I wrote a PowerShell function called Copy-WithProgress
that will achieve what you are after. Since you specifically stated that you were using robocopy, I built a PowerShell function that encapsulates the robocopy functionality (at least, parts of it).
Allow me to show you how it works. I've also recorded and posted a YouTube video demonstrating how the function is designed to work, and invoking a test run.
The function is divided into regions:
- Common robocopy parameters
- Staging (where the robocopy job size is calculated)
- Copy (where the robocopy job is kicked off)
- Progress bar (where the robocopy progress is monitored)
- Function output (where some useful statistics are outputted, for use in the rest of your script)
There are several parameters on the function.
- Source: The source directory
- Destination: The destination directory
- Gap: The "inter-packet gap" in milliseconds supported by robocopy, which artificially slows down the copy, for testing)
- ReportGap: The interval (in milliseconds) to check on robocopy progress
At the bottom of the script (after the function definition), is a complete example of how to call it. It should work on your computer, since everything is variable-ized. There are five steps:
- Generate a random source directory
- Generate a destination directory
- Call the
Copy-WithProgress
function
- Create some additional source files (to emulate changes over time)
- Call the
Copy-WithProgress
function again, and validate only changes are replicated
Here is a screenshot of what the function's output looks like. You can leave off the -Verbose
parameter, if you do not want all of the debugging information. A PSCustomObject
is returned, by the function, which tells you:
- How many bytes were copied
- How many files were copied

Here is a screenshot of the PowerShell Progress Bar in the PowerShell ISE, and the PowerShell Console Host.


Here is the code:
function Copy-WithProgress {
[CmdletBinding()]
param (
[Parameter(Mandatory = $true)]
[string] $Source
, [Parameter(Mandatory = $true)]
[string] $Destination
, [int] $Gap = 200
, [int] $ReportGap = 2000
)
# Define regular expression that will gather number of bytes copied
$RegexBytes = '(?<=\s+)\d+(?=\s+)';
#region Robocopy params
# MIR = Mirror mode
# NP = Don't show progress percentage in log
# NC = Don't log file classes (existing, new file, etc.)
# BYTES = Show file sizes in bytes
# NJH = Do not display robocopy job header (JH)
# NJS = Do not display robocopy job summary (JS)
# TEE = Display log in stdout AND in target log file
$CommonRobocopyParams = '/MIR /NP /NDL /NC /BYTES /NJH /NJS';
#endregion Robocopy params
#region Robocopy Staging
Write-Verbose -Message 'Analyzing robocopy job ...';
$StagingLogPath = '{0}\temp\{1} robocopy staging.log' -f $env:windir, (Get-Date -Format 'yyyy-MM-dd HH-mm-ss');
$StagingArgumentList = '"{0}" "{1}" /LOG:"{2}" /L {3}' -f $Source, $Destination, $StagingLogPath, $CommonRobocopyParams;
Write-Verbose -Message ('Staging arguments: {0}' -f $StagingArgumentList);
Start-Process -Wait -FilePath robocopy.exe -ArgumentList $StagingArgumentList -NoNewWindow;
# Get the total number of files that will be copied
$StagingContent = Get-Content -Path $StagingLogPath;
$TotalFileCount = $StagingContent.Count - 1;
# Get the total number of bytes to be copied
[RegEx]::Matches(($StagingContent -join "`n"), $RegexBytes) | % { $BytesTotal = 0; } { $BytesTotal += $_.Value; };
Write-Verbose -Message ('Total bytes to be copied: {0}' -f $BytesTotal);
#endregion Robocopy Staging
#region Start Robocopy
# Begin the robocopy process
$RobocopyLogPath = '{0}\temp\{1} robocopy.log' -f $env:windir, (Get-Date -Format 'yyyy-MM-dd HH-mm-ss');
$ArgumentList = '"{0}" "{1}" /LOG:"{2}" /ipg:{3} {4}' -f $Source, $Destination, $RobocopyLogPath, $Gap, $CommonRobocopyParams;
Write-Verbose -Message ('Beginning the robocopy process with arguments: {0}' -f $ArgumentList);
$Robocopy = Start-Process -FilePath robocopy.exe -ArgumentList $ArgumentList -Verbose -PassThru -NoNewWindow;
Start-Sleep -Milliseconds 100;
#endregion Start Robocopy
#region Progress bar loop
while (!$Robocopy.HasExited) {
Start-Sleep -Milliseconds $ReportGap;
$BytesCopied = 0;
$LogContent = Get-Content -Path $RobocopyLogPath;
$BytesCopied = [Regex]::Matches($LogContent, $RegexBytes) | ForEach-Object -Process { $BytesCopied += $_.Value; } -End { $BytesCopied; };
$CopiedFileCount = $LogContent.Count - 1;
Write-Verbose -Message ('Bytes copied: {0}' -f $BytesCopied);
Write-Verbose -Message ('Files copied: {0}' -f $LogContent.Count);
$Percentage = 0;
if ($BytesCopied -gt 0) {
$Percentage = (($BytesCopied/$BytesTotal)*100)
}
Write-Progress -Activity Robocopy -Status ("Copied {0} of {1} files; Copied {2} of {3} bytes" -f $CopiedFileCount, $TotalFileCount, $BytesCopied, $BytesTotal) -PercentComplete $Percentage
}
#endregion Progress loop
#region Function output
[PSCustomObject]@{
BytesCopied = $BytesCopied;
FilesCopied = $CopiedFileCount;
};
#endregion Function output
}
# 1. TESTING: Generate a random, unique source directory, with some test files in it
$TestSource = '{0}\{1}' -f $env:temp, [Guid]::NewGuid().ToString();
$null = mkdir -Path $TestSource;
# 1a. TESTING: Create some test source files
1..20 | % -Process { Set-Content -Path $TestSource\$_.txt -Value ('A'*(Get-Random -Minimum 10 -Maximum 2100)); };
# 2. TESTING: Create a random, unique target directory
$TestTarget = '{0}\{1}' -f $env:temp, [Guid]::NewGuid().ToString();
$null = mkdir -Path $TestTarget;
# 3. Call the Copy-WithProgress function
Copy-WithProgress -Source $TestSource -Destination $TestTarget -Verbose;
# 4. Add some new files to the source directory
21..40 | % -Process { Set-Content -Path $TestSource\$_.txt -Value ('A'*(Get-Random -Minimum 950 -Maximum 1400)); };
# 5. Call the Copy-WithProgress function (again)
Copy-WithProgress -Source $TestSource -Destination $TestTarget -Verbose;