1. Open Source Server Side Scripting ECA 236 Open Source Server Side Scripting Includes and Dates

2. Open Source Server Side Scripting 2 ECA 236 include( )  include( ) include( ‘ file_name.inc ’ )  PHP includes and evaluates the specified file  if include( ) fails, PHP generates a warning  inherits variable scope of line from which it is called  may contain DTD, HTML, JavaScript, PHP, variables, other includes  may use any extension:.inc.php

3. Open Source Server Side Scripting 3 ECA 236 include( ) cont … header.inc main document Hello,

4. Open Source Server Side Scripting 4 ECA 236 require( )  require( ) require( ‘ file_name.inc ’ )  PHP includes and evaluates the specified file  if require( ) fails, PHP generates a fatal error  inherits variable scope of line from which it is called  may contain DTD, HTML, JavaScript, PHP, variables, other includes  may use any extension:.inc.php

5. Open Source Server Side Scripting 5 ECA 236 include_once( ) include_once( ‘ file_name.inc ’ );  similar behaviors to include( )  if the file has already been included, it will not be included again  use to avoid such problems as:  function redefinitions  variable value reassignment

6. Open Source Server Side Scripting 6 ECA 236 require_once( ) require_once( ‘ file_name.inc ’ );  similar behaviors to require( )  if the file has already been required, it will not be required again  use to avoid such problems as:  function redefinitions  variable value reassignment

7. Open Source Server Side Scripting 7 ECA 236 HTTP Headers  header( ) used to send raw HTTP headers  header( ) MUST be called before anything else is sent to the browser:  HTML  blank spaces or lines  common use for header( ) is to redirect the user to another URI using the Location header

8. Open Source Server Side Scripting 8 ECA 236 HTTP Headers cont …  HTTP requires an absolute URI as an argument to Location <?php header( “Location: http://www.headerExample.com” ); ?>

9. Open Source Server Side Scripting 9 ECA 236 HTTP Headers cont …  You can usually use $_SERVER['HTTP_HOST'], $_SERVER['PHP_SELF'], and dirname( ) to create an absolute URI out of a relative URI. dirname( ) returns path of directory names <?php header( “Location: http://”. $_SERVER[ 'HTTP_HOST‘ ]. dirname( $_SERVER[ 'PHP_SELF‘ ] ). “/”. $relative_url); ?>

10. Open Source Server Side Scripting 10 ECA 236 HTTP Headers cont …  Remember, header( ) must be called before any other output is sent. The following will generate an error:

11. Open Source Server Side Scripting 11 ECA 236 HTTP Headers cont …  headers_sent( ) checks if headers have been sent

12. Open Source Server Side Scripting 12 ECA 236 mail( )  mail( ) takes three required parameters, plus additional optional parameters  to  email address of the recipient  separate multiple addresses with commas  subject  subject line of the email  message  body of the email

13. Open Source Server Side Scripting 13 ECA 236 mail( ) cont …  fourth optional parameter for additional headers such as from, cc, etc $to = “mbarath@neo.rr.com, leland@palmer.com”; $subject = “Test email”; $message = “This is my email message.”; $from = josie@packard.com; mail( $to, $subject, $message, $from );

14. Open Source Server Side Scripting 14 ECA 236 dates and times  date( )  takes two parameters  format string  time stamp (optional) returns current date and time in following format: echo $today = date( “jS F Y” ); 13 th September 2003

15. Open Source Server Side Scripting 15 ECA 236 date( )  examples of format strings  j day of month without leading zeros  S English ordinals  F month, textual, long  Y 4 digit year  for complete list of format strings see the PHP Manual ( php.net )

16. Open Source Server Side Scripting 16 ECA 236 date( ) cont …  string format can contain literals as well as format code  escape letters to print as literals rather than format code echo $today = date( “m/d/Y” ); 9/13/2003 echo $today = date( “jS F in the year Y” ); 13 th September 179 3001e 03epmSat, 13 Sep 2003 13:17:19 -0400 2003

17. Open Source Server Side Scripting 17 ECA 236 date( ) cont …  2 nd parameter is a UNIX time stamp  number of seconds since UNIX Epoch ( midnight 1 Jan 1970 )  32 bit integer 2^ 32  holds up to 2,147,483,647 seconds  will face UNIX “Y2K” in 2038  turned 1 billion on September 08, 2001  if no timestamp is provided, PHP uses current date and time

18. Open Source Server Side Scripting 18 ECA 236 mktime( )  mktime( ) converts a date and time to UNIX time stamp  takes 6 arguments  common programming error is to mix up order of arguments, which differs from UNIX mktime( ) function returns a value of 18001 mktime( hour, minute, second, month, day, year ); mktime( 0, 0, 1, 1, 1, 1970 );

19. Open Source Server Side Scripting 19 ECA 236 mktime( ) cont …  mktime( )  arguments can be left out in order from right to left  leaving out an argument defaults to the timestamp for the current date or time  negative timestamps are not supported under any version of Windows ( limiting the range from 1970 – 2038 ) $timestamp = mktime( ); // returns current date and time

20. Open Source Server Side Scripting 20 ECA 236 mktime( ) cont …  mktime( )  it is possible to use date( ) and mktime( ) together to find dates in the future or past returns the day of the week of the future date, Monday $ts = mktime( 0, 0, 0, 7, 1, 2005 ); echo "July 1, 2005 is on a ". date("l", $ts ) ;

21. Open Source Server Side Scripting 21 ECA 236 getdate( )  getdate( )  takes a time stamp as an optional argument  if no time stamp is provided, getdate( ) returns information on current date and time  returns an associative array with keys and values

22. Open Source Server Side Scripting 22 ECA 236 getdate( ) cont … Key DescriptionExample returned values "seconds" Numeric representation of seconds 0 to 59 "minutes" Numeric representation of minutes 0 to 59 "hours" Numeric representation of hours 0 to 23 "mday" Numeric day of the month 1 to 31 "wday" Numeric day of the week 0 (Sunday) through 6 "mon" Numeric representation of a month 1 through 12 "year" Full numeric representation of yearExamples: 1999 or 2003 "yday" Numeric day of the year 0 through 356 "weekday" Full textual representation day Sunday through Saturday "month" Full textual representation of month January through December 0 Seconds since the Unix EpochSystem Dependent

23. Open Source Server Side Scripting 23 ECA 236 getdate( ) cont … Array( [seconds] => 40 [minutes] => 58 [hours] => 21 [mday] => 17 [wday] => 2 [mon] => 6 [year] => 2003 [yday] => 167 [weekday] => Tuesday [month] => June [0] => 1055901520 ) $today = getdate( ); print_r( $today ); // will print

24. Open Source Server Side Scripting 24 ECA 236 checkdate( )  checkdate( )  checks whether a date is valid  useful for checking user input  takes leap year into consideration  works for date before 1970  takes three integer arguments checkdate( month, day, year ); checkdate( 1, 24, 1956 ); // returns TRUE checkdate( 2, 30, 2003 ); // returns FALSE

25. Open Source Server Side Scripting 25 ECA 236 date and time calculations  one of the easiest ways to compare dates and times is to compare their time stamps  to calculate the difference between two dates, subtract their timestamps