Getting information about commands

The PowerShell Get-Command displays commands that are available in your current session. When you run the Get-Command cmdlet, you see something similar to the following output:

CommandType     Name                    Version    Source
-----------     ----                    -------    ------
Cmdlet          Add-Computer            3.1.0.0    Microsoft.PowerShell.Management
Cmdlet          Add-Content             3.1.0.0    Microsoft.PowerShell.Management
Cmdlet          Add-History             3.0.0.0    Microsoft.PowerShell.Core
Cmdlet          Add-JobTrigger          1.1.0.0    PSScheduledJob
Cmdlet          Add-LocalGroupMember    1.0.0.0    Microsoft.PowerShell.LocalAccounts
Cmdlet          Add-Member              3.1.0.0    Microsoft.PowerShell.Utility
Cmdlet          Add-PSSnapin            3.0.0.0    Microsoft.PowerShell.Core
Cmdlet          Add-Type                3.1.0.0    Microsoft.PowerShell.Utility
...

This output looks a lot like the Help output of cmd.exe: a tabular summary of internal commands. In the excerpt of the Get-Command command output shown above, every command shown has a CommandType of Cmdlet. A cmdlet is PowerShell's intrinsic command type. This type corresponds roughly to commands like dir and cd in cmd.exe or the built-in commands of Unix shells like bash.

The Get-Command cmdlet has a Syntax parameter that returns syntax of each cmdlet. The following example shows how to get the syntax of the Get-Help cmdlet:

Get-Command Get-Help -Syntax
Get-Help [[-Name] <String>] [-Path <String>] [-Category <String[]>] [-Component <String[]>] [-Functionality <String[]>]
 [-Role <String[]>] [-Full] [-Online] [-Verbose] [-Debug] [-ErrorAction <ActionPreference>] [-WarningAction <ActionPreference>] [-ErrorVariable <String>] [-WarningVariable <String>] [-OutVariable <String>] [-OutBuffer <Int32>]

Get-Help [[-Name] <String>] [-Path <String>] [-Category <String[]>] [-Component <String[]>] [-Functionality <String[]>]
 [-Role <String[]>] [-Detailed] [-Online] [-Verbose] [-Debug] [-ErrorAction <ActionPreference>] [-WarningAction <ActionPreference>] [-ErrorVariable <String>] [-WarningVariable <String>] [-OutVariable <String>] [-OutBuffer <Int32>]

Get-Help [[-Name] <String>] [-Path <String>] [-Category <String[]>] [-Component <String[]>] [-Functionality <String[]>]
 [-Role <String[]>] [-Examples] [-Online] [-Verbose] [-Debug] [-ErrorAction <ActionPreference>] [-WarningAction <ActionPreference>] [-ErrorVariable <String>] [-WarningVariable <String>] [-OutVariable <String>] [-OutBuffer <Int32>]

Get-Help [[-Name] <String>] [-Path <String>] [-Category <String[]>] [-Component <String[]>] [-Functionality <String[]>]
 [-Role <String[]>] [-Parameter <String>] [-Online] [-Verbose] [-Debug] [-ErrorAction <ActionPreference>] [-WarningAction <ActionPreference>] [-ErrorVariable <String>] [-WarningVariable <String>] [-OutVariable <String>] [-OutBuffer <Int32>]

Displaying available command by type

The Get-Command command lists only the cmdlets in the current session. PowerShell actually supports several other types of commands:

  • Aliases
  • Functions
  • Scripts

External executable files, or files that have a registered file type handler, are also classified as commands.

To get all commands in the session, type:

Get-Command *

This list includes external commands in your search path so it can contain thousands of items. It is more useful to look at a reduced set of commands.

Note

The asterisk (*) is used for wildcard matching in PowerShell command arguments. The * means "match one or more of any characters". You can type Get-Command a* to find all commands that begin with the letter "a". Unlike wildcard matching in cmd.exe, PowerShell's wildcard will also match a period.

Use the CommandType parameter of Get-Command to get native commands of other types. cmdlet.

To get command aliases, which are the assigned nicknames of commands, type:

Get-Command -CommandType Alias

To get the functions in the current session, type:

Get-Command -CommandType Function

To display scripts in PowerShell's search path, type:

Get-Command -CommandType Script