#requires -version 2.0

# -----------------------------------------------------------------------------
# Script: Out-CompressedFile.ps1
# Author: Jeffery Hicks 
#    http://jdhitsolutions.com/blog
# Date: 12/6/2010
# Keywords: WMI, Out-File
# Comments: Send output to a compressed text file. This uses NTFS compression
# on a per file basis.
#
#
# "Those who forget to script are doomed to repeat their work."
#
#  ****************************************************************
#  * DO NOT USE IN A PRODUCTION ENVIRONMENT UNTIL YOU HAVE TESTED *
#  * THOROUGHLY IN A LAB ENVIRONMENT. USE AT YOUR OWN RISK.  IF   *
#  * YOU DO NOT UNDERSTAND WHAT THIS SCRIPT DOES OR HOW IT WORKS, *
#  * DO NOT USE IT OUTSIDE OF A SECURE, TEST SETTING.             *
#  ****************************************************************
# -----------------------------------------------------------------------------

Function Out-CompressedFile {

<#
   .Synopsis
    Send output to a compressed text file
    .Description
    This function is a wrapper for Out-File that redirects output to a compressed text file. File
    compression is done using the Compress() method of the WMI CIM_DATAFILE class. This will only work
    if the underlying file system is NTFS. If the file can't be compressed, the function will continue
    without it.
    
    You can append to an existing file. If it is not already compressed, it will be.
     .Parameter FilePath
    The file name. If you dont' specify a full path, the current working directory will be used.
    .Parameter InputObject
    The PowerShell objects you want to redirect.
    .Parameter Append
    Append output an existing file. The file must already exist or an exception will be thrown. If
    the file is not already compressed, it will be.
   .Example
    PS C:\Work\> dir $env:temp -recurse | out-compressedfile mytemp.txt
    Redirect the directoty listing of %TEMP% to compressed file "c:\work\mytemp.txt"
    .Example
    PS C:\> invoke-command {get-eventlog -list} -comp (get-content computers.txt) | out-compressedfile "c:\work\elogs.txt"
    Run a command on a group of remote computers and save the results to a compressed file.
   .Notes
    NAME: Out-CompressedFile
    VERSION: 1.0
    AUTHOR: Jeffery Hicks
    LASTEDIT: 12/06/2010 
    
    Learn more with a copy of Windows PowerShell 2.0: TFM (SAPIEN Press 2010)
    
   .Link
    Http://jdhitsolutions.com/blog
    .Link
    Out-File
    Out-Printer
    Out-Null
    Out-Host
    Tee-Object
    
   .Inputs
    Any object or objects
   .Outputs
    None
#>

[cmdletBinding(SupportsShouldProcess=$True)]

Param(
[Parameter(Position=0,Mandatory=$True,HelpMessage="Enter a file path and name",
ValueFromPipeline=$False)]
[ValidateNotNullorEmpty()]
[string]$FilePath,
[Parameter(Position=1,Mandatory=$False,ValueFromPipeline=$True)]
[psobject]$InputObject,
[switch]$Append
)

Begin {
    Write-Verbose -Message "$(Get-Date) Starting $($myinvocation.mycommand)"
    #get file if -append was specified
    if ($Append -AND (Test-Path $FilePath))
    {
        Write-Verbose -Message "$(Get-Date) Appending to $Filepath"
        #get full path
        if (-Not $FilePath.Contains("\"))
        {
            $FilePath=(Get-Item $filePath).fullname    
        }
    }
    elseif (-Not $Append)
    {
        #otherwise, create an empty file
        Write-Verbose -Message "$(Get-Date) Creating $FilePath"
        #if just a file name, then use the current working directory"
        if (-not $FilePath.Contains("\"))
        {
            Write-Verbose -Message "$(Get-Date) Using current working directory $PWD"
            $FilePath=Join-Path -Path (Get-item $pwd).FullName -ChildPath $FilePath
        }
        if ($pscmdlet.ShouldProcess($filepath)) 
        {
            Try
            {
                #Create the file
                $f=[System.IO.File]::Create($filepath)
                $f.Close()
                #get the full file name
                $FilePath=$f.Name
            } #close Try
            Catch
            {
                Write-Warning "Failed to create $Filepath"
                Write-Error $_
                Exit
            } #close Catch
        } #close if should process
    } #close elseif not $append
    else 
    {
        Write-Error "Failed to find $filepath. You can only append to an existing file."
        Exit
    }
    
     Write-Verbose -Message "$(Get-Date) Full path is $FilePath"
     #replace \ with \\ for WMI
     $wmipath=$filePath.Replace("\","\\")
     Write-Verbose -Message "$(Get-Date) Getting $wmipath"
     #check and see if file is already compressed
     $CIMFile=Get-WmiObject -Class CIM_DATAFILE -filter "Name='$wmipath'"
     if (-Not $CIMFile.Compressed)
     {
        #if not, compress it
        if ($pscmdlet.ShouldProcess("$Filepath"))
        {
            Write-Verbose -Message "$(Get-Date) Compressing $Filepath"
            $rc=$CIMFile.Compress()
            if ($rc.ReturnValue -ne 0)
            {
                Write-Warning "Failed to compress $Filepath. Continuing without it."
            }
         }
     } #close if not compressed
    
    #initialize a variable to hold all the input
    Write-Verbose -Message "$(Get-Date) Initializing data variable"
    $data=@()
 } #close Begin

Process {
    Foreach ($item in $InputObject) {
        $data+=$item    
    }#close Foreach 

 } #close process

End {
    Write-Verbose -Message "$(Get-Date) Sending output to $FilePath"
    #data will always be appended because the file always exists, even it is empty
    $data | Out-File -FilePath $Filepath -append
    Write-Verbose -Message "$(Get-Date) Ending $($myinvocation.mycommand)"
 } #close End

} #end Function
 
#OPTIONAL: Create an alias
#Set-Alias -Name ocf -Value Out-CompressedFile