File extension while searching - powershell

Question

I am trying to get a list of all my files with a specific extension.
(...)$_.Extension -eq ".$ext"
I read extension from console to script.
My question is how to find any file with an extension of .*?
Edit:
Here's the rest of the code:
$setOfFolders = (Get-ChildItem -Path D:\ -Directory).name
Write-host "Set last write date " -ForegroundColor Yellow -NoNewline
$ostZmiana= read-host $exten = read-host "Set extensions "
ForEach ($f in $setOfFolders)
{
$saveTofile = "C:\Users\pziolkowski\Desktop\Outs\$f.txt"
Get-ChildItem -Path D:\Urzad\Wspolny\$f -Recurse | ? {$_.LastAccessTime -lt $ostZmiana -and $_.Extension -eq ".$exten"} | % {Get-acl $_.FullName} |sort Owner | ft -AutoSize -Wrap Owner, #{Label="ShortPath"; Expression= $_.Path.Substring(38)}} > $saveToFile
}

Answer 1

You can also use the -filter on Get-ChildItem:
Get-ChildItem -Filter "*.txt"
And you can specifiy recursion too:
Get-ChildItem -Recurse -Filter "*.txt"

Answer 2

The $_.Extension will see the file as, (in the case of a text file) .txt
If $ext is currently a valid extension, then .$ext would look like ..txt echoed out.
The easiest way to get a list of files with a specific extension in PowerShell is one of two, really.
C like syntax:
$myList
Get-ChildItem |`
Foreach-Object {
if ($_.Extension -eq ".txt") { $myList += $_}
}
PowerShell style:
Get-ChildItem | Where-Object {$_.Extension -eq ".txt"} | Do stuff
To get all files, as most files have an extension, just use Get-ChildItem or GCI or ls. (GCI and LS are aliases for Get-ChildItem).
To get all files with an extension, but not a specific extension:
Get-ChildItem | Where-Object {$_.Extension}
This evaluates as a bool, so true or false.
These are off the cuff, but should get you going in the right direction.