session handling in php

Anon

hai friends,
can anyone help me in session handling
i wanna maintain session for each user
actually i have gone thro many documentations and examples but iam unable to implement in my work
so what should i do?
iam totally new to use session handling functions
so where exactly i have to add them ,how?
regards
roopa

fahad

Session handling in PHP is very easy. What you need to do is to call the function session_start() on the top of every php page on which you want to access session variables. Then use the session_register(String) method to register variables in the session. The only YOU MUST REMEMBER is that, session_start() is the FIRST LINE of your PHP page. Nothing (which results output is allowed,as HTTP headers must be sent before actual out put).  So make it first statement of your every script,which contributs to session. Example

HOW TO REGISTER A VARIABLE
----------- 1.php -----------
<?// First line, no space

session_start(); // First statement

$name = "fahad";

session_register("name");

// Note that variable name is in form of string
?>

<a href="2.php">Click here</a>

HOW TO RETRIEVE A VARIABLE
----------- 2.php -----------
<?// First line, no space

session_start(); // First statement

// Now name is available 🙂

echo $name; // Will show fahad🙂

for more, see
a cool article
http://www.phpbuilder.com/columns/mattias20000105.php3
(Mattias Nilsson is a cool guy 🙂)

for Docs about PHP sessions, see

http://www.php.net/manual/en/ref.session.php

Best Wishes
fahad

kikidonc

Thank you very much!!!
I was looking for that all the day:-)

Fred.

Anon

hello fahad,
Thanks for the quick reply
Actually i got the idea about session handling
when i tried to do so i found that the session id being stored in /tmp i know that In php.ini file this is the path but do i have to make any changes in php.ini esp for session handling
what my requirement is once a user is logged in and when he logs off the next user whoever logs in should not be able to access the pages accessed by the first user by just clicking the browser's back button
This includes a lot of session handling functions i knowcan u give me a entire example where this is done
it will be agreat help
Regards
Roopa

kikidonc

And, what is the real syntax to delete a variable and its value in a session???

Here is what I've done:

session_start();
$myVar = "value";
session_register("myVar");

To delete the registration of this variable; I tried:
session_start(); //first line in one of my pages
session_unregister("myVar");

But if I do right after
echo $myVar;
it's still there and Value is printed.

Plus (one more piece of info needed)
If I were in an other page and did:
session_start();
and right after
$myVar = "newValue";
Would this new value be uploaded? If I were in a new page and I did session_start();, would the value of $myVar be "Value" or "newValue"???

Thank you very much for that,
Greetings,
Fred.

fahad

the thing for which you are looking is quite easy! here is an example, enjoy!

---------------- Index.php

.........
.......
.........

<input type="submit">

</form>

.........
..........

------------------ login.php

session_start();

// Check that login name and passwords are ok or not, if ok, do following

session_register("loginName");

header("location:welcome.php");

------------------ welcome.php
<?

session_start();

// No check that whether session loginName is registered or not. If it is not, it means that
// User is not logged in and heance throw him to login page!

if(!session_is_registered("loginName"))
	header("location:index.php");

// NOW IF REGISTERED USER CLOSES THE BROWSER OR LOGS OFF, HIS SESSION VAR IS ALSO
// DESTROYED HENCE IF SOMEONE TRIES TO ENTER HIS PAGE, HE WON'T BE ABLE TO DO SO!

// TO DESTROY THE VAR, USER MUST CLOSE THE BROWSERS (like yahoo! asks)  OR SHOULD CLICK
// THE LOG OFF LINK AS GIVE BELOW.

<head>
<title> New Document </title>
</head>

</body>

------------------- logOff.php
<?

session_start();

// Simply reset the session or destroy it!

session_unset();

// or use session_destroy();

header("location:index.php");

Isn't it easy??????



Best  Wishes
fahad

fahad

Answer to your first question is, after unregistering the session, ie call to session_unregister(), variable is
unregistered but is still available at ONLY that page. Try to access it on another page 🙂 Also, if you chane the
contents of the variable, after registering it, registered value is also changed.

Hope following examples would clear your concepts.....

copy them and try to run them on your server.....



Best Wishes............
Fahad

------------------------------ INDEX.php ------------------------
<?

// index.php

session_start();

$name = "me";

session_register("name");

$name = "you";

<head>
<title> New Document </title>
</head>

echo $name;	// Out put will be you, got it why?

<br>
<a href="2.php">click here</a>

</body>

------------------------------ 2.php ------------------------
<?

// 2.php

session_start();

<head>
<title> New Document </title>
</head>

echo $name;	// Out put will be you, as variable was over written....

<br>
<a href="3.php">click here</a>

</body>

------------------------------ 3.php ------------------------
<?

// 3.php

session_start();
session_unregister("name");

<head>
<title> New Document </title>
</head>

echo $name;	// is here but will not be on next page.........

<br>
<a href="4.php">click here</a>

</body>

------------------------------ 4.php ------------------------
<?

// 3.php

session_start();

// NAME is not here!

<head>
<title> New Document </title>
</head>

if(session_is_registered("name"))
	echo ("NAME IS HERE");
else
	echo ("NAME IS NOT HERE");

</body>