How to checkin SPCheckedOutFile

Question

In Powershell i get all checked out file from a library with

foreach($f in $lib.CheckedOutFiles){
    //I tried to retrieve item with 
    $item = $lib.GetItemById($f.ListItemID)//exception item not retrieve
}

How can i checkin spcheckedoutfile?

SOLUTION

I finally found a solution. For having item i have to do a TakeOverCheckOut before and after i can have item and file to checkin

foreach ($item in $lib.CheckedOutFiles) {
    write-Host $item.ListitemId
    $item.TakeOverCheckOut()//to retrieve item i have to do this before
    $doc = $lib.getItemById($item.ListitemId)
    $itemFile = $doc.File
    if($itemFile -ne $null){
        $itemFile.CheckIn("Checked In By Administrator for achive")
        write-Host " Checked In" -ForeGroundColor Green
    }

}

Answer 1

To check-in all files within a specific library, try this

$spWeb = Get-SPWeb http://yoursite/
$splist = $spWeb.Lists |? {$_.Title -eq "libname"}
foreach ($item in $splist.Items) 
{
    if( $item.File.CheckOutStatus -ne "None" )
    { 
        $item.File.CheckIn("Checkedin")
    }
}
$spWeb.Dispose()

Check also how to checkin all checked out files via powershell?