[luatex] How do you exit luatex?

[Michael Kropat]

I'm playing around with switching from xetex to luatex. On my first 
attempt to invoke luatex, I encountered this peculiar behavior:

     $ luatex no-such-file.tex
     This is LuaTeX, Version beta-0.76.0-2013061708 (rev 4627)
     restricted \write18 enabled.
     ! I can't find file `no-such-file.tex'.
     <*> no-such-file.tex

     Please type another input file name: ^C! I can't find file 
`no-such-file'.
     <*> no-such-file.tex

     Please type another input file name:

How do I break out of this loop?

I'm encountering this behavior using the TeX Live 2013 version of 
luatex, running under Linux Mint.

Michael