#!/usr/bin/perl -w
use strict;
use Getopt::Std;
use File::Find;

my %opt;
@ARGV > 0 and getopts('n:s:m:', \%opt) and not (keys %opt > 1) or die << "USAGE";
Shows the biggest files residing in one or several directory trees.
usage: $0 [-n num] [-t size] [-m size] directory [directory ...]
       -n  show <num> files
       -s  show biggest files totalling <size>
       -m  show all files bigger than <size>
       use only one option at a time
       default is 20 biggest files
USAGE
my ($switch, $param) = %opt;

my %size;
find(sub {$size{$File::Find::name}=-s if -f;}, @ARGV);
my @sorted = sort {$size{$b} <=> $size{$a}} keys %size;

my $maxidx = 0;
if($switch eq 's') {
    ($param -= $size{$_}) >= 0 ? $maxidx++ : last for @sort;
}
elsif($switch eq 'm') {
    $size{$_} < $param ? $maxidx++ : last for @sort;
}
else {
    $maxidx = ($val || 20) - 1;
}
   
printf "%10d $_\n", $size{$_} for @sorted[0 .. $maxidx];