Prof. Powershell

Enum's the Limit

Let's start off 2012 with a tip I learned just recently: Using the PowerShell $FormatEnumerationLimit variable to customize the number of entries viewable via the Dir command.

• By Jeffery Hicks
• 01/05/2012

During the PowerShell Deep Dive conference in Frankfurt last year, PowerShell MVP Thomas Lee, offered up a handy tidbit I thought I should share. I'm sure many of you have run a command like this:

PS C:\> dir hklm:software\microsoft | sort valuecount -desc

   Hive: HKEY_LOCAL_MACHINE\software\microsoft

SKC   VC   Name              Property
---   --   ----              --------
  0   22   NetSh             {4, nshwfp, dhcpclient, wshelper...}
  1   13   FTH               {MaximumMemoryPressurePercentage, Max...
  3   10   InetStp           {SetupString, MajorVersion, IISProgra...
 33    9   Internet Explorer {MkEnabled, Version, Build, W2kVersio...
 17    9   Windows Search    {indexer:ci:MaxRestrictionNodes, Curr...
...

Notice the nested Property value for these entries. The ellipse (...) indicates there are more property values. It might be easier to see them this way:

PS C:\> dir hklm:software\microsoft | sort valuecount -desc | Select -first 4 | format-list

Name        : NetSh
ValueCount  : 22
Property    : {4, nshwfp, dhcpclient, wshelper...}
SubKeyCount : 0

Name        : FTH
ValueCount  : 13
Property    : {MaximumMemoryPressurePercentage,
               MaximumTrackedApplications,
               CheckPointPeriod,
               MaximumDelayFreeOverheadInMBs...}
SubKeyCount : 1

Name        : InetStp
ValueCount  : 10
Property    : {SetupString, MajorVersion, IISProgramGroup,
               VersionString...}
SubKeyCount : 3

Name        : Internet Explorer
ValueCount  : 9
Property    : {MkEnabled, Version, Build, W2kVersion...}
SubKeyCount : 33

Did you also notice that at most all you get is four entries? Turns out there is a built-in PowerShell variable that controls the number of enumerated entries. It has a default value of 4:

PS C:\> $FormatEnumerationLimit
4

But we can modify this variable:

PS C:\> $FormatEnumerationLimit=8

Now watch what happens. I'll use the same Format-List command which makes it easier to see the result:

PS C:\> dir hklm:software\microsoft | sort valuecount -desc | Select -first 4 | format-list

Name        : NetSh
ValueCount  : 22
Property    : {4, nshwfp, dhcpclient, wshelper,
               nshhttp, fwcfg, authfwcfg, 2...}
SubKeyCount : 0

Name        : FTH
ValueCount  : 13
Property    : {MaximumMemoryPressurePercentage,
               MaximumTrackedApplications,
               CheckPointPeriod,
               MaximumDelayFreeOverheadInMBs,
               RuleList, Enabled, TicketValue,
               CrashWindowInMinutes...}
SubKeyCount : 1

Name        : InetStp
ValueCount  : 10
Property    : {SetupString, MajorVersion, IISProgramGroup,
               VersionString, MinorVersion,
               MetabaseSetMajorVersion,
               MetabaseSetMinorVersion, ProductString...}
SubKeyCount : 3

Name        : Internet Explorer
ValueCount  : 9
Property    : {MkEnabled, Version, Build, W2kVersion,
               IntegratedBrowser, svcKBFWLink,
               svcVersion, svcUpdateVersion...}
SubKeyCount : 33

Now PowerShell returned eight nested entries! You can make this variable as large as you think it needs to be. If I set it to a high value, I'm likely to get all the entries:

PS C:\> $FormatEnumerationLimit=64
PS C:\> dir hklm:software\microsoft | sort valuecount -desc | Select –first 1 | format-list

Name        : NetSh
ValueCount  : 22
Property    : {4, nshwfp, dhcpclient, wshelper, nshhttp, fwcfg,
               authfwcfg, 2, netiohlp, whhelper, hnetmon, rpc,
               dot3cfg, napmontr, nshipsec, nettrace, WcnNetsh,
               p2pnetsh, wwancfg, wlancfg, peerdistsh, 7}
SubKeyCount : 0

Of course, as soon as I start a new PowerShell session I'm back to the default value of 4. So if you want a more permanent setting, you'll need to set the value for $FormatEnumerationLimit in your profile.