Prof. Powershell

Values, Separated at Commas

The ConvertTo-CSV cmdlet, new with PowerShell 2.0, gives you a bit more flexibility in how you plug into CSV-formatted info.

• By Jeffery Hicks
• 12/01/2009

I think it's fair to say that the comma-separated value format is an important part of any Windows administrator toolkit, especially if scripting is involved. PowerShell has always supported this format with the Import-CSV and Export-CSV cmdlets. Getting data into a CSV file relies on the latter cmdlet, but it forces you to save the information to a text file.

What if you want to use the data in the CSV format, perhaps as a PowerShell variable? Or maybe you need to use something other than a comma as the separator? PowerShell 2.0 introduces the ConvertTo-CSV cmdlet.

You use ConvertTo-CSV in the same way you might use Export-CSV. Instead of writing output to a file, it is written to the pipeline:

PS C:\> gwmi win32_logicaldisk -filter "drivetype=3" | Select DeviceID,Size,Freespace,VolumeName,SystemName | convertto-csv
#TYPE Selected.System.Management.ManagementObject
"DeviceID","Size","Freespace","VolumeName","SystemName"
"C:","119926681600","51621163008","","GODOT7"
"F:","320070287360","99858821120","VM","GODOT7"

Just like Export-CSV, the cmdlet includes a TYPE line; you can use -NoTypeInformation to eliminate it:

PS C:\> $d= gwmi win32_logicaldisk -filter "drivetype=3" | Select DeviceID,Size,Freespace,VolumeName,SystemName | convertto-csv -NoTypeInformation

Personally, I've not found much practical use for something like this. Although PowerShell now includes a corresponding ConvertFrom-CSV cmdlet that is the equivalent of Import-CSV:

PS C:\> ConvertFrom-CSV $d

DeviceID   : C:
Size       : 119926681600
Freespace  : 51621105664
VolumeName :
SystemName : GODOT7

DeviceID   : F:
Size       : 320070287360
Freespace  : 99858821120
VolumeName : VM
SystemName : GODOT7

These are custom objects, not WMI objects, but you can work with them as you would any other object in PowerShell.

Finally, if you need a file that uses a semicolon as a delimiter -- perhaps you plan on using the file somewhere else -- this cmdlet offers the flexibility you'll need:

PS C:\> gwmi win32_logicaldisk -filter "drivetype=3" | Select DeviceID,Size,Freespace,VolumeName,SystemName | convertto-csv -NoTypeInformation -Delimiter ";" | out-file drivedata.txt

I still think the comma is king in PowerShell 2.0 and now you have a few more tools to work with data the way you want without having to parse a lot of text or jump through a lot of hoops.