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):

  // $Id: wordfreq.java,v 1.3 2000/12/17 21:40:53 doug Exp $
  // http://www.bagley.org/~doug/shootout/
  // Collection class code is from my friend Phil Chu, Thanks Phil!
  
  import java.io.*;
  import java.util.*;
  import java.text.*;
  
  class Counter {
      int count = 1; 
  }
  
  public class wordfreq {
  
      public static void main(String[] args) {
      wf();
      }
  
      public static String padleft(String s,int n,char c) {
          int len = s.length();
          if( len>=n ) return s;
          char[] buf = new char[n];
          for( int i=0;i<n-len;i++ ) buf[i]=c;
          s.getChars(0,len,buf,n-len);
          return new String(buf);
      }
    
      public static void wf() {
          HashMap map = new HashMap();
          try {
              Reader r = new BufferedReader(new InputStreamReader(System
  +.in));
              StreamTokenizer st = new StreamTokenizer(r);
              st.lowerCaseMode(true);
              st.whitespaceChars( 0, 64 );
              st.wordChars(65, 90);
              st.whitespaceChars( 91, 96 );
              st.wordChars(97, 122);
              st.whitespaceChars( 123, 255 );
              int tt = st.nextToken();
              while (tt != StreamTokenizer.TT_EOF) {
                  if (tt == StreamTokenizer.TT_WORD) {
                      if (map.containsKey(st.sval)) {
                          ((Counter)map.get(st.sval)).count++;
                      } else {
                          map.put(st.sval, new Counter());
                      }
                  }
                  tt = st.nextToken();
              }
          } catch (IOException e) {
              System.err.println(e);
              return;
          }
  
          Collection entries = map.entrySet();
      // flatten the entries set into a vector for sorting
      Vector rev_wf = new Vector(entries); 
  
          // Sort the vector according to its value
          Collections.sort(rev_wf, new Comparator() {
          public int compare(Object o1, Object o2) {
              // First sort by frequency
              int c = ((Counter)((Map.Entry)o2).getValue()).count - ((Co
  +unter)((Map.Entry)o1).getValue()).count;
              if (c == 0) { // Second sort by lexicographical order
              c = ((String)((Map.Entry)o2).getKey()).compareTo((String)(
  +(Map.Entry)o1).getKey());
              }
              return c;
          }
          }
               );
  
          Iterator it = rev_wf.iterator();
      Map.Entry ent;
      String word;
      int count;
          while(it.hasNext()) {
              ent = (Map.Entry)it.next();
          word = ((String)ent.getKey());
          count = ((Counter)ent.getValue()).count;
          System.out.println(padleft(Integer.toString(count),7,' ') + "\
  +t" + word);
          }
      }
  }
  [download]

• Python (24 lines):
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• Haskell (20 lines):
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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]