Positioning the PowerShell Console Cursor with Write-Host
The PowerShell console supports VT escape sequences that can be used to position and format console text. Note that this works in the console only, not the PowerShell ISE. Note also that you either need Windows 10 or an emulator like ConEmu.
VT escape sequences can set the console cursor to any location inside the console window. To set the caret to the top left corner, for example, use this:
$esc = [char]27
$setCursorTop = "$esc[0;0H"
Write-Host "${setCursorTop}This always appears in line 0 and column 0!"
When you run this, the text is always located in line 0 and column 0. You can use this technique to create your own custom progress indicator – just remember: all of this works in console windows, only, not in the PowerShell ISE.
function Show-CustomProgress
{
try
{
$esc = [char]27
# let the caret move to column (horizontal) pos 12
$column = 12
$resetHorizontalPos = "$esc[${column}G"
$gotoFirstColumn = "$esc[0G"
$hideCursor = "$esc[?25l"
$showCursor = "$esc[?25h"
$resetAll = "$esc[0m"
# write the template text
Write-Host "${hideCursor}Processing %." -NoNewline
1..100 | ForEach-Object {
# insert the current percentage
Write-Host "$resetHorizontalPos$_" -NoNewline
Start-Sleep -Milliseconds 100
}
}
finally
{
# reset display
Write-Host "${gotoFirstColumn}Done. $resetAll$showCursor"
}
}
When you run this code, then enter the command Show-CustomProgress, you’ll see an incrementing custom progress indicator. The console hides the blinking prompt. When the indicator is done, or when you press CTRL+C, the progress indicator hides, and instead the word “Done.” appears. The caret starts blinking again.
Write-ConsoleExtended : Extending Write-Host
This small function is useful in that it extends the Write-Host function an provides the ability to write a certain position, and with certain colors. I used it extensively in my Custom-ProgressBar code
function Write-ConsoleExtended{
<#
.SYNOPSIS
Write a string in the console
.DESCRIPTION
Write a string in the console at specific position and color
.PARAMETER Message
Message to be printed
.PARAMETER PosX
Cursor X position where message is to be printed
.PARAMETER PosY
Cursor Y position where message is to be printed
.PARAMETER ForegroundColor
Foreground color for the message
.PARAMETER BackgroundColor
Background color for the message
.PARAMETER Clear
Clear whatever is typed on this line currently
.PARAMETER NoNewline
After printing the message, return the cursor back to its initial position
.EXAMPLE
Write-ConsoleExtended "MY TITLE" -x ([System.Console]::get_BufferWidth()/2) -f Red
Write a string in the center of screen in red
.NOTES
Author: Guillaume Plante
Last Updated: October 2022
#>
[CmdletBinding(SupportsShouldProcess)]
param(
[Parameter(Mandatory = $True, Position = 0, HelpMessage="Message to be printed")]
[Alias('m')]
[string]$Message,
[Parameter(Mandatory = $False, HelpMessage="Cursor X position where message is to be printed")]
[Alias('x')]
[int] $PosX = -1,
[Parameter(Mandatory = $False, HelpMessage="Cursor Y position where message is to be printed")]
[Alias('y')]
[int] $PosY = -1,
[Parameter(Mandatory = $False, HelpMessage="Foreground color for the message")]
[Alias('f')]
[System.ConsoleColor] $ForegroundColor = [System.Console]::ForegroundColor,
[Parameter(Mandatory = $False, HelpMessage="Background color for the message")]
[Alias('b')]
[System.ConsoleColor] $BackgroundColor = [System.Console]::BackgroundColor,
[Parameter(Mandatory = $False, HelpMessage="Clear whatever is typed on this line currently")]
[Alias('c')]
[switch] $Clear,
[Parameter(Mandatory = $False, HelpMessage="After printing the message, return the cursor back to its initial position.")]
[Alias('n')]
[switch] $NoNewline
)
$fg_color = [System.Console]::ForegroundColor
$bg_color = [System.Console]::BackgroundColor
$cursor_top = [System.Console]::get_CursorTop()
$cursor_left = [System.Console]::get_CursorLeft()
$new_cursor_x = $cursor_left
if ($PosX -ge 0) { $new_cursor_x = $PosX }
$new_cursor_y = $cursor_top
if ($PosY -ge 0) { $new_cursor_y = $PosY }
if ( $Clear ) {
[int]$len = ([System.Console]::WindowWidth - 1)
# use the string constructor for init a string with character 32 (space), len times
[string]$empty = [string]::new([char]32,$len)
[System.Console]::SetCursorPosition(0, $new_cursor_y)
[System.Console]::Write($empty)
}
[System.Console]::ForegroundColor = $ForegroundColor
[System.Console]::BackgroundColor = $BackgroundColor
[System.Console]::SetCursorPosition($new_cursor_x, $new_cursor_y)
# Write the message, if NoNewline, go ack to beginning
[System.Console]::Write($Message)
if ( $NoNewline ) {
[System.Console]::SetCursorPosition($cursor_left, $cursor_top)
}
# back to previous colors
[System.Console]::ForegroundColor = $fg_color
[System.Console]::BackgroundColor = $bg_color
}
Write-ConsoleExtended : Example Usage
function Write-FlashingText{
[CmdletBinding(SupportsShouldProcess)]
param(
[Parameter(Mandatory = $True, Position = 0, HelpMessage="Message to be printed")]
[Alias('m')]
[string]$Message
)
cls
$e = "$([char]27)"
#hide the cursor
Write-Host "$e[?25l" -NoNewline
[int]$len = ([System.Console]::WindowWidth - 1)
[string]$empty = [string]::new("=",$len)
$cl = $True
For($i = 0 ; $i -lt 100 ; $i++){
$cl = !$cl
$color1 = "DarkRed"
$color2 = "DarkYellow"
if($cl){
$color1 = "DarkYellow"
$color2 = "DarkRed"
}
cls
$TitleLen = $Message.Length
$posx = ([System.Console]::get_BufferWidth()/2) - ($TitleLen/2)
Write-ConsoleExtended $empty -f $color1
Write-ConsoleExtended "$Message" -x $posx -y ([System.Console]::get_CursorTop()+1) -f $color2
Write-ConsoleExtended "`n$empty`n" -f $color1
Start-Sleep -Millisecond 500
}
#show the cursor
Write-Host "$e[?25h"
}
Draw Boxes ! :)
Here’s another example, this code will draw lines, and 4 lines = a boxe :)
function DrawLine([int]$x, [int]$y, [int]$length,[int]$vertical){
Write-ConsoleExtended "*" $x $y -nonewline
# Is this vertically drawn? Set direction variables and appropriate character to draw
If ([boolean]$vertical){
$linechar='!'; $vert=1;$horz=0
}else{
$linechar='-'; $vert=0;$horz=1
}
foreach ($count in 1..($length-1)) {
Write-ConsoleExtended $linechar (($horz*$count)+$x) (($vert*$count)+$y) -f DarkRed -nonewline
}
# Bump up the counter and draw the end
$count++
Write-ConsoleExtended '*' (($horz*$count)+$x) (($vert*$count)+$y) -f DarkYellow -nonewline
}
Clear-Host
DrawLine -x 5 -y 5 -length 5 -vertical 0
DrawLine -x 5 -y 10 -length 5 -vertical 0
DrawLine -x 5 -y 5 -length 5 -vertical 5
DrawLine -x 10 -y 5 -length 5 -vertical 5
Checkout this custom progress bar that makes usage of the information in this post
-
PowerShell.CustomProgressBarhttps://github.com/arsscriptum/PowerShell.NativeProgressBar
Important Note Do You have Issues accessing the core repository? Don’t be shy and send me an EMAIL at guillaumeplante.qc@gmail.com and I will fix access for you
