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PSReadLine

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about_PSReadLine

SHORT DESCRIPTION

PSReadLine provides an improved command line editing experience in the PowerShell console.

LONG DESCRIPTION

PSReadLine provides a powerful command line editing experience for the PowerShell console. It provides:

  • Syntax coloring of the command line
  • A visual indication of syntax errors
  • A better multi-line experience (both editing and history)
  • Customizable key bindings
  • Cmd and Emacs modes
  • Many configuration options
  • Bash style completion (optional in Cmd mode, default in Emacs mode)
  • Emacs yank/kill ring
  • PowerShell token based "word" movement and kill

The following functions are available in the class [Microsoft.PowerShell.PSConsoleReadLine].

Cursor movement

EndOfLine

  • Cmd: <End>
  • Emacs: <End> or <Ctrl+E>

If the input has multiple lines, move to the end of the current line, or if already at the end of the line, move to the end of the input. If the input has a single line, move to the end of the input.

BeginningOfLine

  • Cmd: <Home>
  • Emacs: <Home> or <Ctrl+A>

If the input has multiple lines, move to the start of the current line, or if already at the start of the line, move to the start of the input. If the input has a single line, move to the start of the input.

NextLine

  • Cmd: unbound
  • Emacs: unbound

Move the cursor to the next line if the input has multiple lines.

PreviousLine

  • Cmd: unbound
  • Emacs: unbound

Move the cursor to the previous line if the input has multiple lines.

ForwardChar

  • Cmd: <RightArrow>
  • Emacs: <RightArrow> or <Ctrl+F>

Move the cursor one character to the right. This might move the cursor to the next line of multi-line input.

BackwardChar

  • Cmd: <LeftArrow>
  • Emacs: <LeftArrow> or <Ctrl+B>

Move the cursor one character to the left. This might move the cursor to the previous line of multi-line input.

ForwardWord

  • Cmd: unbound
  • Emacs: <Alt+F>

Move the cursor forward to the end of the current word, or if between words, to the end of the next word. You can set word delimiter characters with:

Set-PSReadLineOption -WordDelimiters `<string of delimiter characters>`

NextWord

  • Cmd: <Ctrl+RightArrow>
  • Emacs: unbound

Move the cursor forward to the start of the next word. You can set word delimiter characters with:

Set-PSReadLineOption -WordDelimiters `<string of delimiter characters>`

BackwardWord

  • Cmd: <Ctrl+LeftArrow>
  • Emacs: <Alt+B>

Move the cursor back to the start of the current word, or if between words, the start of the previous word. You can set word delimiter characters with:

Set-PSReadLineOption -WordDelimiters `<string of delimiter characters>`

ShellForwardWord

  • Cmd: unbound
  • Emacs: unbound

Like ForwardWord except word boundaries are defined by PowerShell token boundaries.

ShellNextWord

  • Cmd: unbound
  • Emacs: unbound

Like NextWord except word boundaries are defined by PowerShell token boundaries.

ShellBackwardWord

  • Cmd: unbound
  • Emacs: unbound

Like BackwardWord except word boundaries are defined by PowerShell token boundaries.

GotoBrace

  • Cmd: <Ctrl+}>
  • Emacs: unbound

Go to the matching parenthesis, curly brace, or square bracket.

AddLine

  • Cmd: <Shift-Enter>
  • Emacs: <Shift-Enter>

The continuation prompt is displayed on the next line and PSReadLine waits for keys to edit the current input. This is useful to enter multi-line input as a single command even when a single line is complete input by itself.

Basic editing

CancelLine

  • Cmd: unbound
  • Emacs: unbound

Cancel all editing to the line, leave the line of input on the screen but return from PSReadLine without executing the input.

RevertLine

  • Cmd: <ESC>
  • Emacs: <Alt+R>

Reverts all of the input since the last input was accepted and run. This is equivalent to using the Undo command until there is nothing left to undo.

BackwardDeleteChar

  • Cmd: <Backspace>
  • Emacs: <Backspace> or <Ctrl+H>

Delete the character before the cursor.

DeleteChar

  • Cmd: <Delete>
  • Emacs: <Delete>

Delete the character under the cursor.

DeleteCharOrExit

  • Cmd: unbound
  • Emacs: <Ctrl+D>

Like DeleteChar, unless the line is empty, in which case exit the process.

AcceptLine

  • Cmd: <Enter>
  • Emacs: <Enter> or <Ctrl+M>

Attempt to execute the current input. If the current input is incomplete (for example, there is a missing closing parenthesis, bracket, or quote), then the continuation prompt is displayed on the next line, and PSReadLine waits for keys to edit the current input.

AcceptAndGetNext

  • Cmd: unbound
  • Emacs: <Ctrl+O>

Like AcceptLine, but after the line completes, start editing the next line from history.

ValidateAndAcceptLine

  • Cmd: unbound
  • Emacs: unbound

Like AcceptLine but performs additional validation including:

  • Checks for additional parse errors
  • Validates that command names are all found
  • If you are running PowerShell 4.0 or newer, validates the parameters and arguments

If there are any errors, the error message is displayed and not accepted nor added to the history unless you either correct the command line or execute AcceptLine or ValidateAndAcceptLine again while the error message is displayed.

BackwardDeleteLine

  • Cmd: <Ctrl+Home>
  • Emacs: unbound

Delete the text from the start of the input to the cursor.

ForwardDeleteLine

  • Cmd: <Ctrl+End>
  • Emacs: unbound

Delete the text from the cursor to the end of the input.

SelectBackwardChar

  • Cmd: <Shift+LeftArrow>
  • Emacs: <Shift+LeftArrow>

Adjust the current selection to include the previous character.

SelectForwardChar

  • Cmd: <Shift+RightArrow>
  • Emacs: <Shift+RightArrow>

Adjust the current selection to include the next character.

SelectBackwardWord

  • Cmd: <Shift+Ctrl+LeftArrow>
  • Emacs: <Alt+Shift+B>

Adjust the current selection to include the previous word.

SelectForwardWord

  • Cmd: unbound
  • Emacs: <Alt+Shift+F>

Adjust the current selection to include the next word using ForwardWord.

SelectNextWord

  • Cmd: <Shift+Ctrl+RightArrow>
  • Emacs: unbound

Adjust the current selection to include the next word using NextWord.

SelectShellForwardWord

  • Cmd: unbound
  • Emacs: unbound

Adjust the current selection to include the next word using ShellForwardWord.

SelectShellNextWord

  • Cmd: unbound
  • Emacs: unbound

Adjust the current selection to include the next word using ShellNextWord.

SelectShellBackwardWord

  • Cmd: unbound
  • Emacs: unbound

Adjust the current selection to include the previous word using ShellBackwardWord.

SelectBackwardsLine

  • Cmd: <Shift+Home>
  • Emacs: <Shift+Home>

Adjust the current selection to include from the cursor to the start of the line.

SelectLine

  • Cmd: <Shift+End>
  • Emacs: <Shift+End>

Adjust the current selection to include from the cursor to the end of the line.

SelectAll

  • Cmd: <Ctrl+A>
  • Emacs: unbound

Select the entire line. Moves the cursor to the end of the line.

SelfInsert

  • Cmd: <a>, <b>, ...
  • Emacs: <a>, <b>, ...

Insert the key entered.

Redo

  • Cmd: <Ctrl+Y>
  • Emacs: unbound

Redo an insertion or deletion that was undone by Undo.

Undo

  • Cmd: <Ctrl+Z>
  • Emacs: <Ctrl+_>

Undo a previous insertion or deletion.

History

ClearHistory

  • Cmd: <Alt+F7>
  • Emacs: unbound

Clears history in PSReadLine. This does not affect PowerShell history.

PreviousHistory

  • Cmd: <UpArrow>
  • Emacs: <UpArrow> or <Ctrl+P>

Replace the current input with the previous item from PSReadLine history.

NextHistory

  • Cmd: <DownArrow>
  • Emacs: <DownArrow> or <Ctrl+N>

Replace the current input with the next item from PSReadLine history.

ForwardSearchHistory

  • Cmd: <Ctrl+S>
  • Emacs: <Ctrl+S>

Search forward from the current history line interactively.

ReverseSearchHistory

  • Cmd: <Ctrl+R>
  • Emacs: <Ctrl+R>

Search backward from the current history line interactively.

HistorySearchBackward

  • Cmd: <F8>
  • Emacs: unbound

Replace the current input with the previous item from PSReadLine history that matches the characters between the start and the input and the cursor.

HistorySearchForward

  • Cmd: <Shift+F8>
  • Emacs: unbound

Replace the current input with the next item from PSReadLine history that matches the characters between the start and the input and the cursor.

BeginningOfHistory

  • Cmd: unbound
  • Emacs: <Alt+<>

Replace the current input with the last item from PSReadLine history.

EndOfHistory

  • Cmd: unbound
  • Emacs: <Alt+>>

Replace the current input with the last item in PSReadLine history, which is the possibly empty input that was entered before any history commands.

Tab Completion

TabCompleteNext

  • Cmd: <Tab>
  • Emacs: unbound

Attempt to complete the text surrounding the cursor with the next available completion.

TabCompletePrevious

  • Cmd: <Shift-Tab>
  • Emacs: unbound

Attempt to complete the text surrounding the cursor with the next previous completion.

Complete

  • Cmd: unbound
  • Emacs: <Tab>

Attempt to perform completion on the text surrounding the cursor. If there are multiple possible completions, the longest unambiguous prefix is used for completion. If you are trying to complete the longest unambiguous completion, a list of possible completions is displayed.

  • Cmd: <Ctrl+Space>
  • Emacs: <Ctrl+Space>

Attempt to perform completion on the text surrounding the cursor. If there are multiple possible completions, a list of possible completions is displayed, and you can select the correct completion by using the arrow keys, or Tab/Shift+Tab. Escape and Ctrl+G cancel the menu selection, and revert the line to the state before invoking MenuComplete.

PossibleCompletions

  • Cmd: unbound
  • Emacs: <Alt+Equals>

Display the list of possible completions.

SetMark

  • Cmd: unbound
  • Emacs: <Alt+Space>

Mark the current location of the cursor for use in a subsequent editing command.

ExchangePointAndMark

  • Cmd: unbound
  • Emacs: <Ctrl+X,Ctrl+X>

The cursor is placed at the location of the mark and the mark is moved to the location of the cursor.

Kill/Yank

Kill and Yank operate on a clipboard in the PSReadLine module. There is a ring buffer called the kill ring - killed text is added to the kill ring up and yank will copy text from the most recent kill. YankPop cycles through items in the kill ring. When the kill ring is full, new items replace the oldest items. A kill operation that is immediately preceded by another kill operation appends the previous kill, instead of adding a new item or replacing an item in the kill ring. This is how you can cut a part of a line, for example, with multiple KillWord operations, then yank them back elsewhere as a single yank.

KillLine

  • Cmd: unbound
  • Emacs: <Ctrl+K>

Clear the input from the cursor to the end of the line. The cleared text is placed in the kill ring.

BackwardKillLine

  • Cmd: unbound
  • Emacs: <Ctrl+U> or <Ctrl+X,Backspace>

Clear the input from the start of the input to the cursor. The cleared text is placed in the kill ring.

KillWord

  • Cmd: unbound
  • Emacs: <Alt+D>

Clear the input from the cursor to the end of the current word. If the cursor is between words, the input is cleared from the cursor to the end of the next word. The cleared text is placed in the kill ring.

BackwardKillWord

  • Cmd: unbound
  • Emacs: <Alt+Backspace>

Clear the input from the start of the current word to the cursor. If the cursor is between words, the input is cleared from the start of the previous word to the cursor. The cleared text is placed in the kill ring.

ShellKillWord

  • Cmd: unbound
  • Emacs: unbound

Like KillWord, except word boundaries are defined by PowerShell token boundaries.

ShellBackwardKillWord

  • Cmd: unbound
  • Emacs: unbound

Like BackwardKillWord, except word boundaries are defined by PowerShell token boundaries.

UnixWordRubout

  • Cmd: unbound
  • Emacs: <Ctrl+W>

Like BackwardKillWord, except word boundaries are defined by white space.

KillRegion

  • Cmd: unbound
  • Emacs: unbound

Kill the text between the cursor and the mark.

Copy

  • Cmd: <Ctrl+Shift+C>
  • Emacs: unbound

Copy selected region to the system clipboard. If no region is selected, copy the whole line.

CopyOrCancelLine

  • Cmd: <Ctrl+C>
  • Emacs: <Ctrl+C>

Either copy selected text to the clipboard, or if no text is selected, cancel editing the line with CancelLine.

Cut

  • Cmd: <Ctrl+X>
  • Emacs: unbound

Delete selected region placing deleted text in the system clipboard.

Yank

  • Cmd: unbound
  • Emacs: <Ctrl+Y>

Add the most-recently killed text to the input.

YankPop

  • Cmd: unbound
  • Emacs: <Alt+Y>

If the previous operation was Yank or YankPop, replace the previously-yanked text with the next killed text from the kill ring.

ClearKillRing

  • Cmd: unbound
  • Emacs: unbound

The contents of the kill ring are cleared.

Paste

  • Cmd: <Ctrl+V>
  • Emacs: unbound

This is similar to Yank, but uses the system clipboard instead of the kill ring.

[!IMPORTANT]

When using the Paste function, the entire contents of the clipboard buffer is pasted into the input buffer of PSReadLine. The input buffer is then passed to the PowerShell parser. Input pasted using the console application's right-click paste method is copied to the input buffer one character at a time. The input buffer is passed to the parser when a newline character is copied. Therefore, the input is parsed one line at a time. The difference between paste methods results in different execution behavior.

YankLastArg

  • Cmd: <Alt+.>
  • Emacs: <Alt+.>, <Alt+_>

Insert the last argument from the previous command in history. Repeated operations replace the last inserted argument with the last argument from the previous command (so Alt+. Alt+. will insert the last argument of the second to last history line).

With an argument, the first time YankLastArg behaves like YankNthArg. A negative argument on subsequent YankLastArg calls changes the direction while going through history. For example, if you press Alt+. one too many times, you can type Alt+- Alt+. to reverse the direction.

Arguments are based on PowerShell tokens.

YankNthArg

  • Cmd: unbound
  • Emacs: <Alt+Ctrl+Y>

Insert the first argument (not the command name) of the previous command in history.

With an argument, insert the nth argument where 0 is typically the command. Negative arguments start from the end.

Arguments are based on PowerShell tokens.

Miscellaneous

Abort

  • Cmd: unbound
  • Emacs: <Ctrl+G>

Abort the current action; for example, stop interactive history search. Does not cancel input like CancelLine.

CharacterSearch

  • Cmd: <F3>
  • Emacs: <Ctrl+]>

Read a key and search forwards for that character. With an argument, search forwards for the nth occurrence of that argument. With a negative argument, searches backwards.

CharacterSearchBackward

  • Cmd: <Shift+F3>
  • Emacs: <Alt+Ctrl+]>

Like CharacterSearch, but searches backwards. With a negative argument, searches forwards.

ClearScreen

  • Cmd: <Ctrl+L>
  • Emacs: <Ctrl+L>

Clears the screen and displays the current prompt and input at the top of the screen.

DigitArgument

  • Cmd: unbound
  • Emacs: <Alt+[0..9]>,<any char>,<Alt+->

Used to pass numeric arguments to functions like CharacterSearch or YankNthArg. Alt+- toggles the argument to be negative/non-negative. To enter 80 '*' characters, you could type Alt+8 Alt+0 *.

CaptureScreen

  • Cmd: unbound
  • Emacs: unbound

Copies selected lines to the clipboard in both text and RTF formats. Use up/down arrow keys to the first line to select, then Shift+UpArrow/Shift+DownArrow to select multiple lines. After selecting, press Enter to copy the text. Escape/Ctrl+C/Ctrl+G cancel the operation, so nothing is copied to the clipboard.

InvokePrompt

  • Cmd: unbound
  • Emacs: unbound

Erases the current prompt and calls the prompt function to redisplay the prompt. Useful for custom key handlers that change state, such as changing the current directory.

WhatIsKey

  • Cmd: <Alt+?>
  • Emacs: <Alt+?>

Read a key or chord and display the key binding.

ShowKeyBindings

  • Cmd: <Ctrl+Alt+?>
  • Emacs: <Ctrl+Alt+?>

Show all of the currently-bound keys.

ScrollDisplayUp

  • Cmd: <PageUp>
  • Emacs: <PageUp>

Scroll the display up one screen.

ScrollDisplayUpLine

  • Cmd: <Ctrl+PageUp>
  • Emacs: <Ctrl+PageUp>

Scroll the display up one line.

ScrollDisplayDown

  • Cmd: <PageDown>
  • Emacs: <PageDown>

Scroll the display down one screen.

ScrollDisplayDownLine

  • Cmd: <Ctrl+PageDown>
  • Emacs: <Ctrl+PageDown>

Scroll the display down one line.

ScrollDisplayTop

  • Cmd: unbound
  • Emacs: <Ctrl+Home>

Scroll the display to the top.

ScrollDisplayToCursor

  • Cmd: unbound
  • Emacs: <Ctrl+End>

Scroll the display to the cursor.

Custom Key Bindings

PSReadLine supports custom key bindings using the cmdlet Set-PSReadLineKeyHandler. Most custom key bindings call one of the above functions, for example

Set-PSReadLineKeyHandler -Key UpArrow -Function HistorySearchBackward

You can bind a ScriptBlock to a key. The ScriptBlock can do pretty much anything you want. Some useful examples include

  • edit the command line
  • opening a new window (e.g. help)
  • change directories without changing the command line

The ScriptBlock receives two arguments:

  • $key - A [ConsoleKeyInfo] object that is the key that triggered the custom binding. If you bind the same ScriptBlock to multiple keys and need to perform different actions depending on the key, you can check $key. Many custom bindings ignore this argument.

  • $arg - An arbitrary argument. Most often, this would be an integer argument that the user passes from the key bindings DigitArgument. If your binding doesn't accept arguments, it's reasonable to ignore this argument.

Let's take a look at an example that adds a command line to history without executing it. This is useful when you realize you forgot to do something, but don't want to re-enter the command line you've already entered.

$parameters = @{
    Key = 'Alt+w'
    BriefDescription = 'SaveInHistory'
    LongDescription = 'Save current line in history but do not execute'
    ScriptBlock = {
      param($key, $arg)   # The arguments are ignored in this example

      # GetBufferState gives us the command line (with the cursor position)
      $line = $null
      $cursor = $null
      [Microsoft.PowerShell.PSConsoleReadLine]::GetBufferState([ref]$line,
        [ref]$cursor)

      # AddToHistory saves the line in history, but does not execute it.
      [Microsoft.PowerShell.PSConsoleReadLine]::AddToHistory($line)

      # RevertLine is like pressing Escape.
      [Microsoft.PowerShell.PSConsoleReadLine]::RevertLine()
  }
}
Set-PSReadLineKeyHandler @parameters

You can see many more examples in the file SamplePSReadLineProfile.ps1 which is installed in the PSReadLine module folder.

Most key bindings use some helper functions for editing the command line. Those APIs are documented in the next section.

Custom Key Binding Support APIs

The following functions are public in Microsoft.PowerShell.PSConsoleReadLine, but cannot be directly bound to a key. Most are useful in custom key bindings.

void AddToHistory(string command)

Add a command line to history without executing it.

void ClearKillRing()

Clear the kill ring. This is mostly used for testing.

void Delete(int start, int length)

Delete length characters from start. This operation supports undo/redo.

void Ding()

Perform the Ding action based on the users preference.

void GetBufferState([ref] string input, [ref] int cursor)
void GetBufferState([ref] Ast ast, [ref] Token[] tokens,
  [ref] ParseError[] parseErrors, [ref] int cursor)

These two functions retrieve useful information about the current state of the input buffer. The first is more commonly used for simple cases. The second is used if your binding is doing something more advanced with the Ast.

IEnumerable[Microsoft.PowerShell.KeyHandler]
  GetKeyHandlers(bool includeBound, bool includeUnbound)

This function is used by Get-PSReadLineKeyHandler and probably isn't useful in a custom key binding.

Microsoft.PowerShell.PSConsoleReadLineOptions GetOptions()

This function is used by Get-PSReadLineOption and probably isn't too useful in a custom key binding.

void GetSelectionState([ref] int start, [ref] int length)

If there is no selection on the command line, -1 will be returned in both start and length. If there is a selection on the command line, the start and length of the selection are returned.

void Insert(char c)
void Insert(string s)

Insert a character or string at the cursor. This operation supports undo/redo.

string ReadLine(runspace remoteRunspace,
  System.Management.Automation.EngineIntrinsics engineIntrinsics)

This is the main entry point to PSReadLine. It does not support recursion, so is not useful in a custom key binding.

void RemoveKeyHandler(string[] key)

This function is used by Remove-PSReadLineKeyHandler and probably isn't too useful in a custom key binding.

void Replace(int start, int length, string replacement)

Replace some of the input. This operation supports undo/redo. This is preferred over Delete followed by Insert because it is treated as a single action for undo.

void SetCursorPosition(int cursor)

Move the cursor to the given offset. Cursor movement is not tracked for undo.

void SetOptions(Microsoft.PowerShell.SetPSReadLineOption options)

This function is a helper method used by the cmdlet Set-PSReadLineOption, but might be useful to a custom key binding that wants to temporarily change a setting.

bool TryGetArgAsInt(System.Object arg, [ref] int numericArg,
  int defaultNumericArg)

This helper method is used for custom bindings that honor DigitArgument. A typical call looks like

[int]$numericArg = 0
[Microsoft.PowerShell.PSConsoleReadLine]::TryGetArgAsInt($arg,
  [ref]$numericArg, 1)

NOTE

POWERSHELL COMPATIBILITY

PSReadLine requires PowerShell 3.0, or newer, and the console host. It does not work in PowerShell ISE. It does work in the console of Visual Studio Code.

COMMAND HISTORY

PSReadLine maintains a history file containing all the commands and data you have entered from the command line. This may contain sensitive data including passwords. For example, if you use the ConvertTo-SecureString cmdlet the password is logged in the history file as plain text. The history files is a file named $($host.Name)_history.txt. On Windows systems the history file is stored at $env:APPDATA\Microsoft\Windows\PowerShell\PSReadLine.

FEEDBACK & CONTRIBUTING TO PSReadLine

PSReadLine on GitHub

Feel free to submit a pull request or submit feedback on the GitHub page.

SEE ALSO

PSReadLine is heavily influenced by the GNU readline library.