A couple of minor golfish things, without really changing the algorithm:
sub ruler {
my $n = 9 + shift; chop $n;
join "", " ", map(" "x(9-/../).$_, 1..$n), "\n",
"0123456789" x $n, "0\n"
}
But for filling exactly to (arg) columns (eg, to avoid wrapping when using $ENV{COLUMNS}):
sub ruler {
my $n = shift;
join"", " ", map(" "x(9-/../).$_, 1..$n/10), "\n",
map(/.$/g, 0..$n), "\n"
}
update: or (of course) ye olde one-liner:
perl -lwe 'print" ",map(" "x(9-/../).$_,1..$ARGV[0]/10),"\n",map/.$/g,0..shift'
further
update:
chipmunk got it. He's almost using printf as a map!
p