Calling a powershell function using a .bat file - powershell

Question

I would like to know how to call a powershell function using a .Bat file.
I have this simple function:
(Script.ps1)
function testfunction
{
Write-Log "Calling from Bat file"
}
and I would like to call the function testfunction within the .Bat File.
powershell .\Script.ps1 ...

Answer 1

I noticed that there is a switch -ExecutionPolicy ByPass which allows the batch file to run using Powershell. This works here, taken from the answer by vonPryz.
#echo off
:: Create a test script file
echo function test { write-host "Called from %~f0" } > s.ps1
powershell -ExecutionPolicy ByPass -command ". "%cd%\s.ps1"; test;"
del s.ps1
pause

Answer 2

Start Powershell with -command switch, include the script and call the function. You need to dot source the script before its function can be called.
:: Create a test script file
C:\temp>echo function test { write-host "Called from .bat" } > c:\temp\s.ps1
C:\temp>powershell -command ". c:\temp\s.ps1; test;"
:: Output
Called from .bat
Also, take a look at some samples.

Answer 3

I know this is very old but I was recently trying to do this same thing and it took me a long time to find out what to do. The answer is amazingly simple
In BatchFile (RunMe)
powershell -command ". Script.ps1; Set-SomeFunction %1 %2 %3 %4 %5"
Then you can call the batch like
RunMe -SomeParm val -SomeParm2 val -SomeSwitch -SomeBool $true
also, to run as admin
powershell -command "Start-Process -verb runas powershell" "'-noexit -command ". Script.ps1; Set-SomeFunction %1 %2 %3 %4 %5 %6 %7 %8 %9'"

Answer 4

I usually do it like that:
powershell {Set-ExecutionPolicy unrestricted}
powershell.exe -executionpolicy ByPass ./script/powerhsell-script.ps1 %par1% %par2%
powershell {Set-ExecutionPolicy Restricted}
Hope you need that :)

Answer 5

I've done it using
powershell.exe -ExecutionPolicy Bypass -file ".\Write_date.ps1"
Seems similar to what others have written but I'm not sure what vonPryz meant by needing the dot source the script before calling the script. The above worked on a Win7 with executionpolicy set to restricted.