2/25    Why are only four bytes guaranteed for ungetc?
        \_ according to K&R, only one char is guaranteed.
        \_ getc/ungetc is a fundamentally broken paradigm like
           many other unix APIs.  If four bytes are guaranteed
           on your particular OS, it's proably because the dumbass
           implementing this stuff has a 32-bit word that he's using
           as a shift register to spool characters into.
        \_ As the above says, your 4 bytes are specific to the system
           you're on.  You should only count on one byte guaranteed.