#!/usr/bin/perl -w

my @un = <DATA>;
print "once:\n";
print sort { lc($a) cmp lc($b) } @un;
print "\nagain:\n";
print sort { (lc($a) cmp lc($b)) or ($a cmp $b) } @un;

__DATA__
Mark
MARK
mark
Dave
DAVE
DAVEY
Davey
davey
MarkY