php functions returns

[chriscloyd]

when you do a return on a function

return false or return true

what happens if its false does it go back to the old page

for example i wanna check if a user name already exist

<?php
$name = $_POST['username'];
function check_username($username) {
$check_username = mysql_query("SELECT * FROM users WHERE username = '$username'");
if ($check_username) {
	$user = mysql_num_rows($check_username);
	if ($user > 0) {
		return false;
	} else {
                        return true;
                }
}
}
?>

how would i check that

say if it returns false i want it to go to a differnet page

 

 

[suzzane2020]

instead of using a return u cud use a header to direct to the page required

 

if($user>0)

{

header("location:filename");

}

[monkey_05_06]

When a function returns it simply means that the function stops executing and the script returns to wherever the function was called from. In your example, you've defined the function, but you're never actually calling it. I assume that this is the action script for an HTML form you're using? The solution is, as suzzane said, to use header to redirect...but you should probably also look into how functions work. You don't seem to completely understand the concept.

[chriscloyd]

no i do lol

now when i do this

<?php
$name = $_POST['username'];
function check_username($username) {
$check_username = mysql_query("SELECT * FROM users WHERE username = '$username'");
if ($check_username) {
	$user = mysql_num_rows($check_username);
	if ($user > 0) {
		return false;
	} else {
                        return true;
                }
}
}
//check username do i do this
if (check_username($name)) {
     //mycode here
} else {
     //header and code here
}
?>

[Guest prozente]

You are passing unchecked user data to mysql. You will want to escape any input from the user otherwise you will have SQL injection on your hand. And if you don't add any protection and you don't have magic quotes on then the user could enter

 

fakename' or '1'='1

 

and it will allow them to login.

 

You need to run the username through mysql_escape_string before you insert it into the query.

 

You could also shorten your if statement by doing the below

 

//check username do i do this
if (!check_username($name)) {
     //header and code here
    exit();
}
//mycode here

 

I hope you are using sessions or cookies on the page you are redirecting the user to if they login correctly.