----------------------------------------------------------------------
  ^                        the beginning of the string
----------------------------------------------------------------------
  0                        '0'
----------------------------------------------------------------------
  .                        any character except \n
----------------------------------------------------------------------
  00000                    '00000'
----------------------------------------------------------------------

##</code><code>##

use warnings;
use strict;

my @cols = qw(3.456 8.903 1.223);
@cols = map { sprintf '%8.1f', $_ } @cols;
print "@cols\n";

__END__

     3.5      8.9      1.2