use File::Basename qw/ dirname basename /;
use File::Find::Rule;

my $rule = rule( file => start => '/data/input' );

while(my $path = $rule->match) {
  printf "%s,%s,%s\n", dirname($path), basename($path), -s $path;
}

##</code><code>##

## do same 'use's as above
printf "%s,%s,%s\n", dirname($_), basename($_), -s $_
  for find( file => in => '/data/input' );