Not able to show help for flags of a command in PowerShell

Question

I'm a verbose person so I usually create a new directory without using aliases like this.

New-Item Donkey -ItemType d

A less verbose colleague nagged about it and, since I'm such a pleasure and joy to work with, I thought I'll short it down, because I want the unverbose people to be content too. So I went like this.

ni Donkey -ItemType d

Then, something hit me and I tried the following, just for the fun of it, fully expecting to get the slap telling me to go and do stuff to myself.

ni Donkey -it d

Wouldn't you know? It actually worked! So, happy about making everything totally cryptic for my verbality aversed friend, I started to investigate what else I could abbreviate. I went like this.

Get-Help ni
Get-Help it

Whereas the first one gave me the command including it's alias, just as expected, the second one barked at me telling me there's no such thing. Well, I beg its pardon but I just executed the command so I know there is.

After a few "There's too! There's not. There's too! There's not." I realized that I'm not going to win against the stubborn, red message of PowerShell. So, here's my questions.

Is it an alias to begin with?
How can I get help on it (be that alias or something else)?

@t1meless is correct (and should post this as an answer). "it" is not an alias, it is a short way to write the parameter and only works because no other parameter for this cmdlet shares the same prefix. You can shorten this parameter to "i", since it is the only parameter for the cmdlet to start with this letter. Get-Help it does not yield a result because Get-Help returns information for cmdlets, not parameters. More here, http://stackoverflow.com/questions/7262802/shorter-versions-of-powershell-cmdlet-parameters — root, Oct 22 '16 at 14:40
@t1meless Hehe, I see it now. I got fooled by the capitalization of ItemType and missed that it is both that and the prefix. Great info. Also, the flag -full will be useful. You should definitely post it as an answer. — Konrad Viltersten, Oct 22 '16 at 16:44

Peter Hahndorf · Accepted Answer · 2016-10-22T16:55:31.140

2

In PowerShell we have two types of Aliases, for cmdLets/functions and for parameters.

Get-Alias shows the defined aliases for CmdLets/Functions

To see the aliases for parameters for New-Item you can use:

(gcm -Name New-Item).parameters.values | ? { $_.aliases } | ft name, aliases

You get:

Name         Aliases
----         -------
ItemType     {Type}
Value        {Target}
Verbose      {vb}
Debug        {db}
ErrorAction  {ea}
...

So you could use:

New-Item Donkey -Type d

because Type is an alias for ItemType

the fact that -it works has already been explained in the comments, for parameters you can specify the unique first few letters of the parameter name.

the shortest way to create a directory is:

md Donkey

md is an alias for mkdir which in turn is a function that uses New-Item -ItemType Directory

If you need to see parameter aliases without remembering the long command above, put the following into your PowerShell profile:

function Get-ParameterAlias([string]$cmd)
{
    (gcm -Name $cmd).parameters.values | ? { $_.aliases } | ft name, aliases
}
Set-Alias -Name gpa -Value Get-ParameterAlias

Now you can just use: gpa New-Item to get its parameter aliases

edited Oct 22 '16 at 16:55

answered Oct 22 '16 at 16:34

Peter Hahndorf

13,710

I see the command but it's way to complex to be useful in my case. I use PowerShell intensively but only occasionally, so I need something that's very intuitive, regrettably. Nevertheless, +1 for a great answer. – Konrad Viltersten Oct 22 '16 at 16:45
@KonradViltersten not too complex for your case at all. Just store the function in your PowerShell Profile http://www.howtogeek.com/50236/customizing-your-powershell-profile/ and then just use the function like this in your PowerShell Console Get-ParameterAlias -cmd New-Item – SimonS Oct 23 '16 at 21:35
@SimonS That's far above my current PowerShell-fu. I look forward to get it under control though. Thanks for the link. It will come in handy. :) – Konrad Viltersten Oct 23 '16 at 22:29
@KonradViltersten fyi: there's one small error in the link i provided. don't use test-path $profile to locate your profile because on my computer it returns false even tough i have a profile. just use $profile without the test-path to locate the profile. – SimonS Oct 24 '16 at 07:08
@SimonS Haven't had time to take a loot at it yet because my system dies after the latest Win 10 upgrade (I'm crying about it here, hehe). But I do appreciate your agility. – Konrad Viltersten Oct 24 '16 at 08:12

Not able to show help for flags of a command in PowerShell

1 Answers1