7zip - powershell exclude files/folders with variable - powershell

Question

I'm trying to zip a folder but exclude multiple directories using powershell.
I got the following:
if (-not (test-path "$env:ProgramFiles\7-Zip\7z.exe")) {throw "$env:ProgramFiles\7-Zip\7z.exe needed"}
set-alias sz "$env:ProgramFiles\7-Zip\7z.exe"
$Source = "D:\Zip\*"
$Target = "D:\backup.7z"
$exclude = 'Customer\Images\*'
sz a -xr!'$Customer\Images\*' $Target $Source
This works fine.. But when I want the change the -xr! to -xr!'$exclude' or -xr!$exclude it stops working for some reason. Does the variable assigned above not get parsed?

Answer 1

Try this...
if (-not (Test-Path "$env:ProgramFiles\7-Zip\7z.exe")) {throw "$env:ProgramFiles\7-Zip\7z.exe needed"}
$7ZipPath = "$env:ProgramFiles\7-Zip\7z.exe"
$Source = "D:\Zip\*"
$Target = "D:\backup.7z"
$foldersToExclude = 'folder1', 'folder2'
$7zipParams = #('a',$Target)
#($foldersToExclude) | ForEach-Object { $7zipParams += "`"-xr!$_`"" }
$7zipParams += $Source
Write-Host ($7ZipPath+' '+$7zipParams -join ' ') # debug - show the command line
&$7ZipPath $7zipParams
We create an array of params to pass into 7zip, including the excluded folders. As we're appending the excluded folders, we prepend the folder names with the -xr! flags and wrap these in double qoutes.
The #debug line outputs the resultant command line to the console
I call 7zip slightly differently to you, by creating a string with the 7zip executable, then prepending the call to that string path with an ampersand.
This method can exclude multiple folders from the final archive, including folder\subfolder structure.

Answer 2

Two things:
Use the variable inside double quotes if you want it to be expanded:sz a "-xr!$exclude" $Target $Source
Using the pattern Customer\Images\* excludes all files in the directory Images, but includes an empty directory in the resulting file. Use Customer\Images if you don't want to include the directory (or any of its files).