Using regular expressions inside of a hashtable in PowerShell?

Question

I have the following hashtable:

$lookupTable = @{
    "^XXX"="123";
    "^YYY"="456";
    "cat"="dog"
}

I'm performing a bulk find & replace operation in files as such:

Foreach-Object {
    $file = $_
    Write-Host "$file"
    (Get-Content -Path $file) | ForEach-Object {
        $line = $_
        $lookupTable.GetEnumerator() | ForEach-Object {
            $line = $line -replace "$_.Name", "$_.Value"
        }
        $line
    } | Set-Content -Path $file
}

You'll notice I have an anchor/caret (^) on the first two pairs of the hashtable. This is because I want to perform a regex on these so they only match if they are at the beginning of the line. For the third set ("cat"="dog") I want to match anywhere (no regular expressions). Unfortunatley, it seems to be taking the ^ literally and is not finding matches nor doing a regex evaluation. I tried defining the regex like below and it works for the first two sets ("XXX"="123" & "YYY"="456"), but it won't work for the third set ("cat"="dog") as I need to find cat anywhere in the file, not just at the beginning of the line:

$line = $line -replace "^$($_.Name)", "$($_.Value)"

How can I accomplish this? Thank you very much.

Answer 1

I figured it out. The trick was to remove the quotes (") from $line = $line -replace "$_.Name", "$_.Value" so it would actually interpolate the item vs. treating it as a literal string. So the correct code should be:

$line = $line -replace $_.Name, $_.Value