my php codes

what do we do to display the common file name that php file shares

<?php
//echo 'hello';
echo $_SERVER['SCRIPT_NAME'];// WILL TAKE THE SCRIPT NAME AND DISPLAY IT
//echo $var;
?>

vid lec - 61

first file 1.php
<?php

include 'inc.php';

if(isset($_POST['submit'])){
echo 'process 1';

}

?>

file 2.php

<?php

include 'inc.php';

if(isset($_POST['submit'])){
echo 'process 2';

}

?>

inc.php

<?php

$script_name= $_SERVER['SCRIPT_NAME'];// WILL TAKE THE SCRIPT NAME AND DISPLAY IT
echo $script_name;
?>

<form action="<?php echo $script_name; ?>"  method="POST">
<input type="submit" name="submit" value="Submit">
</form>
//

will display the name of page we are in inspite of the fact that the running code of that part was included but that became independent bcz of the use of server[script_name];



to see your ip address

<?php

$ip_address= $_SERVER['REMOTE_ADDR'];
echo $ip_address;

// this isnt always a good way to get users ip address, esp when they are on a shared network
// or someone may be using proxy
?>

so what we can do is that we cant check wherether he using a proxy, or is in a shared network
there are ready made functions discussed in video lec

to print an array we use print_r();

to check whether the form has been left empty in the type POST  or get,
we use function (!empty(nameofvariable))

isset()-> just checks whether the submit button has been clicked or not

when we start a session , we create a file on the server side , and that file after its created should be accessible to every page.

SIMPLE CODE FOR SETTING UP SESSION
<?php
session_start();
$_SESSION['name']="alex";
//echo $_SESSION['name'];
?>

CODE TO VIEW SESSION

<?php

session_start();
echo $_SESSION['name'];

?>

a better way to log in , and to check whether user has his session or not and ask him to log in

<?php

session_start();
if(isset($_SESSION['name'])){
echo $_SESSION['name'];
}
else
{
echo 'plz log in.. ';
}
?>

TO END SESSION

<?php
// unset a session

session_start();  // though we are unsetting a session we do need to start the session

unset($_SESSION['name']);
?>

COOKIES

setcookie('username','value',time);// time in seconds

the time here is in terms of timestamp so we save the time stamp
$time= time(); // this time() returns timestamp
and in the parameter we write $time+5 , that sets the cookie for 5 secs

now if one wants to log out , can again set the cookie with time-> $time -5

sql database connection

now, when we connect to database , if there is an improper connection it might show an error,
 to avoid that display of error we write thr statement like

<?php
$mysql_host = 'localhost';
$mysql_user='alex';
$mysql_pass='';

mysql_connect($mysql_host, $mysql_user, $mysql_pass );

// instead of writing the above statement  (which can display the error mesg)we can write

mysql_connect($mysql_host, $mysql_user, $mysql_pass ) or die('could not connect');

>?

we can write the above code in a file and include wherever needed

after connecting to the dbms we need to specify the dbms we need to connect to

my_sql_dbms(nameofDbms);

for any query we need to write it as a string and save that in a variable and then pass that in the function
mysql_query();