (you may have no need for this), but puts the current path in the window title, where long paths especially are out of the way and don't clutter the prompt.

Answer 3

The following is a way to do this, but it involves a lot of compromises. First it only while work in the PS console, not the ISE, or not in any application that hosts PS. Second it will involve a lot of work, depending on how, ummm, "smooth" you want the experience to be. Third, it'll probably cause other unexpected stuff to happen.

Basically you write a script for the prompt function that polls the keyboard looking either for Ctrl-R or any other "action" character. By "action" character I mean something like enter, tab, backspace, up-arrow, down-arrow, etc. that causes something to happen. If the script sees Ctrl-R then you can output the full path, either in the title bar, or to the console. If you output it to the console, then your script will have to figure out which row of the console contains the current prompt. The Rawui member contains this info.

A bare outline might look like:

  do {
    sleep -milli 250
    if ($host.ui.rawui.keyavailable) {
      $key = $host.ui.rawui.readkey()
      if ($key.character -eq [char]'x') {
        write-host burp
      } else { break}
    }
  } while ($true)

Every quarter second the script sees if a key is available. If so it reads the key. If the key is 'x' (ctrl-r for you) it outputs "burp". But you'd change 'burp' to the full path, along with logic to put the message in the right place (title bar or the right row on the console).

If the key isn't 'x' then this simple example just returns. That means the 'x' gets "eaten" and the 'x' functionality no longer works until the next prompt is output. However you could instead handle all of the "action" keys yourself instead of returning. If up-arrow is pressed you'd retrieve the previous command and output it to the console. If backarrow is pressed you'd delete the character before the cursor. If tab is pressed you'd have to interact with PS' built-in command completion (not sure if that's possible). Etc.

Eventually when the user presses return, you'd need to either feed all the keys that make up the command line to the console (you can use the SendKeys method of the WScript host), or you can execute the command directly from you prompt function, using Invoke-Expression (iex). If you use iex the command history that PS keeps (ie get-history) won't work, unless you figure out a way to handle that (maybe Add-History?). If you use SendKeys there's a chance that someone typing fast will get his key strokes interspersed with SendKeys.

As a compromise, instead of handling all the "action" keys yourself, you could just exit the prompt when a key besides ctrl-r is pressed and use SendKeys to send that one key to the console, to prevent the char from getting "eaten". That way you could probably get by with 20 lines of script instead of a few hundred, at the expense of ctrl-r only working before any characters are typed.

Another complication. readkey() does allow you to get both down and up keystrokes. So you could display the full path as long as the 'r' in ctrl-r is pressed. However your script would need to understand up/down keystrokes elsewhere. That might be as simple as just ignoring the down keystrokes.

There is one bright side to this. You could implement key-handling functionality over and above what PS normally does. So if you wanted ctrl-t to show the current time, you could do that. If you wanted ctrl-w to delete the current word under the cursor you could.