# ==============================================================================================
# 
# Microsoft PowerShell Source File -- Created with SAPIEN Technologies PrimalScript 2009
# 
# NAME: Select-PropertyValue.ps1
# 
# AUTHOR: Jeffery Hicks , SAPIEN Technologies
# DATE  : 6/10/2009
# 
# COMMENT: This function can be used in a pipelined expression
# to return all properties of a given object that have a defined value.
#
# Using an expression like: 
#
# get-process PowerShell | select *
# 
# Is a handy way to see all properties and their values. But sometimes
# you may only want to see properties that have actual values. For
# those situations, use this function.
#
# get-process PowerShell | Select-PropertyValue
#
# This if you dot source this script it will also create an
# alias for the function of spv
#
# get-process PowerShell | spv
#
# The -debug parameter will turn on debug messages. Use 
# -NoWMiSystem to filter out WMI System properties like
# __GENUS when you pipe a WMI object to the function.

# DISCLAIMER AND WARNING:
# 	THIS CODE AND INFORMATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
# 	KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# 	IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
#   TEST THOROUGHLY IN A NON-PRODUCTION ENVIRONMENT. IF YOU DON'T KNOW WHAT THIS
#   SCRIPT WILL DO...DO NOT RUN IT! 
# ==============================================================================================

Filter Select-PropertyValue {
    Param([switch]$NoWMISystem,[switch]$debug)

    if ($debug) {
        $debugPreference="Continue"
     }

    Write-Debug "In process"
    if (-Not $properties) {
        Write-Debug "Creating property list"
        #get properties for the pipelined object sorted by property name
        $properties=$_ | Get-Member -membertype Properties | sort Name
        
        #filter out WMI System properties if -NoWMISystem
        if ($NoWMISystem) {
            Write-Debug "Filtering out WMI System properties"
            $properties=$properties | where {$_.name -notlike "__*"}
        }
        
        Write-Debug "Found $($properties.count) properties"
    }
    
     #create an empty custom object
     Write-Debug "Creating empty object"
     $obj=New-Object PSObject
    
    #enumerate the list of properties
    foreach ($property in $properties) { 
        Write-Debug "Checking $($property.name)"
         #if object has a value for the current property
         if ($_.($property.name)) {       
            Write-Debug "found value $($_.($property.name))"
            
            #assign properties
            $obj | Add-Member -MemberType Noteproperty -name $property.Name -value ($_.($property.name))
                 
         } #end If
    } #end ForEach
    
    #write the custom object to the pipeline
    write $obj

} #end  function

Set-Alias -Name spv -value Select-PropertyValue

#examples
# Get-WmiObject win32_bios | spv 
# Get-WmiObject win32_logicaldisk -filter "drivetype=3" | spv -noWMISystem
# Get-Process Powershell | spv -debug
# dir c:\test\*.txt | spv | out-file data.txt