PowerShell - Overwriting line written with Write-Host - powershell

Question

I'm trying to overwrite a line in PowerShell written with Write-Host (I have a process that's running in a loop and I want to show percentage updated on the screen). What I've tried to do is this:
Write-Host -NoNewline "`rWriting $outputFileName ($i/$fileCount)... $perc%"
but instead of overwriting the line it stays on the same line and appends to it.
what am I missing here?
Thanks

Answer 1

You cannot overwrite a line in a Powershell window. What you can do is blank the window with cls(Clear-Host):
# loop code
cls
Write-Host "`rWriting $outputFileName ($i/$fileCount)... $perc%"
# end loop
But what you should really be using is Write-Progress, a cmdlet built specifically for this purpose:
# loop code
Write-Progress -Activity "Writing $outputFileName" -PercentComplete $perc
# end loop
More on Write-Progress here: http://technet.microsoft.com/en-us/library/hh849902.aspx

Answer 2

As a tweak to Raf's answer above, You don't have to wipe the screen every time to update your last line.
Calling Write-Host with -NoNewLine and carriage return `r is enough.
for ($a=0; $a -le 100; $a++) {
Write-Host -NoNewLine "`r$a% complete"
Start-Sleep -Milliseconds 10
}
Write-Host #ends the line after loop

Answer 3

It not perfect but here is a script which has a spinning character in place. The part that lets you do this is:
$origpos = $host.UI.RawUI.CursorPosition
$origpos.Y += 1
Get the current position and save it so that we can keep referring to it. As you progress you change the $host.UI.RawUI.CursorPosition. Since it was previously saved you can reset it back $host.UI.RawUI.CursorPosition = $origpos. You should be able to experiment with that.
$scroll = "/-\|/-\|"
$idx = 0
$job = Invoke-Command -ComputerName $env:ComputerName -ScriptBlock { Start-Sleep -Seconds 10 } -AsJob
$origpos = $host.UI.RawUI.CursorPosition
$origpos.Y += 1
while (($job.State -eq "Running") -and ($job.State -ne "NotStarted"))
{
$host.UI.RawUI.CursorPosition = $origpos
Write-Host $scroll[$idx] -NoNewline
$idx++
if ($idx -ge $scroll.Length)
{
$idx = 0
}
Start-Sleep -Milliseconds 100
}
# It's over - clear the activity indicator.
$host.UI.RawUI.CursorPosition = $origpos
Write-Host 'Complete'
Remove-Variable('job')
$job = Start-Job -ScriptBlock { Start-Sleep -Seconds 10 }
while (($job.State -eq "Running") -and ($job.State -ne "NotStarted"))
{
Write-Host '.' -NoNewline
Start-Sleep -Seconds 1
}
Write-Host ""
So as log as you remember where you want to go back to then you can use this logic. This will not work properly in ISE. You can also use `b as a back space character as well.

Answer 4

I know, thats quite old, but i was in the same Situation und modified the Solution from Boluwade Kujero, just because writing blank lines before writing the new output may result in a "flickering" output.
So in the following function, I just do overwrite the existing line, write blanks until reaching the old cursorposition, and go back to the last character of the new line.
In addition i added an optical progressbar. Progress is calculated by the function through given Parameters:
function Write-Status
{
param([int]$Current,
[int]$Total,
[string]$Statustext,
[string]$CurStatusText,
[int]$ProgressbarLength = 35)
# Save current Cursorposition for later
[int]$XOrg = $host.UI.RawUI.CursorPosition.X
# Create Progressbar
[string]$progressbar = ""
for ($i = 0 ; $i -lt $([System.Math]::Round($(([System.Math]::Round(($($Current) / $Total) * 100, 2) * $ProgressbarLength) / 100), 0)); $i++) {
$progressbar = $progressbar + $([char]9608)
}
for ($i = 0 ; $i -lt ($ProgressbarLength - $([System.Math]::Round($(([System.Math]::Round(($($Current) / $Total) * 100, 2) * $ProgressbarLength) / 100), 0))); $i++) {
$progressbar = $progressbar + $([char]9617)
}
# Overwrite Current Line with the current Status
Write-Host -NoNewline "`r$Statustext $progressbar [$($Current.ToString("#,###").PadLeft($Total.ToString("#,###").Length)) / $($Total.ToString("#,###"))] ($($( ($Current / $Total) * 100).ToString("##0.00").PadLeft(6)) %) $CurStatusText"
# There might be old Text behing the current Currsor, so let's write some blanks to the Position of $XOrg
[int]$XNow = $host.UI.RawUI.CursorPosition.X
for ([int]$i = $XNow; $i -lt $XOrg; $i++) {
Write-Host -NoNewline " "
}
# Just for optical reasons: Go back to the last Position of current Line
for ([int]$i = $XNow; $i -lt $XOrg; $i++) {
Write-Host -NoNewline "`b"
}
}
Use the function like this:
For ([int]$i=0; $i -le 8192; $i++) {
Write-Status -Current $i -Total 8192 -Statustext "Running a long Task" -CurStatusText "Working on Position $i"
}
The result will be a running progressbar that will look like this (in a single line):
Running a long Task ██████████████████░░░░░░░░░░░░░░░░░ [4.242 /
8.192] ( 51,78 %) Working on Position 4242
Hope this will help someone else

Answer 5

You can use the .NET console class to do exactly what you want where you want it.
Works in console windows only and not the ISE.
cls
[Console]::SetCursorPosition(40,5)
[Console]::Write('Value of $i = ')
[Console]::SetCursorPosition(40,7)
[Console]::Write('Value of $j = ')
For ($i = 1; $i -lt 11; $i++)
{
[Console]::SetCursorPosition(57,5)
[Console]::Write($i)
for ($j = 1; $j -lt 11; $j++)
{
[Console]::SetCursorPosition(57,7)
[Console]::Write("$j ")
Start-Sleep -Milliseconds 200
}
Start-Sleep -Milliseconds 200
}
[Console]::SetCursorPosition(40,5)
[Console]::Write(" `n")
[Console]::SetCursorPosition(40,7)
[Console]::Write(" `n")
[Console]::SetCursorPosition(0,0)

Answer 6

If the goal is strictly to overwrite powershell console prompt line (the current line with the cursor) then all the answers here work only to an extent, and in some ways doing more than is desired.
Raf's and Craig's answers that use the Clear-Host cmdlet (cls) in their first line, like Dullson noted, are doing too much. Blanking the entire screen assumes the things cleared are no longer important for viewing which may not be true. Sometimes these are necessary to make sense of the current line.
Raf's Write-Progress solution is a powerful cmdlet but seems like an overkill for just overwriting the current line.
Raf's Write-Host proposal, Matt's submission and Dullson's tweak are all good where only one character position at a definite screen position needs updating or where the succeeding line text is longer in length than the current. If not, the succeeding line text would only overwrite the current line to the extent of its length leaving those parts of the succeeded line whose length position is longer than the new to remain in view together with the new line.
For example, if the previous value was 10 and the new value is 9 what would be shown is 90. The 9 just overwrites the portion of the preceding value that is equal to its length - 1. So the solutions work well for increments but not so well for decrements where length of value reduces compared to previous.
The following block shows how to guarantee total (visual) overwrite of the current line text with a new one.
$LongString = "This string is long"
$ShortString = "This is short"
#Simulate typing a string on the console line
$L = 1
While ($L -le $LongString.Length)
{
$Sub = $LongString.Substring(0,$L)
Write-Host "`r$Sub" -NoNewline
$L++
# This sleep is just to simulate manual typing delay
Start-Sleep -Milliseconds 20
}
# Now blank out the entire line with the space character " "
# The quantity of spaces should be equal to the length of the current text
# Which in this case is contained in $Sub.Length
$Blank = " "
For($L = 1; $L -le $Sub.Length; $L++)
{
$Blank = $Blank + " "
}
Write-Host "`r$Blank" -NoNewline
# Overwrite the blank console line with the new string
$L = 1
While ($L -le $ShortString.Length)
{
$Sub = $ShortString.Substring(0,$L)
Write-Host "`r$Sub" -NoNewline
$L++
# This sleep is just to simulate delay in manual typing
Start-Sleep -Milliseconds 20
}
# The following is not required if you want the Powershell prompt
# to resume to the next line and not overwrite current console line.
# It is only required if you want the Powershell prompt to return
# to the current console line.
# You therefore blank out the entire line with spaces again.
# Otherwise prompt text might be written into just the left part of the last
# console line text instead of over its entirety.
For($L = 1; $L -le $Sub.Length; $L++)
{
$Blank = $Blank + " "
}
Write-Host "`r$Blank" -NoNewline
Write-Host "`r" -NoNewline

Answer 7

This one I got from a blog post by Thomas Rayner. He uses ANSI Escape Sequences to save the cursor position [s and update the cursor position [u
$E=[char]27
Then save the current cursor position using the save escape sequence:
"${E}[s"
Usage: Use the update sequence ${E}[u to tell PS where to start the string:
1..10 | %{"${E}[uThere are $_ s remaining"; Start-Sleep -Seconds 1}
Does not work in the ISE however.
I know links get stale but it is here today.

Answer 8

Try
for ($i=1;$i -le 100;$i++){Write-Host -NoNewline "`r" $i;sleep 1}

Answer 9

https://241931348f64b1d1.wordpress.com/2017/08/23/how-to-write-on-the-same-line-with-write-output/
This method worked for me to write output value in a loop until its status changed to "Succeeded". Ensure you set the cursor up by required number of lines and it overwrites the same line
while($val -ne 1)
{
if($taskstates.Tasks.state[0] -eq "Succeeded" -and $taskstates.Tasks.state[1] -eq "Succeeded" -and $taskstates.Tasks.state[2] -eq "Succeeded" -and $taskstates.Tasks.state[3] -eq "Succeeded")
{
$val = 1
}
#Clear-Host
$taskstates.Tasks.StartTime[0].ToString() +" "+ $taskstates.Tasks.name[0] +" is "+ $taskstates.Tasks.state[0]
$taskstates.Tasks.StartTime[1].ToString() +" "+ $taskstates.Tasks.name[1] +" is "+ $taskstates.Tasks.state[1]
$taskstates.Tasks.StartTime[2].ToString() +" "+ $taskstates.Tasks.name[2] +" is "+ $taskstates.Tasks.state[2]
$taskstates.Tasks.StartTime[3].ToString() +" "+ $taskstates.Tasks.name[3] +" is "+ $taskstates.Tasks.state[3]
$taskstates = Get-ASRJob -Name $failoverjob.Name
"ASR VMs build is in Progress"
Start-Sleep 5
[console]::setcursorposition($([console]::Cursorleft ),$([console]::CursorTop - 4))
}

Answer 10

I'm late to the party. Here's a proof of concept I recently discovered and adapted for my purposes. This example overwrites the line.
$count = 1
# Used for calculating the max number length for padding trailing spaces
$totalCount = 100
#Get current cursor position
$curCursorPos = New-Object System.Management.Automation.Host.Coordinates
$curCursorPos.X = $host.ui.rawui.CursorPosition.X
$curCursorPos.Y = $host.ui.rawui.CursorPosition.Y
# Counter code
While ($count -le 100) {
# Keep cursor in the same position on the same line
$host.ui.rawui.CursorPosition = $curCursorPos
# Display with padded trailing spaces to overwrite any extra digits
$pad = ($totalCount -as [string]).Length
# Display the counter
Write-Host "$(([string]$count).Padright($pad))" -NoNewline -ForegroundColor Green
# Run through the example quickly
Start-Sleep -Milliseconds 100
#increment $count
$count++
}
You can experiment with Write-Host -NoNewline property, by keeping it or removing it, to see which looks better for you.

Answer 11

I like below code...
$dots = ""
while (!$isTrue) {
if ($dots -eq "...") {
$dots = ""
}
else {
$dots += "."
}
Write-Host -NoNewLine "`rLoading$dots"
Start-Sleep 1
}

Answer 12

You can use $Host.UI.RawUI.WindowSize.Width to find the display width and then use .PadRight to fill up the line with spaces. This avoids having to clear the screen with each loop, the issue of characters persisted from the last loop, having to manipulate cursor position, or having to write a custom function or lots of cumbersome code, e.g.:
# only works in a console window
If ($Host.Name -eq "ConsoleHost")
{
Write-Host 'Starting...'
# find the max line length of the console host
$maxLineLength = $Host.UI.RawUI.WindowSize.Width
# loop a few times
For ($i = 1; $i -le 10; $i++)
{
# for the sake of demonstration, generate a random-length string of letters
$randStringLength = Get-Random -Minimum 1 -Maximum $maxLineLength
$randCharIndex = Get-Random -Minimum 65 -Maximum (65+26) # A = ASCII 65
$randChar = ([char]$randCharIndex)
$myString = [string]$randChar*$randStringLength
# overwrite at the current console line
Write-Host ("`r"+$myString.PadRight($maxLineLength," ")) -NoNewline
# pause briefly before going again
Start-Sleep -Milliseconds 200
}
Write-Host 'Done.'
}
Another option in PowerShell 7.2+ is to use the minimal Write-Progress view $PSStyle.Progress.View = Minimal:
# only works in a console window
If ($Host.Name -eq "ConsoleHost")
{
# loop a few times
For ($i = 1; $i -le 10; $i++)
{
# for the sake of demonstration, generate a random-length string of letters
$randStringLength = Get-Random -Minimum 1 -Maximum 500
$randCharIndex = Get-Random -Minimum 65 -Maximum (65+26) # A = ASCII 65
$randChar = ([char]$randCharIndex)
$myString = [string]$randChar*$randStringLength
# overwrite at the current console line
Write-Progress -Activity $i -Status $myString
# pause briefly before going again
Start-Sleep -Milliseconds 200
}
}

Answer 13

Alot of good suggestions here...
I use the WindowTitle bar for monitoring the status of my scripts, indicate where I am within my code, & the current progress.
For($t = 0; $t -le 100; $t++) {
$Host.UI.RawUI.WindowTitle = "Progress - $t% complete"
Start-Sleep -Milliseconds 10
}
I'll even insert updated "position" info within my code, to indicate where I'm at within my code:
$Host.UI.RawUI.WindowTitle = "Querying index..."
$Host.UI.RawUI.WindowTitle = "Updating search field..."
$Host.UI.RawUI.WindowTitle = "Conducting Robocopy..."
and of course when it's completed:
$Host.UI.RawUI.WindowTitle = "Script completed."