Write-Output "`$PSCommandPath: $PSCommandPath";
In previous snippet of PowerShell note the use of the Grave accent character before $PSCommandPath (e,.g. `$PSCommandPath). This escape character suppresses $PSCommandPath being interpreted as a variable and instead prints the string literal. For those who cannot find the grave accent (it is to the left of the 1 key or as http://soinoticedthis.blogspot.com/ shows in one blog post):
Displaying the drive letter is a matter of executing (script file, ShowDriveLetter.ps1):
$DriveLetter = $PSCommandPath[0];
Write-Output "Drive Letter: $DriveLetter";
The output from this is as follows:
The $PSCommandPath automatic variable will not work if you are using PowerShell 2. This version of PowerShell is native to Windows 7 and Windows Server 2008 R2. PowerShell 2 is available in Windows XP upgrade to Service Pack 3, Windows Server 2003 upgraded to Service Pack 2 and Windows Vista upgraded to Service Pack 1.
If you are limited to PowerShell 2 consider the following (script: ShowPathInfoPowerShell2.ps1):
function WhatHappensNestedInAFunction()
{
Write-Output("Function invoked `$MyInvocation.ScriptName: " +
$MyInvocation.ScriptName);
Write-Output("Function invoked `$MyInvocation.Path: " +
$MyInvocation.MyCommand.Path);
}
Write-Output("Script invoked `$MyInvocation.ScriptName: " +
$MyInvocation.ScriptName);
Write-Output("Script invoked `$MyInvocation.Path: " +
$MyInvocation.MyCommand.Path);
WhatHappensNestedInAFunction ;
The output from the script is as follows:
This means in PowerShell 2 you have to use the following to get the script name within the script:'s body:
$MyInvocation.MyCommand.Path
It also means in PowerShell 2 you have to use the following to get the script name within a function:
$MyInvocation.ScriptName
To simplify this, it is simpler to just create a function that uses $MyInvocation.ScriptName to return the script path:
function GetScriptPath()
{
return $MyInvocation.ScriptName;
}
Once the script path is know, getting the driver letter is trivial (as was previously demonstrated).
