How to find out if a script is ran, or dot-sourced?

Question

This came up in a little thing I was working on... I'd like to be able to detect if a script is being ran "cold", or if it's being dot-sourced. I've had a good search but no luck so far.
eg, if a script can detect whether it's being ran as
.\myscript.ps1
or
. .\myscript.ps1
Not looking for a "what are you trying to do, maybe do it this way instead" sorta deal - this is more of a curio, wondering if it can actually be done.
Anyone?
A

Answer 1

Get-PSCallStack is another excellent way to determine this as well and also works great to determine what file a function came from. You can get some great info from it as shown below.
$ScriptStack = (Get-PSCallStack)
Write-Verbose ("Is DotSourced? -- {0}" -f ($ScriptStack[1].position.text -match '^\.\s\.')) -Verbose
Function Foo {
$FunctionStack = (Get-PSCallStack)
Write-Verbose "Originating Script for $($FunctionStack[0].Command): $($FunctionStack[0].ScriptName)" -Verbose
Write-Verbose "Originating Command calling $($FunctionStack[0].Command): $($FunctionStack[1].Command)" -Verbose
Function Main {
$FunctionStack = (Get-PSCallStack)
Write-Verbose "Originating Script for $($FunctionStack[0].Command): $($FunctionStack[0].ScriptName)" -Verbose
FOO
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