BiosBreaker

There's nothing more about it. You can break out of the parallel.waitForAny, and execute code at the last line of the bios. (os.shutdown)

Pastebin:

pastebin get Fjv0RdAy break

Usage:

break <absolute path to program> [optional parameter(s)]

Yes, I know that there are some bios-breaking (that's how I call breaking out of the parallel.waitForAny) programs, but this one is a bit different. Look at the last line of the program :D/> Fancy, isn't it?

I did something much similar that would overwrite printError, queue a terminate event, and when the bios went to print the error it'd run your code–making it TLCO. This method is a lot simpler, and is a lot shorter.

I'm guessing this is some form of TLCO. If so, this code might be a little simpler…

local pullEvent, shutdown = os.pullEventRaw, os.shutdown
function os.shutdown()
    os.shutdown = shutdown
    os.pullEventRaw = pullEvent
    -- custom code
end
os.pullEventRaw = nil

Also, you seem to misunderstand how loadfile() works.

local f, err = loadfile( file )
if f then -- file loaded - no syntax errors
    f()
else -- syntax error in file
    printError( err )
end