/PSReadLine

A bash inspired readline implementation for PowerShell

Primary LanguageC#

PSReadLine

This module replaces the command line editing experience in PowerShell.exe. It provides:

  • Syntax coloring
  • Simple syntax error notification
  • A better multi-line experience (both editing and history)
  • Customizable key bindings
  • Cmd and emacs modes (neither are fully implemented yet, but both are usable)
  • Many configuration options
  • Bash style completion (optional in Cmd mode, default in Emacs mode)
  • Bash/zsh style interactive history search (CTRL-R)
  • Emacs yank/kill ring
  • PowerShell token based "word" movement and kill
  • Undo/redo

Many planned features are not yet implemented, but in it's current state, the module is very usable.

The "out of box" experience is meant to be very familiar to PowerShell.exe users - there should be no need to learn any new key strokes.

Keith Hill wrote a great introduction to PSReadline here: http://rkeithhill.wordpress.com/2013/10/18/psreadline-a-better-line-editing-experience-for-the-powershell-console/

Installation

First, you need to download the module. Using PsGet (http://psget.net, very easy to install), you can run:

install-module PSReadline

Alternatively, download the file https://github.com/lzybkr/PSReadLine/releases/download/Latest/PSReadline.zip and extract the contents into your C:\Users\[User]\Documents\WindowsPowerShell\modules\PSReadline folder. (You may have to create these directories if they don't exist)

Next edit your profile to import the module. There are two common profile files commonly used and the instructions are slightly different for each.

The file C:\Users\[User]\Documents\WindowsPowerShell\profile.ps1 is used for all hosts (e.g. the ISE and powershell.exe). If you already have this file, then you should add the following:

if ($host.Name -eq 'ConsoleHost')
{
    Import-Module PSReadline
}

Alternatively, the file C:\Users\[User]\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1 is for powershell.exe only. Using this file, you can simply add:

Import-Module PSReadLine  

In either case, you can create the appropriate file if you don't already have one.

Upgrading

If you installed with PSGet you can run Update-Module PSReadLine.

If you've added it to your $PROFILE, when you run Update-Module PSReadLine you will get the following error

Remove-Item : Cannot remove item
C:\Users\{yourName}\Documents\WindowsPowerShell\Modules\PSReadLine\PSReadline.dll: Access to the path
'C:\Users\{yourName}\Documents\WindowsPowerShell\Modules\PSReadLine\PSReadline.dll' is denied.
At C:\Users\{yourName}\Documents\WindowsPowerShell\Modules\PsGet\PsGet.psm1:1009 char:52
  1. Run cmd.exe
  2. powershell -noprofile
  3. Update-Module PSReadLine

Usage

To start using, just import the module:

Import-Module PSReadLine

To use Emacs key bindings, you can use:

Set-PSReadlineOption -EditMode Emacs

To view the current key bindings:

Get-PSReadlineKeyHandler

There are many configuration options, see the options to Set-PSReadlineOption. PSReadline has help for it's cmdlets as well as an about_PSReadline topic - see those topics for more detailed help.

To set your own custom keybindings, use the cmdlet Set-PSReadlineKeyHandler. For example, for a better history experience, try:

Set-PSReadlineKeyHandler -Key UpArrow -Function HistorySearchBackward
Set-PSReadlineKeyHandler -Key DownArrow -Function HistorySearchForward

With these bindings, up arrow/down arrow will work like PowerShell/cmd if the current command line is blank. If you've entered some text though, it will search the history for commands that start with the currently entered text.

To enable bash style completion without using Emacs mode, you can use:

Set-PSReadlineKeyHandler -Key Tab -Function Complete

Here is a more interesting example of what is possible:

Set-PSReadlineKeyHandler -Chord 'Oem7','Shift+Oem7' `
                         -BriefDescription SmartInsertQuote `
                         -LongDescription "Insert paired quotes if not already on a quote" `
                         -ScriptBlock {
    param($key, $arg)

    $line = $null
    $cursor = $null
    [PSConsoleUtilities.PSConsoleReadline]::GetBufferState([ref]$line, [ref]$cursor)

    if ($line[$cursor] -eq $key.KeyChar) {
        # Just move the cursor
        [PSConsoleUtilities.PSConsoleReadline]::SetCursorPosition($cursor + 1)
    }
    else {
        # Insert matching quotes, move cursor to be in between the quotes
        [PSConsoleUtilities.PSConsoleReadline]::Insert("$($key.KeyChar)" * 2)
        [PSConsoleUtilities.PSConsoleReadline]::GetBufferState([ref]$line, [ref]$cursor)
        [PSConsoleUtilities.PSConsoleReadline]::SetCursorPosition($cursor - 1)
    }
}

In this example, when you type a single quote or double quote, there are two things that can happen. If the character following the cursor is not the quote typed, then a matched pair of quotes is inserted and the cursor is placed inside the the matched quotes. If the character following the cursor is the quote typed, the cursor is simply moved past the quote without inserting anything. If you use Resharper or another smart editor, this experience will be familiar.

Note that with the handler written this way, it correctly handles Undo - both quotes will be undone with one undo.

See the public methods of [PSConsoleUtilities.PSConsoleReadLine] to see what other built-in functionality you can modify.

If you want to change the command line in some unimplmented way in your custom key binding, you can use the methods:

    [PSConsoleUtilities.PSConsoleReadLine]::GetBufferState
    [PSConsoleUtilities.PSConsoleReadLine]::Insert
    [PSConsoleUtilities.PSConsoleReadLine]::Replace
    [PSConsoleUtilities.PSConsoleReadLine]::SetCursorPosition