Display variables values at different scopes

I have an automated process for building the necessary regular expression using Emacs. It has a function called regexp-opt which builds an optimized regular expression to search for a list of words.The result is converted to a Powershell regex with a list of string replacements such as “\(” to “(” etc.

######################################################################
#
#                               MYVARS
#
#   Displays *ALL* Non-AUTOMATIC PS Variables in a scope range.
#   With the -del option it cleans up the variables in that range.
#   Requires Get-MaxScopeID posted by Kiron 20080917.
#
######################################################################
function MyVars([int]$minScope=0,
                [int]$maxScope=$(Get-MaxScopeID),
                [switch]$del) {
$ScopeLimit = (Get-MaxScopeID)
if ($minScope -gt $maxScope){throw "Myvars [<min>] [<max>]"}
"Maximum Scope range specification is 0..$($ScopeLimit - 1)"
if ($minScope -lt 0 -or $maxScope -lt 0){throw "Scope out of range."}
$maxScope++                     #These offsets are to account
$minScope++                     #for $this scope which goes away
if ($maxScope -gt $ScopeLImit){$maxScope = $ScopeLimit}
if ($minScope -gt $maxScope)  {$minScope = $maxScope}
$minScope..$maxScope|%{Get-Variable -scope $_|Select-Object Name,Value|
                       Add-Member noteproperty 'Scope' ($_ - 1) -passthru}|
 ?{$_.name -notmatch (
   '^(Co(?:mmandLineParameters|n(?:(?:firmPreferenc|soleFileNam)e))|DebugPref' +
   'erence|E(?:rror(?:ActionPreference|View)?|xecutionContext)|FormatEnumerat' +
   'ionLimit|H(?:OME|ost)|L(?:ASTEXITCODE|oad_Library_Paths)|M(?:aximum(?:(?:' +
   'Alias|Drive|Error|Function|History|Variable)Count)|yInvocation)|NestedPro' +
   'mptLevel|OutputEncoding|P(?:ID|ROFILE|S(?:BoundParameters|C(?:mdlet|ultur' +
   'e)|EmailServer|HOME|MaximumReceived(?:(?:DataSizePerCommand|ObjectSize)MB' +
   ')|Session(?:(?:Applic|Configur)ationName)|TypePath|(?:UICultur|VersionTab' +
   'l)e)|WD|rogressPreference)|ReportErrorShow(?:ExceptionClass|InnerExceptio' +
   'n|S(?:(?:our|tackTra)ce))|S(?:hellId|tackTrace)|VerbosePreference|W(?:SMa' +
   'nMaxRedirectionCount|(?:arning|hatIf)Preference)|args|false|input|null|pa' +
   'ttern|true|[$?_^])$'
   )}|
 %{Add-Member -in $_ noteproperty 'Type'  $(if ($_.Value){
              $_.Value.PSTypeNames[0]}else{'Null'}) -passthru}|
 Sort-Object -property scope,name|
 %{if ($del) {Remove-Variable $_.Name -scope ($_.Scope + 1)
              "Deleted $($_.name)"}else{$_}}|
 Format-Table Scope,Name,Type,Value -a
}
######################################################################
#
#                             Get-MaxScopeID
#
#   Returns the numeric -scope value currently equivalent to 'global'
#   Posted by iron 20080917 on microsoft.public.windows.powershell NG
#
######################################################################
function Get-MaxScopeID () {
 # -2 below accounts for function and foreach scopes which go away
 trap {return ([int]$id - 2)}
 foreach ($id in 0..100) {
  gv -s $id >$null
 }
}

Generic way to see if an object is castable to another type

This function provides a generic way to tell if a given object can safely be cast to another type.

It returns a boolean value (True False) so it can also be used as a filter in a pipeline.

filter Global:CanBe([string]$Type,$InputObject) {
  begin {if ($InputObject){$InputObject|CanBe $Type}}
  process { if (!$InputObject) {
    Invoke-Expression "&{trap {`$false;continue};[boolean]([$Type]`$_)}"}
  }
}

Here are some test cases you can try.

CanBe int 'rick'
CanBe int '12,345'
'abc',123,'124',@(),{throw},@('hu',1)|CanBe int
'abc',123,'124',@(),{throw},@('hu',1)|CanBe string
'abc',123,'124',@(),{throw},@('hu',1)|CanBe scriptblock
'abc',123,'124',@(),{throw},@('hu',1)|CanBe object[]
'abc',123,'124',@(),{throw},@('hu',1)|?{CanBe scriptblock $_}
'abc',123,'124',@(),{throw},@('hu',1)|?{CanBe string $_}

By Rick Bielawski | Posted in PowerShell | Comments (0)