Question

I’m writing a simple backup script in Powershell, my first powershell script actually, so I could be missing something obvious.

In command line I run this:

PS C:\tmp> $source="C:\tmp\source"
PS C:\tmp> $dest="C:\tmp\dest"
PS C:\tmp> cp "$source\*.txt" "$dest\"

and all works fine, behaves as expected: copeies all .txt files from source to dest.

when I’m in script.ps1 file, have

copyBackupFiles ("C:\tmp\source", "C:\tmp\dest")
function copyBackupFiles($Source, $Dest)
{
  Copy-Item "$Source\name.*" -Destination "$Dest\"
}

I get an error
Copy-Item : Cannot find path ‘C:\tmp\source C:\tmp\dest’ because it does not exist.

Any pointers on this problem? already spent a good couple of hours online with no luck…

Answer 1

Change the line from

copyBackupFiles ("C:\tmp\source", "C:\tmp\dest")

to

copyBackupFiles "C:\tmp\source" "C:\tmp\dest"

It’s becase you pass to parameter $source array with 2 items, but no value to $dest.

Unfortunatelly this is one of potential traps for people that know languages like C#, Java etc. Arguments are not delimitted by commas, but by space, much like in e.g. F#.

You can see wha happens with Trace-Command:

function test($a, $b) { write-host $a / $b }
Trace-Command -name parameterbinding { test (1, 2) } -PSHost
Trace-Command -name parameterbinding { test 1 2 } -PSHost