Putting the Squeeze on Files with PowerShell

My December Mr. Roboto column is now online This month’s tool is a PowerShell WinForm script that uses WMI to compress files. I used PrimalForms 2009 to build the graphical interface. The interface is essentially a wizard that lets you build a WMI query to find files and compress them.

Results can be logged to a CSV file or you can merely list the files that match the search criteria. Here’s a code excerpt.

$Compress={
    #initialize some variables
    $filters=@()
    $i=0
    $richtextbox1.Clear()
    $drive=$txtPath.Text.Substring(0,2)
    $filter="Drive='$drive' AND Compressed='False' AND Encrypted='FALSE'"
    $blnLog=$false
    
    $form1.Cursor="WaitCursor"
    
    if ($chkLogResults.checked) {
        #create a file for logging
        $timestamp=(get-date).toString('yyyMMddhhmmss')
        $logfile="Squeeze_$timestamp.log"
        $blnLog=$True
        #create the header
        "Server,Name,Extension,FileSize,LastModified,CreationDate,Drive,Path,Result" | out-file $logfile
    }
 
    #check other filter options
    if ($chkSize.Checked) {
        #add file size to filter
        [int]$FileSizeValue=$txtFileSize.Text
        $size=$FileSizeValue*1KB
        $filter+=" AND filesize >= $size"
    }
    
    
    if ($chkDate.Checked) {
         #convert datetime to a WMI datetime
        $datetime=[System.Management.ManagementDateTimeConverter]::ToDmtfDateTime($datetimepicker1.Value)
        $filter+=" AND LastModified >= '$datetime'"
    } #end if $chkDate.Checked
    
    if ($chkFileExtensions.Checked) {
        $arrExtensions=$txtExtensions.Text.split(",")
        $extensionFilter=" "
        for ($c=0;$c -lt $arrExtensions.Count;$c++) {
            $extensionFilter+="extension='$($arrExtensions[$c])'"
            if ($c -ne $arrExtensions.count-1) {
            $extensionFilter+=" OR "
            }
        }
                
        $filter+=" AND ($extensionFilter)"
    } #end if $chkFileExtensions.Checked
    
    #create a copy of the filter up to this point
    $basefilter=$filter
    
    #get base path
    if ($txtPath.Text.Length -eq 3) {
        #check if drive root
        $filepath="\\"
        $filter+=" AND path='$filepath'"
    }
    else {
           #parse out file path
           $filepath=$txtPath.Text.Substring(2)
           #replace \ with \\
           $filepath=$filepath.Replace("\","\\")
           $filter+=" AND path='$filepath\\'"
     }
    
    #add the base path to the set of filters
    $filters+=$filter
    
    if ($chkRecurse.Checked) {
 
       #process subfolders
       $p=$txtPath.Text
       dir $p  -rec | 
       where {$_.psIsContainer} | foreach {
           #replace \ with \\ and append the trailing \\
        $filepath="{0}\\" -f $_.fullname.substring(2).replace("\","\\")
        #append each filepath to a copy of the basefilter
        $tempFilter=$basefilter
        $tempfilter+=" AND path='$filepath'"
        
        #add each subfolder path to the collection of WMI query filters
        $filters+=$tempfilter
        } #end foreach
      
    } #end if $chkRecurse.checked
    
 
    foreach ($item in $filters) {
        #run a WMI query for each filter
        $cmd=("get-wmiobject -class CIM_DataFile -filter ""{0}""" -f "$item")
        
#        write-host $item -foregroundcolor CYAN
        
        $statusbar1.text="Running Query $item"
        $files=Invoke-Expression $cmd 
        
        if ($files) {
            foreach ($file in $files) {
                $i+=1
                $line="{0}`n" -f $file.name
                $richtextbox1.text+=$line
                $form1.Refresh()
                #compress the file if list only NOT checked
                if (! $chkListOnly.Checked) {
                    $rc=$file.Compress()
                    $result=$rc.returnValue
                }
                else {
                    $result="NA"
                }
                #log the results if checked
                if ($chkLogResults.checked) {
#                    "Server,Name,Extension,FileSize,LastModified,CreationDate,Drive,Path,Result"
                    $data="{0},{1},{2},{3},{4},{5},{6},{7},{8}" -f $file.CSName,$file.Name,$file.Extension,$file.FileSize,$file.ConvertToDateTime($file.LastModified),$file.ConvertToDateTime($file.CreationDate),$file.Drive,$file.path,$result
                    $data | out-file $logfile -append
                }
            } #end foreach $file in $files
        
        } #end if $files
        
        if ($i -gt 0) {
            $statusbar1.text="Found $i file(s) to compress"
        }
        else {
            $statusbar1.text="Failed to find any files to compress."
        }
            
    } #end foreach
    $form1.Cursor="Default"
    
    
    if ($blnLog) {notepad $logfile}
} #end Compress

The script has (I think) a nice example of providing popup help. You can download a zip file with the script and PrimalForms 2009 source file from the Mr. Roboto article.

Thanks to Wes Stahler for being such a willing lab rat.