Windows PowerShell's  Built-in Cmdlets

Windows PowerShell's - Build-in Cmdlets

On this page I define the word cmdlet to mean a built-in PowerShell command, with a single verb-noun pair.  There is another shade of meaning to cmdlet, namely a series of commands, usually more than one line, stored in a text file with a .ps1 extension.  This page deals with the first meaning and includes a review of PowerShell's built-in cmdlets.

Here are the 13 sections of PowerShell's built-in cmdlets.

1. System Built-in Cmdlets
2. Objects Built-in Cmdlets
3. Items Built-in Cmdlets
4. Aliases Built-in PowerShell Cmdlets
5. Drives Built-in Cmdlets
6. Paths and locations
7. Contents Built-in PowerShell Cmdlets
8. Access Operating System Components
9. Output Formatters Built-in Cmdlets
10. Variables
11. Security Built-in Cmdlets
12. Miscellaneous PowerShell Built-in Cmdlets
13. Debugging

PowerShell Build-in Cmdlet Categories

1) System Built-in Cmdlets

a) get-help.  This is the best command to explore the built-in PowerShell library.  As with many cmdlets, it begins with the verb 'get'.  Example: get-help alias.  Remember that get-help supports wildcards, for example type:
get-help *object.

b) get-command.  Returns a list of available commands.  Get-command really is the entire command, I was expecting more, but this cmdlet is only two words, get and command separated by a hyphen.  You may wish to try a wild card, for example get-command c*

c) get-host.  Displays information about the PowerShell host. (Not to be confused with hostname.)  Try this command to check your version number.

d) get-culture.  Shows you information about the regional settings of the host (as defined in the Regional Settings of the Control Panel)

e) get-uiculture Returns information about the regional settings of the host as defined by the selected language on a multi-language operating system.

See more about key system cmdlets here

2) Objects Built-in Cmdlets

a) get-Member.  This is by far the most important cmdlet.  get-Member enumerates properties, methods and type information of the objects; for example:

get-WmiObject | get-Member
Special note, the pipeline symbol displays as ¦ in PowerShell, but as | in notepad.  See a whole page on get-Member

b) foreach-object.   The purpose of this cmdlet is to loop through multiple instances, such as disk drives.  Foreach applies a block of script to each object in the pipeline.  For example;

$Nic= get-WmiObject Win32_NetworkAdapterConfiguration
foreach ( $MacAdr in $Nic ) { "Mac Address = " + $MacAdr.MacAddress}

Note that the type of bracket is significant, () or {} each have a distinct role (condition) {script block}.  Also note the + which not only adds numbers, but also is the same symbol that concatenates text.

c) where-object (Often abbreviated to plain 'where') filters the input from the pipeline, allowing operation on only certain objects.  For example:

get-service | where-object {$_.status -eq "Stopped"}

d) new-object.  Creates instances of .NET or COM objects.  New-object is particularly useful for creating VBScript objects.  For example, network objects, Active Directory objects and also applications such as IE.

e) select-object.  Filters objects based on parameters set in the cmdlet command string

f) group-Object.  An undervalued cmdlet.  Handy for collecting objects based on a common property value.

g) sort-Object.  Sequences object based on a property value

3) Items Built-in Cmdlets

a) get-Childitem Retrieves the child items of the specified location(s), for example a list files in a folder

b) get-Item Returns an object that represents an item in a namespace, for example get-Item .\* lists files in the current directory

c) new-Item Creates a new item in a namespace, for example creates a sub-folder

d) set-Item Sets the value of a pathname within a provider to the specified value

e) remove-Item Deletes an item from a provider

f) move-Item Transfers an item from one location to another, removing the original

g) rename-Item Changes the name of an existing item

h) copy-Item Copies an item from one location to another, leaving the original intact

i) clear-Item Removes the content of an item

j) invoke-Item Invokes an executable or opens a file

k) get-acl Gets the access control list (ACL) associated with a file or item

l) set-acl Sets the security ACL for an item or items

4) Aliases Built-in PowerShell Cmdlets

Understanding Aliases is easy.  Just start with the built-in Aliases, for example gci (get-Childitem).  Also ft (format table) for example, get-Process * |ft name, handles, cpu -auto

a) set-alias Maps an alias to a command, for example where you wish to create your own alias.

b) get-alias Returns a list of all defined aliases

c) new-alias Creates a new alias

d) export-alias Outputs the system alias table in CSV format

e) import-alias Updates the system alias table from a CSV file

5) Drives Built-in Cmdlets

a) Get-psdrive Returns a list of all drives registered with cmdlet providers

b) new-drive Creates a new drive associated with a cmdlet provider

c) get-provider Returns a list of all registered cmdlet providers and the drives associated with each provider

d) remove-drive Removes a drive association from a cmdlet provider

6) Paths and locations

a) get-location Displays the current location

b) set-location Sets the current working location to a specified location (Has the Alias CD)

c) combine-path Combines path elements into a single path

d) convert-path Converts the path to the item given from an MSH path to a provider path

e) parse-path Given an MSH path(s), streams a string with the qualifier, parent path, or leaf item

f) test-path Returns true if the path exists, otherwise returns false

g) resolve-path Resolves the wildcards in a path

h) push-location Pushes a location to the stack

i) pop-location Changes the current working location to the location specified by the last entry pushed onto the stack

7) Contents Built-in PowerShell Cmdlets

a) add-content Appends content to a file or creates a file if one does not exist

b) clear-content Removes content from a file while leaving the file intact

c) get-content Returns the content of a file as a sequence of lines

d) set-content Replaces the content of a file with new content

8)  Access Operating System Components

a) get-Process Returns a list of running system processes

b) stop-process Terminates a running process

c) get-service Returns a list of registered system services

d) stop-service Terminates a running system service

e) start-service Starts a stopped system service

f) suspend-service Pauses a running system service

g) resume-service Reactivates a paused system service

h) restart-service Stops then restarts a system service

i) set-service Configures the properties of a registered system service

j) new-service Registers a new system service

k) get-Eventlog Returns a list of event log entries from a specified event log

l) get-WmiObject Returns data from WMI

9) Output Formatters Built-in Cmdlets

a) out-file Sends output to a file

b) out-printer Sends output to a printer

c) out-string Sends output to a string

d) out-null Drops all output

e) out-default Sends output to the host; not called from the command line

f) out-host Sends output to the host

g) format-list Formats objects as a list of their properties displayed vertically

h) format-Table Formats objects as a tabulated list (one line per object)

i) format-wide Formats objects as a tabulated list (several objects per line)

j) import-csv Generates a sequence of objects from a comma-separated variable file

k) export-csv Writes a sequence of objects to a file in comma-separated form

l) write-host Writes an object to the hosting environment (usually the console)

m) write-progress Writes to the host's progress display channel

n) write-object Writes an object to the pipeline

o) write-debug Writes an object into the debug pipeline

p) write-verbose Writes an object to the host's verbose display channel; output may or may not be shown depending on the host settings

q) write-error Writes an object to the error pipeline

r) read-host Reads data from the hosting environment (usually the console)

10) Variables

a) get-variable Returns the value of a variable

b) new-variable Creates a new variable with a specified name and value

c) set-variable Updates or creates a new variable with a specified name and value; useful at the end of a pipeline for storing objects into a variable for later use

d) remove-variable Removes a variable definition from the variable list

e) clear-variable Removes the value of a variable but leaves its definition in place ( i.e., sets its value to null)

11) Security Built-in Cmdlets

a) get-pfxcertificate Returns an X509Certificate from a file

b) get-credential Generates a credential by asking an interactive user to provide a password

c) get-authenticodesignature Returns the Authenticode signature from a file

d) set-authenticodesignature Updates the Authenticode signature on a file

e) new-securestring Creates a string that can be used to safely store and work with sensitive information (e.g., passwords)f

f) export-securestring Converts a secure string into an encrypted representation in a regular string

g) import-securestring Converts an encrypted string back into a secure string

12) Miscellaneous PowerShell Built-in Cmdlets

a) get-date Returns the current date and time

b) set-date Updates the system date and time

c) match-string Searches through a string or file(s) for a pattern

d) measure-object Calculates arithmetical statistics on specific properties of pipeline objects

e) new-timespan Calculates the time difference between two specified DateTime objects

f) start-sleep Pauses processing for a specified number of seconds or milliseconds

13) Debugging

a) set-mshdebug Enables/disables debugging and execution trace support

b) trace-expression Enables tracing for a specified expression or command

Result of get-command

To get a complete list of all the Aliases, I went to the PS Prompt and typed:

get-command | fw -column 3

Here are the results in three columns:

(fw -column 3 means format the output in three columns.)

Add-Content   Add-History      Add-Member
Add-PSSnapin Clear-Content   Clear-Item
Clear-Item      Property Clear-Variable         Compare-Object
ConvertFrom-SecureString      Convert-Path  ConvertTo-Html
ConvertTo-SecureString         Copy-Item      Copy-ItemProperty
Export-Alias   Export-Clixml      Export-Console
Export-Csv    ForEach-Object  Format-Custom
Format-List    Format-Table     Format-Wide
Get-Acl         Get-Alias           Get-AuthenticodeSignature
Get-ChildItem Get-Command    Get-Content
Get-Credential Get-Culture      Get-Date
Get-EventLog Get-ExecutionPolicy Get-Help
Get-History    Get-Host           Get-Item
Get-ItemProperty Get-Location Get-Member
Get-PfxCertificate Get-Process Get-PSDrive
Get-PSProvider Get-PSSnapin  Get-Service
Get-TraceSource Get-UICulture Get-Unique
Get-Variable   Get-WmiObject   Group-Object
Import-Alias   Import-Clixml      Import-Csv
Invoke-Expression  Invoke-History Invoke-Item
Join-Path      Measure-Command Measure-Object
Move-Item    Move-ItemProperty New-Alias
New-Item New-ItemProperty    New-Object
New-PSDrive New-Service       New-TimeSpan
New-Variable Out-Default       Out-File
Out-Host      Out-Null            Out-Printer
Out-String    Pop-Location      Push-Location
Read-Host    Remove-Item      Remove-ItemProperty
Remove-PSDrive Remove-PSSnapin Remove-Variable
Rename-Item Rename-ItemProperty Resolve-Path
Restart-Service Resume-Service Select-Object
Select-String Set-Acl             Set-Alias
Set-AuthenticodeSignature     Set-Content Set-Date
Set-ExecutionPolicy Set-Item  Set-ItemProperty
Set-Location Set-PSDebug      Set-Service
Set-TraceSource Set-Variable Sort-Object
Split-Path    Start-Service      Start-Sleep
Start-Transcript Stop-Process Stop-Service
Stop-Transcript Suspend-Service Tee-Object
Test-Path    Trace-Command  Update-FormatData
Update-TypeData Where-Object Write-Debug
Write-Error   Write-Host         Write-Output
Write-Progress Write-Verbose  Write-Warning

Summary of PowerShell's Built-in cmdlets

PowerShell has a rich source of built-in verb-noun pairs.  While you probably only need about 20, it's worthwhile acquainting yourself with what commands are available.  Guy says waste no opportunity to increase your cmdlet repertoire.

See Also

• Windows PowerShell Home  • Introduction  • Cmdlets  • Exchange 2007  • Profile.ps1  • $_.Pipeline

If you see an error of any kind, do let me know.  Please report any factual mistakes, grammatical errors or broken links, I will be happy to not only to correct the fault, but also to give you credit.

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