Powershell Remove-Item IF file already exists after Copy-item - powershell

Question

I need to add a safety net in my script. I'm trying to do a copy job based on a list of users provided through a txt file. Copy the files from that users home directory to a new location. Once the files are copied, check if the file exists in the new location. If yes, then Remove-Item.
Can someone help me? I just don't know how to implement the "if file exists" logic.
$username = Get-Content '.\users.txt'
foreach ($un in $username)
{
$dest = "\\server\homedirs\$un\redirectedfolders"
$source = "\\server\homedirs\$un"
New-Item -ItemType Directory -Path $dest\documents, $dest\desktop
Get-ChildItem $source\documents -Recurse -Exclude '*.msg' | Copy-Item -Destination $dest\documents
Get-ChildItem $source\desktop -Recurse -Exclude '*.msg' | Copy-Item -Destination $dest\desktop
Get-ChildItem $source\mydocuments, $source\desktop -Recurse -Exclude '*.msg' | Remove-Item -Recurse
}

Answer 1

The shortest way to delete file if it doesn't exist is NOT to use Test-Path but:
rm my_file.zip -ea ig
This is short version of
rm my_file.zip -ErrorAction Ignore
which is much more readable and more DRY then
if (Test-Path my_file.zip) { rm my_file.zip }

Answer 2

To answer your question per se, you can do it like this:
Get-ChildItem $source\mydocuments, $source\desktop -Recurse -Exclude '*.msg' | %{
if (Test-Path ($_. -replace "^$([regex]::escape($source))","$dest")) {
Remove-Item $_ -Recurse
}
}
Test-Path returns $true if the file at the given path exists, otherwise $false.
$_ -replace "^$([regex]::escape($source))","$dest" converts the path of each source item you're enumerating with the corresponding destination path, by replacing $source at the beginning of the path with $dest.
The basic regex for the first argument to the -replace operator is ^$source (which means "match the value of $source at the beginning of the string"). However, you need to use [regex]::escape in case $source contains any regex special characters, which is in fact extremely likely with Windows paths, since they contain backslashes. For example, the value you've given here for $source contains \s, which in a regex means "any whitespace character". $([regex]::escape($source)) will interpolate the value of $source with any regex special characters properly escaped, so that you're matching the explicit value.
That said, if your purpose is to copy each item to a new location, and remove the original only if the copy to the new location is successful, it seems like you're reinventing the wheel. Why not just use Move-Item instead of Copy-Item?
Not directly related to the question, but rather than repeating the same command for each subdirectory, you can use a foreach loop:
foreach ($subdir in (echo documents desktop)) {
# Whatever command you end up using to copy or move the items,
# using "$source\$subdir" and "$dest\$subdir" as the paths
}

Answer 3

Test-Path commandlet will help you check if the file exists
http://technet.microsoft.com/en-us/library/ee177015.aspx

Answer 4

#Adi Inbar, I need to use a function like this because I need to move files to a remote session, and the Move-Item does not work when I tried -ToSession... only Copy-Item.
The Key is that if the power or internet goes down, the script will delete the file even if it wasn't copied.
$username = "name"
$password = ConvertTo-SecureString "password" -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential -ArgumentList ($username, $password)
$Session = New-PSSession -ComputerName "IPAdress" -Credential $credential
Copy-Item -Path C:\userPC_1\csv-output\*.csv -Destination C:\userPC_2\Documents\Test_Scripts -ToSession $Session -Verbose
Get-PSSession | Remove-PSSession
Get-ChildItem -Path C:\userPC_1\csv-output\*.csv | Remove-Item -Force