Get-Process | Tee-Object -FilePath "C:\Test1\testfile2.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
Example 2: Output processes to a variable and `Select-Object`
This example gets a list of the processes running on the computer, saves them to the $proc
variable, and pipes them to Select-Object.
Get-Process notepad | Tee-Object -Variable proc | Select-Object processname,handles
ProcessName Handles
----------- -------
notepad 43
notepad 37
notepad 38
notepad 38
The Select-Object cmdlet selects the ProcessName and Handles properties. Note that the
$proc variable includes the default information returned by Get-Process.
Example 3: Output system files to two log files
This example saves a list of system files in a two log files, a cumulative file and a current file.
Get-ChildItem -Path D: -File -System -Recurse |
Tee-Object -FilePath "c:\test\AllSystemFiles.txt" -Append |
Out-File c:\test\NewSystemFiles.txt
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.
Example 4: Print output to console and use in the pipeline
This example gets the files in a folder, prints them to the console, then filters the files for
those that have a defined front matter metadata block. Finally, it lists the names of the articles
that have front matter.
$consoleDevice = if ($IsWindows) {
'\\.\CON'
} else {
'/dev/tty'
$frontMatterPattern = '(?s)^---(?<FrontMatter>.+)---'
$articles = Get-ChildItem -Path .\reference\7.4\PSReadLine\About\ |
Tee-Object -FilePath $consoleDevice |
Where-Object {
(Get-Content $_ -Raw) -match $frontMatterPattern
$articles.Name
Directory: C:\code\docs\PowerShell-Docs\reference\7.4\PSReadLine\About
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 12/13/2022 11:37 AM 384 .markdownlint.yaml
-a--- 4/25/2023 11:28 AM 40194 about_PSReadLine_Functions.md
-a--- 4/25/2023 10:58 AM 10064 about_PSReadLine.md
about_PSReadLine_Functions.md
about_PSReadLine.md
The example sets the $consoleDevice variable to the value of the current terminal's console
device. On Windows, you can write to the current console device by redirecting your output to the
\\.\CON filepath. On non-Windows systems, you use the /dev/tty filepath.
Then it sets the $frontMatterPattern variable to a regular expression that matches when a string
starts with three dashes (---) and has any content before another three dashes. When this pattern
matches an article's content, the article has a defined front matter metadata block.
Next, the example uses Get-ChildItem to retrieve every file in the About folder. Tee-Object
prints the piped results to the console using the FileName parameter. Where-Object filters
the files by getting their content as a single string with the Raw parameter of Get-Content
and comparing that string to $frontMatterPattern.
Finally, the example prints the names of the files in the folder that have a defined front matter
metadata block.
Parameters
-Append
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.
Type:SwitchParameter
Position:Named
Default value:False
Accept pipeline input:False
Accept wildcard characters:False
-Encoding
Specifies the type of encoding for the target file. The default value is utf8NoBOM.
The acceptable values for this parameter are as follows:
ascii: Uses the encoding for the ASCII (7-bit) character set.
bigendianunicode: Encodes in UTF-16 format using the big-endian byte order.
oem: Uses the default encoding for MS-DOS and console programs.
unicode: Encodes in UTF-16 format using the little-endian byte order.
utf7: Encodes in UTF-7 format.
utf8: Encodes in UTF-8 format.
utf8BOM: Encodes in UTF-8 format with Byte Order Mark (BOM)
utf8NoBOM: Encodes in UTF-8 format without Byte Order Mark (BOM)
utf32: Encodes in UTF-32 format.
Beginning with PowerShell 6.2, the Encoding parameter also allows numeric IDs of registered code
pages (like -Encoding 1251) or string names of registered code pages (like
-Encoding "windows-1251"). For more information, see the .NET documentation for
Encoding.CodePage.
This parameter was introduced in PowerShell 7.2.
UTF-7* is no longer recommended to use. As of PowerShell 7.1, a warning is written if you
specify utf7 for the Encoding parameter.
Type:Encoding
Accepted values:ASCII, BigEndianUnicode, OEM, Unicode, UTF7, UTF8, UTF8BOM, UTF8NoBOM, UTF32
Position:1
Default value:UTF8NoBOM
Accept pipeline input:False
Accept wildcard characters:False
-FilePath
Specifies a file that this cmdlet saves the object to Wildcard characters are permitted, but must
resolve to a single file.
Starting in PowerShell 7, when you specify the FilePath as \\.\CON on Windows or /dev/tty
on non-Windows systems, the InputObject is printed in the console. Those file paths correspond
to the current terminal's console device on the system, enabling you to print the InputObject
and send it to the output stream with one command.
Type:String
Aliases:Path
Position:0
Default value:None
Accept pipeline input:False
Accept wildcard characters:True
-InputObject
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 is treated as a single object even if the value is a
collection.
Type:PSObject
Position:Named
Default value:None
Accept pipeline input:True
Accept wildcard characters:False
-LiteralPath
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 PowerShell not to interpret any characters as escape sequences.
Type:String
Aliases:PSPath, LP
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Variable
Specifies a variable that the cmdlet saves the object to. Enter a variable name without the
preceding dollar sign ($).
Type:String
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
PSObject
You can pipe objects to this cmdlet.
Outputs
PSObject
This cmdlet returns the object that it redirects.
Notes
PowerShell includes the following aliases for Tee-Object:
Windows:
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.
Beginning in PowerShell 6, Tee-Object uses BOM-less UTF-8 encoding when it writes to files. If you
need a different encoding, use the Out-File cmdlet with the Encoding parameter.
Compare-Object
ForEach-Object
Group-Object
Measure-Object
New-Object
Select-Object
Sort-Object
Where-Object
about_Redirection
