WMIC (Windows Management Instrumentation Command-line) is a powerful command-line tool that allows you to retrieve information about your Windows system. One of the useful features of WMIC is the ReturnValue property, which provides information about the success or failure of a command. In this article, we will explore how to check the value of ReturnValue of a WMIC command.
What is ReturnValue?
ReturnValue is a property that is available for most WMIC commands. It indicates the outcome of the command execution. The ReturnValue property is an integer value, and its meaning varies depending on the command you are running.
When a command is executed successfully, the ReturnValue is usually set to 0. However, if there is an error or an issue with the command execution, the ReturnValue will be a non-zero value, indicating the specific error or issue that occurred.
Checking the ReturnValue
There are a few different ways to check the ReturnValue of a WMIC command. Let's explore some of the common methods:
Method 1: Using the Command Prompt
The simplest way to check the ReturnValue is by running the WMIC command in the Command Prompt and examining the output. Here's an example:
C:\>wmic cpu get name
In this example, we are using the "cpu" alias to retrieve the name of the CPU. If the command is successful, you will see the name of your CPU in the output. However, if there is an error, you will see an error message along with the ReturnValue. For example:
ERROR:
Description = Invalid query
In this case, the ReturnValue is non-zero, indicating that there was an error with the query.
Method 2: Using a Batch File
If you are running multiple WMIC commands and want to check the ReturnValue for each command, you can create a batch file. A batch file is a script that contains a series of commands, and it allows you to automate tasks.
Here's an example of a batch file that checks the ReturnValue of two WMIC commands:
@echo off
wmic cpu get name
echo ReturnValue: %errorlevel%
wmic os get caption
echo ReturnValue: %errorlevel%
In this example, we are using the "%errorlevel%" variable to retrieve the ReturnValue. After each WMIC command, we echo the ReturnValue to the console. The "%errorlevel%" variable holds the exit code of the previously executed command.
When you run this batch file, you will see the output of the WMIC commands along with the corresponding ReturnValues.
Method 3: Using a Scripting Language
If you are comfortable with scripting languages like PowerShell or VBScript, you can use them to execute WMIC commands and retrieve the ReturnValue programmatically.
Here's an example using PowerShell:
$wmicOutput = wmic cpu get name
$returnValue = $LASTEXITCODE
Write-Host "ReturnValue: $returnValue"
In this example, we store the output of the WMIC command in the "$wmicOutput" variable, and the ReturnValue in the "$returnValue" variable. We then use the Write-Host cmdlet to display the ReturnValue.
By using a scripting language, you can perform additional operations based on the ReturnValue. For example, you can write conditional statements to handle different error scenarios.
Common ReturnValues
While the specific ReturnValues can vary depending on the command, there are some common ReturnValues that you may encounter:
| ReturnValue | Meaning |
|---|---|
| 0 | Success |
| 2 | Access denied |
| 3 | Insufficient privilege |
| 9 | Invalid namespace |
| 13 | Invalid data |
| 14 | Out of memory |
These are just a few examples, and the complete list of ReturnValues can be found in the documentation for each WMIC command.
Conclusion
The ReturnValue property of a WMIC command provides valuable information about the success or failure of the command execution. By checking the ReturnValue, you can troubleshoot issues and handle errors more effectively. Whether you use the Command Prompt, a batch file, or a scripting language, understanding how to check the ReturnValue will help you in your tech support journey.
References
| Source | Link |
|---|---|
| Microsoft Docs | https://docs.microsoft.com/en-us/windows/win32/wmisdk/wmi-return-codes |
| TechNet Magazine | https://technet.microsoft.com/en-us/library/ee692772.aspx |
| PowerShell Documentation | https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_return_values?view=powershell-7 |