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					Chapter 9 – Cookies, Sessions, FTP,
          Email and More
         spring into PHP 5
        by Steven Holzner


       Slides were developed by
               Jack Davis
     College of Information Science
            and Technology
           Radford University




                                      1
            PHP Sending Email

• The PHP installation has to include some
  specifications for how to send email, in
  particular the PHP initialization file must
  specify the connections to the email system.

• At RU, this has been done.


• To send email in a PHP script use the mail
  function.

  Mail(string to, string subject, string message,
       [,string additional_headers [,
         string additional_parameters]])

  This sends an email to the email address in to,
  with subject subject and message message.
  You can also set additional mail headers and
  parameters to mail.

  $result = mail(steve@ispname.com, “Web
  mail”, $_REQUEST[“message”]);

  **message is retrieved from html form

                                                    2
      PHP Email w/Headers (mailinput.php)

• Additional email headers like the following
  may be specified.

  cc (“carbon copy”)

  bcc (“blind carbon copy”)

  These are set with the additional_headers
  parameter.

  $headers .= “cc:” . $_REQUEST[“cc”] . “\r\n”;

  $headers .= “bcc:” . $_REQUEST[“bcc”] .
  “\r\n”;

  $result = mail(“steve@chooseanisp.com”,
                 “Web mail”,
                 $_REQUEST[“message”],
                 $headers);

• Can also send email with attachments.


                                                  3
                PHP Cookies

• Cookies hold text that you can store on the
  user’s computer and retrieve later. They are
  set using the setcookie function.

  setcookie parameters:

  name       - cookie name

  value      - value to be stored on the client
               machine

  expire     - time the cookie expires, set with
               PHP time function (1/1/70)

  path      - path on the server on which the
              cookie will be available

  domain    - domain for which the cookie is
              available

  secure    - indicates that the cookie should
              only be transmitted via https.

                                                   4
                PHP Cookies

• Cookies are part of the HTTP headers sent to
  the browser, and so they must be sent before
  any other output from the PHP script. Calls to
  this function must occur before any other
  output from your script. This means calls to
  setcookie must occur before any other output
  including <html> and <head> tags. If some
  output exists before calling this function,
  setcookie may fail and return FALSE.

  <?php
    setcookie(“message”, “No worries.”);
  ?>

  <html>
      …




                                               5
               Getting Cookies

• After a cookie is set, it won't be visible to
  scripts until the next time a page is loaded.
  The cookie is sent from the server machine,
  so it won't be sent from the client to the server
  until the next time a request is sent by the
  client. Cookies are sent in the HTTP headers
  to the server from the client, then only if the
  request is for a page from the same domain
  that the cookie came from.

  After cookies are set, they can be accessed on
  the next page load with $_COOKIE array. Say
  a previous page set a cookie named message.
  Then it will be in the global array $_COOKIE.
  So, in the PHP script we have only to access
  the $_COOKIE array, however, we should
  check to see the cookie exists.

  if (isset($_COOKIE['message']))
      {
         echo $_COOKIE['message'];
       }

                                                  6
              COOKIE Arrays

• Cookie names can also be set as array names
  and will be available to your PHP scripts as
  arrays. For example:

  setcookie("cookie[one]","no");
  setcookie("cookie[two]","worries");
  setcookie("cookie[three]","today.");


  After these cookies have been set, they could
  be read after the next request like this:

  if (isset($_COOKIE['cookie']))
     {
       foreach ($_COOKIE['cookie'] as $data)
           {
              echo "$value <br />";
            }
     }




                                                  7
          Cookie Expiration Time

• You can also specify how long the cookie
  should exist on the user's machine. The
  cookie will be deleted when the user ends the
  current browser session (which usually means
  closing all browser windows). So, normally
  we'll want to specify how long a cookie should
  last by giving a value for the expire parameter.

  Normally, we use the time function which
  returns current time, then add the number of
  seconds we want the cookie to last.

  setcookie("mycookie", $value, time() + 3600);
  How long will this cookie last?

• Delete a Cookie
  just set the cookie's value to "" and call
  setcookie with the same parameters as the
  cookie was set with. When the value
  argument is set to an empty string, and all
  other arguments match a previous call, then
  the cookie will be deleted from the user's
  machine.
                                                  8
                PHP Sessions

• When clients are working with various pages
  in your web application, all the data in the
  various pages is reset to its original values
  when those pages are loaded. That means all
  the data is reinitialized between accesses.
  There are times when you want to retain data
  from a single client longer. To do this you can
  use cookies, hidden fields, or session
  variables.

  Sessions are designed to hold data on the
  server. Each user is given a cookie with his or
  her session ID, which means that PHP will be
  able to reinstate all the data in each user's
  session automatically, even over multiple
  page accesses. If the user has cookies turned
  off, PHP can encode the session ID in the
  URL.




                                                9
            PHP Sessions (cont.)

• Using sessions, you can store and retrieve
  data by name. To work with a session, you
  start by calling session_start. To store data in
  the session, you use the $_SESSION array.

  session_start();
  $_SESSION['color'] = "blue";

  in a separate page you might:
  session_start();
  $color = $_SESSION['color'];

  Session behavior is affected by many settings
  when PHP is installed. For example, session
  variable life is limited to the number of
  minutes specified for session.cache_expire,
  which can only be set during the PHP install.

  All data for a particular session will be stored
  in a file in the directory specified by the
  session.save_path item in the php.ini file. A
  file for each session will be created.

                                                 10

				
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