A One-line primality test

A primality test in one line of Perl:

perl -wle 'print "Prime" if (1 x shift) !~ /^1?$|^(11+?)\1+$/' [number]

Originally written by Abigail. Explained in detail by Neil Kandalgaonkar. Kudos to Pete Warden for the link.

Written on November 9, 2013