I must have forgotten something dreadfully simple.
How do I limit input (from stdin in this case) so that the first non  
AlphaNumeric ends input?
I fiddled with gets and with $/ to no avail.
I know I could do input validation later, and I could (should)  
normally use buffered input.
gets uses the default \n to end input.
I'd like to end it at the first non-alpha-numeric.
(Ideally, eventually a language specific version would be beautiful  
to handle unicode codepoint ranges similarly)

Any ideas?
Or a method that I'm just missing?