CSci 4608 Principles of Web Programming: Examples of Perl programs and scripts

1. Write your script using a plain-text editor, such as emacs or pico (or vi if you want to feel like a real Perl hacker).
2. Make sure your file has an extension .cgi, set the file permissions to rwxr-xr-x:
   chmod a+rx myscript.cgi
3. Make sure that the form action is set to the absolute URL of the script.
4. You may test it by typing perl myscript.cgi at the command prompt.
5. If you are running into problems, check out the StudentDiscussion Wiki page, it may have an answer to your question, or you might want to post the question there.

• Example 1. Here is the form that tests this example. Below is the cgi script file used in the example:

  
  #!/usr/bin/perl
  
  use CGI param,header,p,b,start_html,end_html;
  
  $name = param("your name");
  $food = param("food");
  print header();
  print start_html();
  print p("Hi $name!");
  print p();
  print b("Would you like some $food?");
  print end_html();
  

  You can also handle the same form using POST method
• A bit more advanced version of the same example. Click here for the form (includes the form validation, needs to be changed so that it works in IE).. The script for that example (slightly different from the one above) is here:

  
  #!/usr/bin/perl -w
  
  use CGI param,header,p,b,start_html,end_html;
  
  $name = param("yourname");
  $food = param("food");
  $broccoli = param("broccoli");
  print header();
  print start_html();
  print p("Hi $name!");
  print p();
  print b("Would you like some $food?");
  if ($broccoli eq "cantstandit") {
      print p("No broccoli for you");
  }
  elsif ($broccoli eq "notcrazy") {
      print p("Have a bit of broccoli first");
  }
  else {
      print p("Here is a huge plate of broccoli for you!");
  }
  #print p("$broccoli");
  print end_html();
  

• This perl program creates a small database with one entry indexed by the key 'key1' the first time it runs (it creates two files mydbm.dir and mydbm.pag). On subsequent runs the program updates the database.

   
  #!/usr/bin/perl -w
  
  dbmopen (%data, "mydbm", 0666) || die "can not open the database file";
  
  $data{'key1'} = $data{'key1'} + 1;
  print "$data{'key1'}\n";