Powershell Cmdlet with Mandatory Parameters

Question

I'm trying to create a simple powershell cmdlet that would have a few mandatory parameters. I've found the following code for doing so however, I cannot get it to execute:

function new-command() {
    [CmdletBinding()]
    PARAM (
        [Parameter(Mandatory=$true)]
        [string]$Name
    )
}

new-command

Returns the following error:

Missing closing ')' in expression." Line: 5 Char: 3 + [ <<<< string]$Name

What am I doing wrong?

Yep. Throws an error if I don't include an argument after new-command, and quietly does nothing if I do. — mjolinor, Jun 22 '11 at 00:06

score 10 · Answer 1 · answered Jun 22 '11 at 05:06

10

The explanation is that you are running this script in PowerShell V1.0 and these function attributes are supported in PowerShell V2.0. Look at $host variable for you PowerHhell version.

answered Jun 22 '11 at 05:06

JPBlanc

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score 1 · Answer 2 · answered Jun 22 '11 at 04:20

1

Try this instead:

function new-command {
    [CmdletBinding()]
    PARAM (
        [Parameter(Mandatory=$true)]
        [string]$Name
    )
}

new-command

You don't need parentheses after the function name.

answered Jun 22 '11 at 04:20

JoeG

4,117
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His code works in PowerShell V2.0, but not in V1.0. In V1.0 the code gives exactly the error discribed – JPBlanc Jun 22 '11 at 05:07

score 1 · Answer 3 · answered Jun 22 '11 at 14:57

In PS 2.0 mandatory parameters are controlled through the CmdLetBinding and Parameter attributes as shown in the other answers.

function new-command {
    [CmdletBinding()]
    PARAM (
        [Parameter(Mandatory=$true)]
        [string]$Name
    )
    $Name
}

new-command

In PS 1.0 there are not direct constructs for handling mandatory attributes but you can for example throw an error if a mandatory parameter hasn't been supplied. I often use the following construct.

function new-command {
    param($Name=$(throw "Mandatory parameter -Name not supplied."))
    $Name
}

I hope this helps.

score 1 · Answer 4 · edited May 23 '17 at 10:30

1

You'll have the same error message even with Powershell v2.0 if Param(...) hasn't been declared at the beginning of the script (exclude comment lines). Please refer to powershell-2-0-param-keyword-error

edited May 23 '17 at 10:30

Community

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answered Feb 07 '12 at 13:52

Jing Li

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score 0 · Answer 5 · edited Nov 26 '18 at 05:57

0

Try below syntax and also kindly check whether have missed any double quotes or brackets.

Param([parameter(Mandatory=$true, HelpMessage="Path to file")] $path)

edited Nov 26 '18 at 05:57

NIMISHAN

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answered Nov 26 '18 at 04:53

kalaivani

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Powershell Cmdlet with Mandatory Parameters

5 Answers5