Yow! That code is almost obfuscated! At the very least, if you are teaching people perl, please always check the return value of 'open'! Here is my rewrite, trying to maintain some of the spirit of the original: 
#!perl

use strict;

my(@santa);
my($total,$x,$y,$found,$old);
my(%gift);
my($name, $name2, $email, $email2);

while(<>) {
  chomp;
  m/::/ && push(@santa, $_);
}

my $mail     = "/usr/lib/sendmail -t -oi -odq";
my $mailfrom = "kris.kringle\@north.pole";
my $subject  = "Your Kris Kringle Recipient";

## Give everyone a present from a random person:
$total=0; srand;
for $y (@santa) {
  $found=0;
  $total++;
  while (!$found) {
    $x = $santa[rand @santa];
    $y eq $x && next; ## No presents to self!
    

    ## What if the only person left is yourself? This solves that:
    if ($total == @santa && !$gift{$y}) { 
      ## Switch with another!
      $old = $gift{$x};
      $gift{$x}=$y;
      $gift{$y}=$old;
      last;
    }

    $gift{$x} && next; ## No more than one present per person
    $gift{$x}=$y; $found++;
  }
}

## Now we send out the email:
for $y (@santa) {
  ($name, $email)   = split(/::/, $y);
  ($name2, $email2) = split(/::/, $gift{$y});

  open(MAIL, "|$mail $email") || die "Could not open $mail: $!\n";
  print MAIL <<"NORTHPOLE";
From: $mailfrom
To: "$name" <$email>
Subject: $subject

$subject is: $name2 ($email2)

K.K.

Please do NOT reply! 'I' am a program:
NORTHPOLE

  open(SELF, $0) || die "Could not open $0: $!\n";
  while(<SELF>) { print MAIL; }
  close(SELF) || die "Could not close $0: $!\n";
  close(MAIL) || die "Could not close $0: $!\n";
}
exit;

[download]
The little section that begins "if ($total == @santa...)" is there to prevent the following condition. Say we have three people, A, B. and C. A randomly gets assigned to B, then B gets assigned to A. At this point, the only person C can give a present to who has not gotten one is herself, which is not allowed! Hence, the little snippet above, which neatly solves that. Enjoy!

In reply to RE: Kris Kringle Script by turnstep
in thread Kris Kringle Script by Marburg

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.