Robocopy not functioning in Powershell script

Question

I'm having some trouble using RoboCopy.exe through a Powershell script. The function is as follows...

function copyFiles{
    Start-Process "RoboCopy.exe" -ArgumentList "'C:\Test' 'C:\test2' /copyall"
    Write-Host 'Test'
}

"Test" is output to console but the copy does not run. I was initially attempting to copy with variables as the directories, but I've boiled it down to this since that was not working. In the directory 'test1' there is a single .txt file and 'test2' exists but is empty. I have tried it without that directory existing as well.

It is called in another file via:

. .\rCopy.ps1
copyFiles

Now, I tried outputting the log to a file with the code below, but it gives me a permissions error. "Out-File : Access to the path 'C:\Users\Me\Desktop' is denied". I also tried outputting direct to C:\ but that gives the same error. Powershell IS running as administrator.

$testCopy = Start-Process "RoboCopy.exe" -ArgumentList "'C:\Test' 'C:\test2' /copyall"
$testCopy | Out-File -LiteralPath "C:\Users\Me\

And to close, I have also tried running "Start-Process 'RoboCopy.exe' -ArgumentList 'C:\test' 'C:\test2' /copyall" in the main script, without calling the function from another.

Any help would be greatly appreciated.

Have you tested the robocopy syntax outside of powershell? Does the destination directory already exists? Out-File requires a filename, not a path. Make sure you have rights to copy files to destination, or in this case c: — Jawad, Feb 16 '20 at 18:18
As an aside: Your use of `Start-Process` may be intentional to run `RocoCopy.exe` _asynchronously_, in a _new window_, but the more typical case is to execute console applications _synchronously_, in the _same window_, in which case you need to call them _directly_ (`c:\path\to\some.exe ...` or `& $exePath ...`) - see [this answer](https://stackoverflow.com/a/51334633/45375). An alternative to asynchronous execution in a new window is to use a [background job](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_Jobs). — mklement0, Feb 16 '20 at 19:27

score 1 · Answer 1 · answered Feb 16 '20 at 18:18

I was able to get it working by using the following syntax:

Start-Process "RoboCopy.exe" -argumentlist "`"$localDir`" `"$networkDir`"  "

I cannot copy from the directory I've been trying to from the get-go, but I'm assuming that's a permissions issue.

mklement0 · Answer 2 · 2023-08-07T13:10:57.207

Your own solution is effective: quoted arguments passed to external programs such as Robocopy.exe inside a (single) -ArgumentList argument require embedded double quotes ("), not single quotes (').

Generally, external programs do not recognize ' as string delimiters on the command line, and that even applies to calling PowerShell itself via its CLI's -File parameter.

Even if you were to pass the arguments one by one to -ArgumentList:

# Note the individual arguments.
# !! Works in this case, but with paths that have *embedded spaces*
# !! you  would still need embedded "..." quoting.
Start-Process Robocopy.exe -ArgumentList 'C:\Test', 'C:\test2', '/copyall'

you'd still have to use embedded "..." quoting in individual arguments that (may) contain embedded spaces (e.g., '"C:\Test 1"' or, with a variable reference, "`"$dir`"", due to a long-standing bug that won't be fixed for the sake of backward compatibility - see GitHub issue #5576.

See this answer for background information.

Robocopy not functioning in Powershell script

2 Answers2