I picked up Jerry Lee Ford’s book Microsoft Windows PowerShell Programming for the absolute beginner . 

In the section on aliases, he warns users that Set-Alias does not verify the validity of the alias assignment.  That is a good point.  Here is a function that does that for you. 

function Set-Alias-Strict($Name, $Value)
{
    $null = Get-Command $Value
    Set-Alias $Name $Value   
}
Set-Alias sals Set-Alias-Strict

Here is that function in action:

PS> Set-Alias        test Get-Porcess
PS> Set-Alias-Strict test Get-Porcess
Get-Command : The term ‘Get-Porcess’ is not recognized as a cmdlet, functio
n, operable program, or script file. Verify the term and try again.
At line:3 char:24
+     $null = Get-Command  <<<< $Value
PS> Set-Alias-Strict test Get-Process
PS>

 I transpose characters on a fairly frequent basis so this is a good thing for me to use.  Of course I don’t want to type all that so the alias comes in handy:

PS> sals test Get-Porcess
Get-Command : The term ‘Get-Porcess’ is not recognized as a cmdlet, functio
n, operable program, or script file. Verify the term and try again.
At line:3 char:24
+     $null = Get-Command  <<<< $Value
PS> sals test Get-Process
PS>

Notice the naming model I used.  If there is a command that doesn’t have the functions you want it to have, I recommend the naming scheme here (this was first suggested by Lee Holmes).  Create a new name by taking the old name and concatenating a “-” and a word.  (e.g. “-Strict” ).  This makes it easier to find and understand.

PS> gcm *-alias*

CommandType     Name                          Definition
———–     —-                          ———-
Cmdlet          Export-Alias                  Export-Alias [-Path] <Stri…
Cmdlet          Get-Alias                     Get-Alias [[-Name] <String…
Cmdlet          Import-Alias                  Import-Alias [-Path] <Stri…
Cmdlet          New-Alias                     New-Alias [-Name] <String>…
Cmdlet          Set-Alias                     Set-Alias [-Name] <String>…
Function        Set-Alias-Strict              param($Name, $Value) $null…

PS>

Enjoy! 

Jeffrey Snover [MSFT]
Windows PowerShell/MMC Architect
Visit the Windows PowerShell Team blog at:    http://blogs.msdn.com/PowerShell
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