This is part 9 of my series of the most common PowerShell
errors that are made in my PowerShell classes.
I will be posting one a day to help you understand why an error occurred
and what the error’s meaning is.
Today’s error: Get-CimInstance
: A positional parameter cannot be found that accepts argument '='.
Here is our starting code:
Get-CimInstance -ClassName Win32_LogicalDisk
-Filter DeviceID
= 'C:'
And here is the full error:
Get-CimInstance : A positional parameter cannot be found that
accepts argument '='.
At line:1 char:1
+ Get-CimInstance -ClassName Win32_LogicalDisk -Filter DeviceID = 3
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:)
[Get-CimInstance], ParameterBindingException
+ FullyQualifiedErrorId :
PositionalParameterNotFound,Microsoft.Management.Infrastructure.CimCmdlets.GetCimInstanceComman
d
Resolution:
Use the parameter correctly.
In this situation, I found several of my students making assumptions
about how to use the –Filter
parameter. When you are about to use a
parameter for the first time, read both the help file information for that parameter
and also look at the examples to see how to use it.
PS C:\> Get-Help Get-CimInstance -Parameter Filter
-Filter
Specifies a where
clause to use as a filter. Specify the clause in either the WQL or the CQL
query language.
Note: Do not
include the where keyword in the value of the parameter.
Required? false
Position? named
Default value
Accept pipeline
input? True (ByPropertyName)
Accept wildcard
characters? false
Example 4: Get instances of a class filtered by using a class
name and a filter expression
PS
C:\>Get-CimInstance -ClassName Win32_Process -Filter "Name like
'p%'"
This command
retrieves all the CIM instances that start with the letter p of a class named
Win32_Process using the Filter
parameter.
Here is the correct code.
We only needed to add “” to the filter.
Get-CimInstance -ClassName Win32_LogicalDisk
-Filter "DeviceID
= 'C:'"
DeviceID DriveType ProviderName VolumeName Size FreeSpace
-------- --------- ------------ ---------- ---- ---------
C: 3 OS 116280782848 2190163968
Comments