电子邮件中的验证链接

Question

Been trying this for ages :(

Upon registering, each user gets a randomly generated number which is stored in a table called "hash".

After much turmoil I have set up phpmailer and got the whole email process working, all fine, no worries.

BUT I have encountered a problem and I have even read answers on this site that haven't helped. I simply want to create a unique activation link depending on the hash. So for example:

User with "hash" as "12345" gets their verification email, I want the hyperlink to look like this - www.example.com/verify.php?hash=12345

And the same for each other user, here's how I'm currently trying it

<?php
$link_address = "verify.php?hash='.$hash.'";
echo "<a href='$link_address'> Activate </a>";   
?>

This displays "Activate "; ?>"

Very weird :(

EDIT

This is the guide I've previously tried to copy from - http://code.tutsplus.com/tutorials/how-to-implement-email-verification-for-new-members--net-3824

It is outdated and the default mail() function doesn't work for what I want, I'm particularly up to Step 5

EDIT 2

Mail body generation code

$body             = file_get_contents('C:\wamp\www\Game\examples\contents.html');

BIG EDIT!!

New code:

<?php


include("connect.php");

$username = $_POST['username'];


$id_get = mysqli_query($con,"SELECT units.id, users.id, users.username FROM units, users WHERE     users.username = '$username' AND units.id = users.id");
$gotid = mysqli_fetch_array($id_get);
$id4 = $gotid["id"];

$stuff_get = mysqli_query($con,"SELECT users.id, users.email, users.hash, users.username FROM users     WHERE users.username = '$username' AND users.id=$id4");
$gotstuff = mysqli_fetch_array($stuff_get);
$hash2 = $gotstuff['hash'];
$email2 = $gotstuff['email'];
$username2 = $gotstuff['username'];
echo "Your username is ",$username2,"<br>";
echo "Your activation code is ",$hash2,"<br>";

?>

From there I'm trying to get the submitted username (from the registration) and get information from the database (IDs, emails etc) then simply display the username and the hash in the email.

Usually this would be super easy but I'm getting the good old "Notice: Undefined index: username"!!

EDIT

For a completely simple run down on the situation.

I want to be able to get one variable from a page to another page for example.

page1.php

Has a variable called "$users"

page2.php

Wants to echo $users

But I do not know how to make the variable $users specifically from page1.php available on page2.php!

Answer 1

"verify.php?hash='.$hash.'"; 

Isn't Correct, you don't need the apostrophy and the dot to include the variable in a double quoted string. try

"verify.php?hash=$hash";

then do something like this mail($email, 'Please activate your account', "Hello " . $username. ", Thank you for registering with us. Please visit the link below so we can activate your account: http://www.example.com/verify.php?hash=" . $hash . " -- Example team");

Then on you verify page use

S_GET['hash'] 

and check if it's correct against a database. I would also add the email in the url so you can check the email and code against each other, just in case you give out the same hash twice.