Tee-Object

Saves command output in a file or variable and also sends it down the pipeline.
Tee-Object [-FilePath*] <String> [-Append] [-InputObject [<PSObject>]] [<CommonParameters>]
Tee-Object [-InputObject [<PSObject>]] -LiteralPath* <String> [<CommonParameters>]
Tee-Object [-InputObject [<PSObject>]] -Variable* <String> [<CommonParameters>]

The Tee-Object cmdlet redirects output, that is, it sends the output of a command in two directions (like the letter T). It stores the output in a file or variable and also sends it down the pipeline. If Tee-Object is the last command in the pipeline, the command output is displayed at the prompt.

Parameters
-Append [<SwitchParameter>]

Indicates that the cmdlet appends the output to the specified file. Without this parameter, the new content replaces any existing content in the file without warning.

This parameter was introduced in Windows PowerShell 3.0.

-FilePath <String>

  • This value is required
  • Default value is None

Specifies a file that this cmdlet saves the object to. Wildcard characters are permitted, but must resolve to a single file.

-InputObject [<PSObject>]

Specifies the object to be saved and displayed. Enter a variable that contains the objects or type a command or expression that gets the objects. You can also pipe an object to Tee-Object.

When you use the InputObject parameter with Tee-Object, instead of piping command results to Tee-Object, the InputObject value-even if the value is a collection that is the result of a command, such as InputObject (Get-Process)-is treated as a single object. Because InputObject cannot return individual properties from an array or collection of objects, it is recommended that if you use Tee-Object to perform operations on a collection of objects for those objects that have specific values in defined properties, you use Tee-Object in the pipeline, as shown in the examples in this topic.

-Variable <String>

  • This value is required

Specifies a variable that the cmdlet saves the object to. Enter a variable name without the preceding dollar sign ($).

-LiteralPath <String>

  • This value is required

Specifies a file that this cmdlet saves the object to. Unlike FilePath, the value of the LiteralPath parameter is used exactly as it is typed. No characters are interpreted as wildcards. If the path includes escape characters, enclose it in single quotation marks. Single quotation marks tell Windows PowerShell not to interpret any characters as escape sequences.

<CommonParameters>

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

Inputs

System.Management.Automation.PSObject

You can pipe objects to Tee-Object.

Outputs

System.Management.Automation.PSObject

Tee-Object returns the object that it redirects.

Examples
  1. Output processes to a file and to the console:
    PS C:> Get-Process | Tee-Object -FilePath "C:Test1testfile2.txt"
    
       Handles  NPM(K)    PM(K)      WS(K) VM(M)   CPU(s)    Id ProcessName
       -------  ------    -----      ----- -----   ------    -- -----------
       83       4     2300       4520    39     0.30    4032 00THotkey
       272      6     1400       3944    34     0.06    3088 alg
       81       3      804       3284    21     2.45     148 ApntEx
       81       4     2008       5808    38     0.75    3684 Apoint
       ...

    This command gets a list of the processes running on the computer and sends the result to a file. Because a second path is not specified, the processes are also displayed in the console.

  2. Output processes to a variable and Select-Object:
    PS C:> Get-Process notepad | Tee-Object -Variable proc | Select-Object processname,handles
    
       ProcessName                              Handles
       -----------                              -------
       notepad                                  43
       notepad                                  37
       notepad                                  38
       notepad                                  38

    This command gets a list of the processes running on the computer and sends the result to a variable named proc. It then pipes the resulting objects along to Select-Object, which selects the ProcessName and Handles property. Note that the $proc variable includes the default information returned by Get-Process.

  3. Output system files to two log files:
    PS C:> Get-ChildItem -Path D: -File -System -Recurse | Tee-Object -FilePath "c:testAllSystemFiles.txt" -Append | Out-File c:testNewSystemFiles.txt
    

    This command saves a list of system files in a two log files, a cumulative file and a current file.

    The command uses the Get-ChildItem cmdlet to do a recursive search for system files on the D: drive. A pipeline operator (|) sends the list to Tee-Object, which appends the list to the AllSystemFiles.txt file and passes the list down the pipeline to the Out-File cmdlet, which saves the list in the NewSystemFiles.txt file.

Additional Notes
 You can also use the Out-File cmdlet or the redirection operator, both of which save the output in a file but 
 do not send it down the pipeline.
 Tee-Object uses Unicode encoding when it writes to files. As a result, the output might not be formatted 
 properly in files with a different encoding. To specify the encoding, use the Out-File cmdlet.
Related Links

Compare-Object
ForEach-Object
Group-Object
Measure-Object
New-Object
Select-Object
Sort-Object
Where-Object