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Setting the drive letter

Posted by: | August 5, 2011 | 2 Comments |

I’ve been working on some WMI  functions for disks recently. First off setting the disk drive letter.

function set-driveletter {            
[CmdletBinding()]            
param (            
 [string]$computer=".",            
             
 [parameter(Mandatory=$true)]            
 [string]            
 [ValidatePattern("^[A-Z]{1}:{1}`$")]            
 $olddrive,            
             
 [parameter(Mandatory=$true)]            
 [string]            
 [ValidatePattern("^[A-Z]{1}:{1}`$")]            
 $newdrive            
              
)            
            
Get-WmiObject -Class Win32_Volume -ComputerName $computer -Filter "DriveLetter='$olddrive'" |             
Set-WmiInstance -Arguments @{DriveLetter=$newdrive}            
}

The difficult bit was getting the regular expression correct. It tests that we have a single letter and a colon.  The old and new drives are mandatory parameters

Simple call to Get-WmiObject and pipe to Set-WmiInstance.

Use it like this:

set-driveletter -olddrive z: -newdrive i:  

 

Jobs a good un.

under: PowerShell and WMI
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2 Comments

  1. By: Chris Warwick on August 6, 2011 at 5:49 am      

    Hi Richard,

    In the regex you don’t need to put a count of 1 (that’s implicit if you don’t specify a repetition (or use *, +, ?))

    Also, use single quotes to avoid problems with the $:

    ‘^[A-Z]:$’

    …will do it.

    Cheers,
    Chris

  2. By: RichardSiddaway on August 7, 2011 at 3:49 am      

    Thanks Chris

    The single quotes I remembered after I’d posted.

    I prefer to use the counter because it helps me remember what the regex is supposed to do. I still don’t like regex & only use it when I have to