PowerShell Logo Small

about_requires



This is the built-in help made by Microsoft for the document 'about_requires', in PowerShell version 2 - as retrieved from Windows version 'Microsoft® Windows Vista™ Ultimate ' PowerShell help files on 2016-06-24.

For PowerShell version 3 and up, where you have Update-Help, this command was run just before creating the web pages from the help files.

Search powershellhelp.space

TOPIC
about_Requires

SHORT DESCRIPTION
Prevents a script from running by requiring the specified snap-ins and
version.

LONG DESCRIPTION
The #Requires statement prevents a script from running unless the Windows
PowerShell version, snap-in, and snap-in version prerequisites are met. If
the prerequisites are not met, Windows PowerShell does not run the script.

You can use #Requires statements in any script. You cannot use them in
functions, cmdlets, or snap-ins.


Syntax

Use the following syntax to specify the snap-in and the version of the
snap-in that you want to require:

#requires –PsSnapIn <PsSnapIn> [-Version <N>[.<n>]]


Use the following syntax to specify the minimum version of
Windows PowerShell that you want to require:

#requires -Version <N>[.<n>]


Use the following syntax to specify the shell that you want to require:

#requires –ShellId <ShellId>


Rules for Use

- The #Requires statement must be the first item on a line in a script.

- A script can include more than one #Requires statement.

- The #Requires statements can appear on any line in a script.


Examples

The following statement requires the Microsoft.PowerShell.Security
snap-in:

#requires –PsSnapIn Microsoft.PowerShell.Security


If the Microsoft.PowerShell.Security snap-in is not loaded, the script
does not run, and Windows PowerShell displays the following error
message:

"The script '<script-name>' cannot be run because the following
Windows PowerShell snap-ins that are specified by its "#requires"
statements are missing: Microsoft.PowerShell.Security."


The following statement requires the Windows PowerShell 2.0 version or
any later version of the Microsoft.PowerShell.Security snap-in:

#requires –PsSnapIn Microsoft.PowerShell.Security –Version 2


The following statement requires Windows PowerShell 2.0 or a later
version:

#requires –Version 2.0


The following script has two #Requires statements. The requirements
specified in both statements must be met. Otherwise, the script will not
run. Each #Requires statement must be the first item on a line:

#requires –PsSnapIn Microsoft.PowerShell.Security –Version 2
Get-WMIObject WIN32_LogicalDisk | out-file K:\status\DiskStatus.txt
#requires –Version 2


The following #Requires statement prevents a script from running if the
specified shell ID does not match the current shell ID. The current
shell ID is stored in the $ShellId variable:

#requires –ShellId MyLocalShell
about_Automatic_Variables
about_Language_Keywords
about_PSSnapins
get-PSSnapin