#!/usr/bin/perl

@snapshots=`zfs list -t snapshot`;

$kilo = 1024;
$mega = 1024 * 1024;
$giga = 1024 * 1024 * 1024;
$maxlen = 0;

sub adjust_size
{
  my ($size) = @_;
  if($size > ($giga)) { $size = $size / $giga; $size = sprintf("%2.2fG",$size); }
  elsif($size > ($mega)) { $size = int($size / $mega); $size = "$size"."M"; }
  elsif($size > ($kilo)) { $size = int($size / $kilo); $size = "$size"."K"; }
  return $size;
}

foreach $snapshot (@snapshots)
{
  chomp($snapshot);
  if($snapshot =~ /(\S+)\@(\S+)\s+(\S+)\s+/) {
    $filesystem = $1;
    $size = $3;
    if(length($filesystem) > $maxlen) { $maxlen = length($filesystem); }
    if($size =~ /k/i) { $size = $size * $kilo; }
    if($size =~ /m/i) { $size = $size * $mega; }
    if($size =~ /g/i) { $size = $size * $giga; }
    $totals{$filesystem}{size} += $size;
    $totals{$filesystem}{snapshots}++;
  }
}

$maxlen=$maxlen+2;
printf "%-${maxlen}s %-15s %-10s\n","ZFS Filesystem","Snapshots Size","Num Snapshots";
printf "%-${maxlen}s %-15s %-10s\n","--","--","--";
foreach $key (sort keys %totals)
{
  $size = $totals{$key}{size};
  $total_size += $size;
  $total_snapshots += $totals{$key}{snapshots};
  $size = &adjust_size($size);
  printf "%-${maxlen}s %-15s %-10s\n", $key, $size, $totals{$key}{snapshots};
}

$total_size = &adjust_size($total_size);
printf "%-${maxlen}s %-15s %-10s\n","--","--","--";
printf "%-${maxlen}s %-15s %-10s\n","Total Snapshots",$total_size,$total_snapshots;