Improving the speed of Get-FileMetaData

Question

I'm currently using the below script taken from scriptingguys.com (all credit to them, I just added the bottom 2 lines.) That takes a directory and pulls the file path and comments field from the meta data of the files. Currently the script take's a little over 1.5 minutes to fully run. Is there anyway to speed this up or use a different method to get this data?

I am using this script at the start of some software I have written and 1.5+ minutes is too long for the script to complete. Any thoughts/comments?

Function Get-FileMetaData
{
 Param([string[]]$folder)
 foreach($sFolder in $folder)
  {
   $a = 0
   $objShell = New-Object -ComObject Shell.Application
   $objFolder = $objShell.namespace($sFolder)

   foreach ($File in $objFolder.items())
    { 
     $FileMetaData = New-Object PSOBJECT
      for ($a ; $a  -le 266; $a++)
       { 
         if($objFolder.getDetailsOf($File, $a))
           {
             $hash += @{$($objFolder.getDetailsOf($objFolder.items, $a))  =
                   $($objFolder.getDetailsOf($File, $a)) }
            $FileMetaData | Add-Member $hash
            $hash.clear() 
           } #end if
       } #end for 
     $a=0
     $FileMetaData
    } #end foreach $file
  } #end foreach $sfolder
} #end Get-FileMetaData

$fileMetaData = Get-FileMetaData -folder "C:\Pics" | select 'Name', 'Path', 'Comments' | Sort-Object 'Name'
$fileMetaData | select 'Name', 'Path', 'Comments' | Export-CSV "C:\SCRIPTS\TestDirectory.txt" -encoding Utf8 -NoTypeInformation

Solved by wOxxOm, thanks for your help! Running the below and now working.

Function Get-FileMetaData(
    [string[]]$folders,
    [string[]]$properties
) {
    $shellApp = New-Object -ComObject Shell.Application
    $supportsOrdered = $PSVersionTable.PSVersion.Major -ge 3
    $hash = if ($supportsOrdered) { [ordered]@{} } else { @{} }
    # walk the folders and get the properties by index found above
    $folders | ForEach {
        $shellFolder = $shellApp.namespace($_)
        # get all headers and find their indexes
        $allProps = @{}
        foreach ($index in 0..266) {
            $allProps[$shellFolder.getDetailsOf($shellFolder.items, $index)] = $index
        }
        $shellFolder.items() | ForEach {
            $file = $_
            $hash.Clear()
            foreach ($prop in $properties) { 
                if (($index = $allProps[$prop]) -ne $null) {
                    if ($value = $shellFolder.getDetailsOf($file, $index)) {
                        $hash[$prop] = $value
                    }
                }
            }
            if ($supportsOrdered) {
                [PSCustomObject]$hash
            } else {
                Select $properties -inputObject (
                    New-Object PSObject -Property $hash
                )
            }
        }
    }
}
Get-FileMetaData  -folders 'C:\PICS' -properties Name, Path, Comments | Sort-Object Name |
    select Name, Path, Comments | Export-Csv 'C:\Scripts\test.txt' -encoding UTF8 -NoTypeInformation

Answer 1

1. getDetailsOf is slow, and your code needlessly invokes it 267 times for each file when you only need it for 3 properties.
2. Collect the property names just once at the start of the function, don't do it on every file
3. Add-Member is slow. Don't invoke it on every property. Collect all found properties in a hashtable and pass it once to Add-Member or, since you create an empty object, directly to New-Object. To enforce the order of properties use Select-Object in PowerShell 2. Note, PowerShell 3.0 and newer support [ordered] and [PSCustomObject] typecast (see the code below).
4. Use pipelining instead of foreach statements so that the results appear immediately
5. Files are already sorted by name, at least on NTFS file system in Windows, so no need to sort.

Function Get-FileMetaData(
    [string[]]$folders,
    [string[]]$properties
) {
    $shellApp = New-Object -ComObject Shell.Application
    # get all headers and find their indexes
    $shellFolder = $shellApp.namespace($folders[0])
    $allProps = @{}
    foreach ($index in 0..266) {
        $allProps[$shellFolder.getDetailsOf($shellFolder.items, $index)] = $index
    }
    $supportsOrdered = $PSVersionTable.PSVersion.Major -ge 3
    $hash = if ($supportsOrdered) { [ordered]@{} } else { @{} }
    # walk the folders and get the properties by index found above
    $folders | ForEach {
        $shellFolder = $shellApp.namespace($_)
        $shellFolder.items() | ForEach {
            $file = $_
            $hash.Clear()
            foreach ($prop in $properties) { 
                if (($index = $allProps[$prop]) -ne $null) {
                    $hash[$prop] = $shellFolder.getDetailsOf($file, $index)
                }
            }
            if ($supportsOrdered) {
                [PSCustomObject]$hash
            } else {
                Select $properties -inputObject (
                    New-Object PSObject -Property $hash
                )
            }
        }
    }
}

Usage example 1:

Get-FileMetaData -folders 'r:\folder1', 'r:\folder2' -properties Name, Path, Comments

Usage example 2:

Get-FileMetaData -folders 'r:\folder1', 'r:\folder2' -properties Name, Path, Comments |
    Export-Csv r:\results.csv -encoding UTF8 -NoTypeInformation

Usage example 3 gets all properties, which is slow:

Get-FileMetaData -folders 'r:\folder1', 'r:\folder2'