php form submitting empty variables

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Views: 459 | Replies: 4 | Solved

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Join Date: Dec 2006

Location: Damascus - Syria

Posts: 8

Reputation: rori is an unknown quantity at this point

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Solved Threads: 0

rori

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Newbie Poster

php form submitting empty variables

May 8th, 2008

hi,
i have this code to submit a login form:

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<?php
if(!isset($aid)){
?>
you must login:<br>
<form name="form1" method="post" action="<?=$PHP_SELF?>">
  <input type="text" name="aid"><br>
  <input type="password" name="apass><br>
  <input type="submit" name="submit" value=" Login "><br>
</form>
<?php
}
else{
?>
welcome etc...
<?php
}
?>

this code was working fine until something changed on the host server and i think it was register_globals changed from on to off and after that $aid is always empty except if i specifically call it as $_POST['aid'].
my question is: is my code above considered a good code, or should i use the $_POST and assign the value to the $aid variable instead of just using $aid directly? because i have many pages that i have to change this in.
i hope my question is clear... and thank you for your time.

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Join Date: Oct 2006

Posts: 26

Reputation: Rayhan Muktader is an unknown quantity at this point

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Solved Threads: 2

Rayhan Muktader Rayhan Muktader is offline

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Re: php form submitting empty variables

May 8th, 2008

You must refer to the user inputs as $_POST[aid] and $_POST[apass]. DO NOT refer to them as $aid and $apass (don't even save them as variables if possible). There are many situation where this will come back to bite you in the rear if you do. I will mention the most detrimental one which is called called sql injection. Lets assume that you are saving user data in a sql database and your form page is called rori.com. What do you think you might happen if I typed in something like rori.com?aid=drop+database in the address bar? Your code might pass $aid to the database where it will get executed. You should run some checks on $_POST[aid] and put it into something that does not resemble the variable name $aid then insert it in the database. Just google sql injection if you want a more elaborate explanation.
PS. You should thank whomever turned off global_register on the server so you can't refer to $_POST[aid] as $aid anymore. Then yell at him for ever having it turned on.

Last edited by Rayhan Muktader : May 8th, 2008 at 3:06 pm.

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Join Date: Feb 2008

Location: Ottawa, Ontario

Posts: 15

Reputation: mom_of_3 is an unknown quantity at this point

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mom_of_3

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Newbie Poster

Re: php form submitting empty variables

May 8th, 2008

If the register globals are set to off then you are going to have to use $_POST.

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<?php
if(!isset($_POST['aid'])){
?>
you must login:<br>
<form name="form1" method="post" action="<? $_SERVER['PHP_SELF']; ?>">
  <input type="text" name="aid"><br>
  <input type="password" name="apass><br>
  <input type="submit" name="submit" value=" Login "><br>
</form>
<?php
}
else{
?>
welcome etc...
<?php
}
?>

Last edited by mom_of_3 : May 8th, 2008 at 3:09 pm.