Write-Debug

Write-Debug [-Message*] <String> [<CommonParameters>]

The Write-Debug cmdlet writes debug messages to the console from a script or command.

By default, debug messages are not displayed in the console, but you can display them by using the Debug parameter or the $DebugPreference variable.

Parameters

-Message <String>

This value is required
Default value is None
Accepts pipeline input ByValue

Specifies the debug message to send to the console.

<CommonParameters>

This cmdlet supports the common parameters: Verbose, Debug,ErrorAction, ErrorVariable, WarningAction, WarningVariable,OutBuffer, PipelineVariable, and OutVariable.

Inputs

System.String

You can pipe a string that contains a debug message to Write-Debug .

Outputs

None

Write-Debug writes only to the debug stream. It does not return any output.

Examples

Understand $DebugPreference:
```
PS C:\>  Write-Debug "Cannot open file."
```
This command writes a debug message. Because the value of $DebugPreference is SilentlyContinue, the message is not displayed in the console.
Use the Debug parameter to override $DebugPreference:
```
PS C:\>  $DebugPreference
SilentlyContinue PS C:\>  Write-Debug "Cannot open file."
PS C:\>
PS C:\>  Write-Debug "Cannot open file." -Debug
DEBUG: Cannot open file.
```
This example shows how to use the Debug common parameter to override the value of the $DebugPreference variable for a particular command.

The first command displays the value of the $DebugPreference variable, which is SilentlyContinue, the default.

The second command writes a debug message but, because of the value of $DebugPreference, the message does not appear.

The third command writes a debug message. It uses the Debug common parameter to override the value of $DebugPreference and to display the debug messages resulting from this command.

As a result, even though the value of $DebugPreference is SilentlyContinue, the debug message appears.

For more information about the Debug common parameter, see about_CommonParameters.
Change the value of $DebugPreference:
```
PS C:\> $DebugPreference
SilentlyContinue PS C:\>  Write-Debug "Cannot open file." PS C:\>
PS C:\>  $DebugPreference = "Continue"
PS C:\>  Write-Debug "Cannot open file."
DEBUG: Cannot open file.
```
This command shows the effect of changing the value of the $DebugPreference variable on the display of debug messages.

The first command displays the value of the $DebugPreference variable, which is SilentlyContinue, the default.

The second command writes a debug message but, because of the value of $DebugPreference, the message does not appear.

The third command assigns a value of Continue to the $DebugPreference variable.

The fourth command writes a debug message, which appears on the console.

For more information about $DebugPreference, see about_Preference_Variables.

Additional Notes

This work is licensed under a Creative Commons Attribution 4.0 International. It is attributed to Microsoft Corporation and can be found here.

PowerShell Commands