HowTo: Reading / Searching through XML Files

#--------------------==--------------------#
 #--------------  Description --------------#
 #
 # This script takes an input file (example shown below) and looks
 # for any Public Folders where the items counts for all the
 # replicas are not identical.
 
 #--------------- Input File ---------------#
 # 
 # The input file is generated from the output of my PowerShell script
 # Compare_Public_Folders_Between_Ex2000_and_Ex2007.ps1.  An excerpt of
 # this file is shown below.
 # <?xml version="1.0" encoding="ISO-8859-1"?>
 # <Public_Folders>
 #   <x />
 #   <Run_Details>
 #     <Start>
 #       <TimeStamp>
 #         <Year>2008</Year>
 #         <Month>7</Month>
 #         <Day>15</Day>
 #         <Time>13:28:23</Time>
 #       </TimeStamp>
 #     </Start>
 #     <Finish>
 #       <TimeStamp>
 #         <Year>2008</Year>
 #         <Month>7</Month>
 #         <Day>15</Day>
 #         <Time>15:23:26</Time>
 #       </TimeStamp>
 #     </Finish>
 #     <Parameters>
 #       <Connect_As_Identiy>UserID</Connect_As_Identiy>
 #       <New_Server>NewMailServer</New_Server>
 #       <Old_Server>OldMailServer</Old_Server>
 #       <Security_Permission_Mode>Add</Security_Permission_Mode>
 #     </Parameters>
 #   </Run_Details>
 #   <Public_Folder ID="3">
 #     <Name>Access Issues</Name>
 #     <Path>\Access\Access Issues</Path>
 #     <Friendly_Web_Address>HTTP://OldMailServer/public/Access/Access Issues</Friendly_Web_Address>
 #     <Proper_Web_Address>HTTP://OldMailServer/public/Access/Access%20Issues</Proper_Web_Address>
 #     <Replica>
 #       <Server_Name>cocsxchng01</Server_Name>
 #       <Web_Address_Header>http://OldMailServer</Web_Address_Header>
 #     </Replica>
 #     <Replica>
 #       <Server_Name>NewMailServer</Server_Name>
 #       <Web_Address_Header>https://NewMailServer</Web_Address_Header>
 #       <Item_Count>26</Item_Count>
 #       <Byte_Count>540999</Byte_Count>
 #     </Replica>
 #   </Public_Folder>
 
 
 #----------------- Output -----------------#
 #
 # This is an example of the output that is displayed on screen.
 #
 # Item Count mismatch for folder 
 #     \Finance\Conference Call Calendar
 #     OldMailServer :  71
 #     NewMailServer :  55
 # Item Count mismatch for folder
 #     \Marketing\Administration\Team A
 #     OldMailServer :  2655
 #     NewMailServer :  2653
 # Done.
 
 
 set-psdebug –strict;    # Require declaration of powershell variables
 # Set-PSDebug -Off;        # Do not require declaration of variables
 $strPathToFile         = "U:\Development";
 $strFileName         = "XMLDoc.old.txt";
 $xmlLog             = [xml]( Get-Content (join-path -path $strPathToFile $strFileName));
 $colPublicFolders     = $xmlLog.Public_Folders.Public_Folder;
 
 foreach ($objPublicFolder in $colPublicFolders) {
     # If there was only one replica for a folder, then 
     # ($objPublicFolder.Replica -is [array]) would return false
     if ($objPublicFolder.Replica -is [array]) {
         $Item_Count_for_First_Replica = $objPublicFolder.Replica[0].Item_Count;
         $colReplicas = $objPublicFolder.Replica;
         $mismatch = $False;
         # Compare the item count for each replica against
         # the first replica item count.
         foreach ($objReplica in $colReplicas) {
             If ($objReplica.Item_Count -ne $Item_Count_for_First_Replica) {
                 $mismatch = $True;
             }
         }
         if ($mismatch -eq $True) {
             Write-Host "Item Count mismatch for folder`n`t" $objPublicFolder.Path;
             foreach ($objReplica in $colReplicas) {
                 Write-Host "`t" $objReplica.Server_Name ": " $objReplica.Item_Count;}
         }
     }
     $colReplicas = $Null;
     $Item_Count_for_First_Replica = $Null;
     $objReplica = $Null;
 }
 $strPathToFile = $Null
 $strFileName = $Null
 $objPublicFolder = $Null;
 $colPublicFolders = $Null;
 $xmlLog = $Null;
 Write-Host "Done.";