Running a function from a powershell script from the command line

Question

Rather than creating several scripts each with one function, I have one script with has several functions.... I would like to call the script and select the function i want to use from the command line.
so far, if i change directory to that of the script i can call the function by doing this:
cd c:\myscripts
. .\mytestscript.ps1; myfunction
this works fine.... i have also tried, what I would like to achieve is calling it like this
c:\myscripts\mytestscript.ps1; myfunction
however, i am trying to run this as part of an MDT task sequence, my command line looks like this and using the ; myfunction at the end doesn't work.
powershell.exe -ExecutionPolicy Bypass %SCRIPTROOT%\CustomScripts\mytestscript.ps1; myfunction
how can i adapt my command line so that it will successfully call the function within my script?
thanks
Steve

Answer 1

Rename the file from ps1 to psm1 and create a powershell module that contain multiple functions. A module will autoload like the built-in modules.
Placement of the psm1 file is important for Powershell to find and autoload it.
The file name and folder name must be the same, for example MyModule.psm1 should be in the folder:
user\documents\windowspowershell\modules\mymodule
Windows PowerShell Modules
http://msdn.microsoft.com/en-us/library/dd878324(v=vs.85).aspx
PS C:\> get-childItem env:PSModulePath
Name Value
PSModulePath C:\Users\User\Documents\WindowsPowerShell\Modules;C:\Windows\system32\WindowsPowerShell\v1.0\Modules\