#!/usr/bin/perl

use strict;
use CGI;

 my $page  = new CGI;

 if( $ENV{ 'REQUEST_METHOD' } eq 'GET' ){

    my $data = <<json;
    {
    "isbn" : "123456",
    "title" : "Programming Perl",
    "author" : "L. Wall"
     }
json

     print $page->header('application/json');

     print $data;
 }