#! /usr/bin/perl

use strict;
use warnings FATAL => 'all';
use POSIX 'ceil';
use CGI ':standard';

my $currentpage = param('p') || 1;

if (invalidpage()) {
  die "You've asked for something out of range";
}

outputpage();

{
  my $firstonpage;
  sub firstonpage {
    return $firstonpage
      if defined $firstonpage;
    my $offset = pagesize() - 1;
    $firstonpage = ($currentpage * pagesize()) - $offset;
    return $firstonpage;
  }
}

{
  my $lastonpage;
  sub lastonpage {
    return $lastonpage
      if defined $lastonpage;
    $lastonpage = ($currentpage * pagesize());
    return $lastonpage;
  }
}

sub previouspage {
  $currentpage == firstpage()
    ? undef
    : $currentpage - 1;
}

sub nextpage {
  $currentpage == lastpage()
    ? undef
    : $currentpage + 1;
}

{
  my @range;
  sub getrange {
    return @range if scalar @range;
    my $curpos = tell(DATA);
    local $. = 0;
    while (<DATA>) {
      $. <= lastonpage() and $. >= firstonpage()
        ? push @range, $_
        : next;
    }
    seek(DATA, $curpos, 0);
    return @range;
  }
}

sub outputpage {
  do {
    printheader();
    printrange();
    printnavline();
  } or die $!;
}

sub printheader {
  print header;
  print start_html(
    -title => 'pager',
    -style => 'body { font-family: courier, monospace; }'
  );
  print "~----4NoVyM0U5*m0Nk----~", br();
}

sub printrange {
  for (@{[getrange()]}) {
    print $_, br()
  }
}

sub printnavline {
  if (previouspage()) {
    print a({-href => '?p=' . previouspage()},'&lt;');
  }
  else {
    print '&nbsp;';
  }
  print '&nbsp;' x 22;
  print a({-href => '?p=' . nextpage()},'&gt;')
    if nextpage();
  print $/;
  print end_html;
}

sub invalidpage {
  my $c = $currentpage;
  if ($c < firstpage() || $c > lastpage()) {
    return 1;
  }
  else {
    return 0;
  }
}

sub pagesize { 10 }

sub firstpage { 1 }

{
  my $lastpage;
  sub lastpage {
    return $lastpage
      if defined $lastpage;
    $lastpage = ceil(numberofentries() / pagesize());
    return $lastpage;
  }
}

{
  my $numberofentries;
  sub numberofentries {
    return $numberofentries
      if defined $numberofentries;
    local $. = 0;
    my $curpos = tell(DATA);
    while (<DATA>) { next }
    seek(DATA, $curpos, 0);
    $numberofentries = $.;
    return $numberofentries
  }
}

# NOTE THE GUY SAYS HE WANTS IT
# IN A TEXT FILE:
__DATA__
001 Xxxxxxxxxxxxxxxxxxxx
002 xXxxxxxxxxxxxxxxxxxx
003 xxXxxxxxxxxxxxxxxxxx
004 xxxXxxxxxxxxxxxxxxxx
005 xxxxXxxxxxxxxxxxxxxx
006 xxxxxXxxxxxxxxxxxxxx
007 xxxxxxXxxxxxxxxxxxxx
008 xxxxxxxXxxxxxxxxxxxx
009 xxxxxxxxXxxxxxxxxxxx
010 xxxxxxxxxXxxxxxxxxxx
011 xxxxxxxxxxXxxxxxxxxx
012 xxxxxxxxxxxXxxxxxxxx
013 xxxxxxxxxxxxXxxxxxxx
014 xxxxxxxxxxxxxXxxxxxx
015 xxxxxxxxxxxxxxXxxxxx
016 xxxxxxxxxxxxxxxXxxxx
017 xxxxxxxxxxxxxxxxXxxx
018 xxxxxxxxxxxxxxxxxXxx
019 xxxxxxxxxxxxxxxxxxXx
020 xxxxxxxxxxxxxxxxxxxX
021 xxxxxxxxxxxxxxxxxxXx
022 xxxxxxxxxxxxxxxxxXxx
023 xxxxxxxxxxxxxxxxXxxx
024 xxxxxxxxxxxxxxxXxxxx
025 xxxxxxxxxxxxxxXxxxxx
026 xxxxxxxxxxxxxXxxxxxx
027 xxxxxxxxxxxxXxxxxxxx
028 xxxxxxxxxxxXxxxxxxxx
029 xxxxxxxxxxXxxxxxxxxx
030 xxxxxxxxxXxxxxxxxxxx
031 xxxxxxxxXxxxxxxxxxxx
032 xxxxxxxXxxxxxxxxxxxx
033 xxxxxxXxxxxxxxxxxxxx
034 xxxxxXxxxxxxxxxxxxxx
035 xxxxXxxxxxxxxxxxxxxx
036 xxxXxxxxxxxxxxxxxxxx
037 xxXxxxxxxxxxxxxxxxxx
038 xXxxxxxxxxxxxxxxxxxx
039 Xxxxxxxxxxxxxxxxxxxx
040 xXxxxxxxxxxxxxxxxxxx
041 xxXxxxxxxxxxxxxxxxxx
042 xxxXxxxxxxxxxxxxxxxx
043 xxxxXxxxxxxxxxxxxxxx
044 xxxxxXxxxxxxxxxxxxxx
045 xxxxxxXxxxxxxxxxxxxx
046 xxxxxxxXxxxxxxxxxxxx
047 xxxxxxxxXxxxxxxxxxxx
048 xxxxxxxxxXxxxxxxxxxx
049 xxxxxxxxxxXxxxxxxxxx
050 xxxxxxxxxxxXxxxxxxxx
051 xxxxxxxxxxxxXxxxxxxx
052 xxxxxxxxxxxxxXxxxxxx
053 xxxxxxxxxxxxxxXxxxxx
054 xxxxxxxxxxxxxxxXxxxx
055 xxxxxxxxxxxxxxxxXxxx
056 xxxxxxxxxxxxxxxxxXxx
057 xxxxxxxxxxxxxxxxxxXx
058 xxxxxxxxxxxxxxxxxxxX
059 xxxxxxxxxxxxxxxxxxXx
060 xxxxxxxxxxxxxxxxxXxx
061 xxxxxxxxxxxxxxxxXxxx
062 xxxxxxxxxxxxxxxXxxxx
063 xxxxxxxxxxxxxxXxxxxx
064 xxxxxxxxxxxxxXxxxxxx
065 xxxxxxxxxxxxXxxxxxxx
066 xxxxxxxxxxxXxxxxxxxx
067 xxxxxxxxxxXxxxxxxxxx
068 xxxxxxxxxXxxxxxxxxxx
069 xxxxxxxxXxxxxxxxxxxx
070 xxxxxxxXxxxxxxxxxxxx
071 xxxxxxXxxxxxxxxxxxxx
072 xxxxxXxxxxxxxxxxxxxx
073 xxxxXxxxxxxxxxxxxxxx
074 xxxXxxxxxxxxxxxxxxxx
075 xxXxxxxxxxxxxxxxxxxx
076 xXxxxxxxxxxxxxxxxxxx
077 Xxxxxxxxxxxxxxxxxxxx
078 xXxxxxxxxxxxxxxxxxxx
079 xxXxxxxxxxxxxxxxxxxx
080 xxxXxxxxxxxxxxxxxxxx
081 xxxxXxxxxxxxxxxxxxxx
082 xxxxxXxxxxxxxxxxxxxx
083 xxxxxxXxxxxxxxxxxxxx
084 xxxxxxxXxxxxxxxxxxxx
085 xxxxxxxxXxxxxxxxxxxx
086 xxxxxxxxxXxxxxxxxxxx
087 xxxxxxxxxxXxxxxxxxxx
088 xxxxxxxxxxxXxxxxxxxx
089 xxxxxxxxxxxxXxxxxxxx
090 xxxxxxxxxxxxxXxxxxxx
091 xxxxxxxxxxxxxxXxxxxx
092 xxxxxxxxxxxxxxxXxxxx
093 xxxxxxxxxxxxxxxxXxxx
094 xxxxxxxxxxxxxxxxxXxx
095 xxxxxxxxxxxxxxxxxxXx
096 xxxxxxxxxxxxxxxxxxxX
097 xxxxxxxxxxxxxxxxxxXx
098 xxxxxxxxxxxxxxxxxXxx
099 xxxxxxxxxxxxxxxxXxxx
100 xxxxxxxxxxxxxxxXxxxx
[download]