TRAPALRM / TMOUT oddity

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

Consider:

% TRAPALRM() { print TIME IS UP; exit 1 }
% TMOUT=5

You'd expect the shell to exit in 5 seconds, but instead what happens is
that TIME IS UP is printed every 5 seconds until any key is pressed, at
which point the shell exits.

The same behavior occurs when using "trap".