I was working with a simple script, that unexpectedly broke.  The 
problem can be reduced to this:

pete@robots:~$ cat t.rb
#!/usr/bin/env ruby
p gets
pete@robots:~$ ./t.rb
asdf
"asdf\n"
pete@robots:~$ ./t.rb nonexistent-file
./t.rb:2:in `gets': No such file or directory - nonexistent-file 
(Errno::ENOENT)
         from ./t.rb:2

Ah, right, I remember this from the Bad Old Days of Perl: stdin has been 
stolen.  Is there any way to stop this behavior, like a global I could 
set or a flag I could pass to ruby?  Couldn't find anything on the man 
page or in Pickaxe.