Several complementary functions of session

Several complementary functions of the session are discussed much in PHP. In fact, we have not noticed several functions in PHP4. Let me introduce them to you. Session_set_save_handler () is really a good thing. // ********************* Session_unset (PHP44.0b4) v supplementary functions on the session

In PHP, there are a lot of discussions about Sessions. In fact, there are still several functions in PHP4 that we have not noticed at ordinary times.

Let me introduce them to you.

Session_set_save_handler () is really a good thing.

//********************
Session_unset (PHP4> = 4.0b4)

Void session_unset (void );

This function can leave all session variables registered to null. Note that it is neither unregister nor destroy.

In the following example, this function is well described.


Session_register ("a", "B", "c"); // auto-session-start
$ A = 1;
$ B = 2;
$ C = 3;
Session_unregister ("a"); // unregistrered $
Echo "A: $ a-reg:". session_is_registered ("")."
"; // But the global $ a remains
Session_unset (); // unsets $ B und $ c
Echo "B: $ B-reg:". session_is_registered ("B ")."
"; // The registration remains!
Echo "C: $ c-reg:". session_is_registered ("c ")."
";
Echo session_encode ();
?>

Output:
A: 1-reg:
B:-reg: 1
C:-reg: 1
! B |! C |

//********************************
Session_get_cookie_params (PHP4> = 4.0RC2)

Array session_get_cookie_params (void );

Returns an array that records the cookie information of the current session.
Include:

"Lifetime"-the lifetime of the cookie.

"Path"-cookie storage path.

"Domain"-cookie domain.

//*******************************
Session_set_cookie_params (PHP4> = 4.0b4)

Void session_set_cookie_params (int lifetime [, string path] [, string domain])

This function only applies to the current script file.

//*******************************

The function to be introduced below should be very useful to everyone. are you interested in customizing a session to save without cookies? This function can achieve your assumption.

Let me think about the benefits of using cookies? At least, you don't have to worry about whether the client's cookie function is enabled, right.

Session_set_save_handler (PHP4> = 4.0b4)

Void session_set_save_handler (string open, string close, string read, string write, string destroy, string gc)

This function can define user-level session storage functions (open, close, write, etc ).
For example, this function is useful when we want to save the session in a local database.

!! Note: Before using this function, configure the php. ini file and session. save_hadler = user. otherwise, session_set_save_handler () will not take effect.

In addition, according to my tests, if you want this session to be used across pages, you must add your custom function and session_set_save_handler to each session script file. therefore, the best way is to make a separate file and include it in every session script.

The following example provides a basic session persistence method, similar to the default files method.
If you want to use a database, this is also easy to implement.

Example 1. session_set_save_handler () example


Function open ($ save_path, $ session_name ){
Global $ sess_save_path, $ sess_session_name;

$ Sess_save_path = $ save_path;
$ Sess_session_name = $ session_name;
Return (true );
}

Function close (){
Return (true );
}

Function read ($ id ){
Global $ sess_save_path, $ sess_session_name;

$ Sess_file = "$ sess_save_path/sess _ $ id ";
If ($ fp = @ fopen ($ sess_file, "r ")){
$ Sess_data = fread ($ fp, filesize ($ sess_file ));
Return ($ sess_data );
} Else {
Return ("");
}

}

Function write ($ id, $ sess_data ){
Global $ sess_save_path, $ sess_session_name;

$ Sess_file = "$ sess_save_path/sess _ $ id ";
If ($ fp = @ fopen ($ sess_file, "w ")){
Return (fwrite ($ fp, $ sess_data ));
} Else {
Return (false );
}

}

Function destroy ($ id ){
Global $ sess_save_path, $ sess_session_name;

$ Sess_file = "$ sess_save_path/sess _ $ id ";
Return (@ unlink ($ sess_file ));
}