PHP. include, require. Reserved variables

PHP. include, require. Reserved variables

https://www.w3schools.com/php/php_includes.asp

Reserved variables:
$_GET
$_POST
$_SERVER
$_SERVER['PHP_SELF']
$_SERVER['PATH']
$_ENV
$_SESSION
$_COOKIES

https://www.php.net/manual/en/reserved.variables.php

https://www.w3schools.com/php/php_superglobals.asp

https://www.w3schools.com/php/php_superglobals_get.asp

https://www.w3schools.com/php/php_forms.asp

1. Example, how to use forms:

<form method="post" action="test_get.php">
<input type="text" name="fname" value = "<?php echo @$_POST['fname']; ?>">
<input type="submit">
</form>

<?php

echo "We have confirmed your name: <b>" . @$_POST['fname'] . "</b>";

?>

1a. Example about useage of GET. This is UNSECURE example, because GET method is used instead of POST for password and user. The reason is to test and see variables for learning purposes:

Not flexible code
<a href = "noPage.php?name=xyz&surname=sss">Ok</a><br />
More flexible code
<a href = "<?php echo $_SERVER['PHP_SELF']; ?>?name=xyz&surname=sss">Ok</a><br />
<?php

?><hr />GET vars <br /><?php

foreach ( $_GET as $r=>$b){
echo "$r = $b <br />";
}

?><hr />SERVER vars<br /><?php

foreach ( $_SERVER as $r=>$b){
echo " $r = $b <br />";
}

?><hr />Array var<br><?php

echo "{$_SERVER["QUERY_STRING"]} <br />";

?>

2. Prototype of registration:

<h3>MAIN</h3>
<a href= "<?php echo $_SERVER['PHP_SELF']; ?>">Home</a><br />
<?php

$passwd = @$_GET["passwd"];
$user = @$_GET["user"];

if ( ! $user or ! $passwd ){

    ?>

    <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="get">

    <input type="text" name="user" value=""><br />

    <input type="password" name="passwd" value=""><br />

    <input type="submit" name = "OK"><br />

    </form>

    <?php

} elseif ($user == "jonas" && $passwd=="1972"){

    include("my.html");

} elseif ($user=="petras" && $passwd=="1973"){

    include("other.html");

}else{

    echo "not good <br />";

}

?>

my.html:

my blah blah

other.html:

other blah blah

Task 1:
1. Please create 3rd user "john" and his data page
2. Please create control code box (e.g. voucher code), which can be used by the users. It is
123. User can not see data without the code. Form view:

user: [ ]
password: [ ]
control: [ ]

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PHP. include, require. Reserved variables

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