one-liner wars

n. A game popular among hackers who code in the language APL (see write-only
language and line noise ). The objective is to see who can code the most
interesting and/or useful routine in one line of operators chosen from APL's
exceedingly hairy primitive set. A similar amusement was practiced among
TECO hackers and is now popular among Perl aficionados. Ken Iverson, the
inventor of APL, has been credited with a one-liner that, given a number N ,
produces a list of the prime numbers from 1 to N inclusive. It looks like
this: (2=0+.=T. |T)/T N Here's a Perl program that prints primes: perl -wle
'(1 x $_) !~ /^(11+)\1+$/ print while ++ $_' In the Perl world this game is
sometimes called Perl Golf because the player with the fewest (key)strokes
wins.