Filtering files by partial name match

Question

I have a network share with 20.000 XML files in the format

username-computername.xml

There are duplicate entries in the form of (when a user received a n

Answer 1

You can use Group-Object to group files by a custom attribute:

$xmlfiles | Group-Object { $_.Name.Split('-')[0] }

The above statement will produce a result like this:

Count Name    Group
----- ----    -----
    1 BLRPPR  {BLRPPR-SKB52084.xml}
    1 BLRSIA  {BLRSIA-SKB50871.xml}
    2 S028DS  {S028DS-SKB51334.xml, s028ds-SKB52424.xml}
    2 S02FL6  {S02FL6-SKB51644.xml, S02FL6-SKB52197.xml}
    1 S02VUD  {S02VUD-SKB52083.xml}

where the Group property contains the original FileInfo objects.

Expand the groups in a ForEach-Object loop, sort each group by LastWriteTime, and select the most recent file from it:

... | ForEach-Object {
  $_.Group | Sort-Object LastWriteTime -Desc | Select-Object -First 1
}