Show them Perl's greatest asset -- concise solutions to everyday problems.

If you have time, pick some task that will resonate with as many of them as possible and get one or more of them to solve the chosen task in their favoured langugages before the day.

By way of example (because the examples already exist): frequency count the words in a text file.

• C (211 lines):
  <Reveal this spoiler or all spoilers in this node or all in this thread>
• C++ (79 lines):
  <Reveal this spoiler>
• Java (68 lines):
  <Reveal this spoiler>
• Python (24 lines):

  #!/usr/local/bin/python
  # $Id: wordfreq.python,v 1.9 2001/05/11 17:44:00 doug Exp $
  # http://www.bagley.org/~doug/shootout/
  #
  # adapted from Bill Lear's original python word frequency counter
  #
  # Joel Rosdahl suggested using translate table to speed up
  # word splitting.  That change alone sped this program up by
  # at least a factor of 3.
  #
  # with further speedups from Mark Baker
  
  import sys
  
  def main():
      count = {}
      i_r = map(chr, range(256))
  
      trans = [' '] * 256
      o_a, o_z = ord('a'), (ord('z')+1)
      trans[ord('A'):(ord('Z')+1)] = i_r[o_a:o_z]
      trans[o_a:o_z] = i_r[o_a:o_z]
      trans = ''.join(trans)
  
      rl = sys.stdin.readlines
  
      lines = rl(4095)
      while lines:
          for line in lines:
              for word in line.translate(trans).split():
                  try:
                      count[word] += 1
                  except KeyError:
                      count[word] = 1
          lines = rl(4095)
  
      l = zip(count.values(), count.keys())
      l.sort()
      l.reverse()
  
      print '\n'.join(["%7s\t%s" % (count, word) for (count, word) in l]
  +)
  
  main()
  [download]

• Haskell (20 lines):
  <Reveal this spoiler>

And then write & run your perl solution in real time:

perl -nle"y/a-zA-Z/ /cs; ++$h{$_} for split }{ print qq[$_:$h{$_}] for
+ sort keys %h" theFile
break:1
brief:1
bring:3
brought:2
buffalo:16
burden:1
but:20
by:16
call:2
called:6
came:2
campaign:1
can:36
cannot:2
capable:1
capitals:1
career:2
cart:1
case:2
...
[download]