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Write-Output

  • Reference
Module:
Microsoft.PowerShell.Utility

Writes the specified objects to the pipeline.

Syntax

Write-Output
     [-InputObject] <PSObject[]>
     [-NoEnumerate]
     [<CommonParameters>]

Description

Writes the specified objects to the pipeline. If Write-Output is the last command in the pipeline, the objects are displayed in the console.

Write-Output sends objects to the primary pipeline, also known as the success stream. To send error objects to the error stream, use Write-Error.

This cmdlet is typically used in scripts to display strings and other objects on the console. One of the built-in aliases for Write-Output is echo and similar to other shells that use echo. The default behavior is to display the output at the end of a pipeline. In PowerShell, it is generally not necessary to use the cmdlet in instances where the output is displayed by default. For example, Get-Process | Write-Output is equivalent to Get-Process. Or, echo "Home directory: $HOME" can be written, "Home directory: $HOME".

By default, Write-Output enumerates objects in a collection. However, Write-Output can also pass collections down the pipeline as a single object with the NoEnumerate parameter.

Examples

Example 1: Get objects and write them to the console

In this example, the results of the Get-Process cmdlet are stored in the $P variable. The Write-Output cmdlet displays the process objects in $P to the console.

$P = Get-Process
Write-Output $P

Example 2: Pass output to another cmdlet

This command pipes the "test output" string to the Get-Member cmdlet, which displays the members of the System.String class, demonstrating that the string was passed along the pipeline.

Write-Output "test output" | Get-Member

Example 3: Suppress enumeration in output

This command adds the NoEnumerate parameter to treat a collection or array as a single object through the pipeline.

Write-Output 1,2,3 | Measure-Object

Count    : 3
...

Write-Output 1,2,3 -NoEnumerate | Measure-Object

Count    : 1
...

Parameters

-InputObject

Specifies the objects to send down the pipeline. Enter a variable that contains the objects, or type a command or expression that gets the objects.

Type:PSObject[]
Position:0
Default value:None
Required:True
Accept pipeline input:True
Accept wildcard characters:False

-NoEnumerate

By default, the Write-Output cmdlet always enumerates its output. The NoEnumerate parameter suppresses the default behavior, and prevents Write-Output from enumerating output. The NoEnumerate parameter has no effect if the command is wrapped in parentheses, because the parentheses force enumeration. For example, (Write-Output 1,2,3) still enumerates the array.

The NoEnumerate parameter is only useful within a pipeline. Trying to see the effects of NoEnumerate in the console is problematic because PowerShell adds Out-Default to the end of every command line, which results in enumeration. But if you pipe Write-Output -NoEnumerate to another cmdlet, the downstream cmdlet receives the collection object, not the enumerated items of the collection.

Important

There is an issue with this switch in Windows PowerShell that is fixed in PowerShell 6.2 and above. When using NoEnumerate and explicitly using the InputObject parameter, the command still enumerates. To work around this, pass the InputObject argument(s) positionally.

Type:SwitchParameter
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

Inputs

PSObject

You can pipe objects to this cmdlet.

Outputs

PSObject

This cmdlet returns the objects that are submitted as input.

Notes

Windows PowerShell includes the following aliases for Write-Output:

  • echo
  • write