表单提交后PHP标头重定向不起作用

Question

I have a snippet of code that posts information the user enters into a form, to the DB. After the last line of PHP that submits the data to the DB I have:

header("location:http://www.site.com/page.htm");

This doesn't seem to do anything. It still posts all the user info to the DB, but the page clears out and thats it. No redirect.

Here is the whole snippet:

<?php
if(isset($_POST['register'])){
    $username = ($_POST['username']);
    $password = ($_POST['password']);
    $email = ($_POST['email']);
    $email2 = ($_POST['email2']);
    $password2 = ($_POST['password2']);
    $commname = ($_POST['commname']);
    $outpostname = ($_POST['outpost']);
    $special = ($_POST['specialty']);

    if($username == "" || $password == "" || $email == "" || $password2 == "" || $email2 == "" || $commname == "" || $outpostname == "" || $special == "no"){
        echo "Please supply all required fields!";
    }elseif(strlen($username) > 20){
        echo "Username must be less than 20 characters!";
    }elseif(strlen($email) > 100){
        echo "E-mail must be less than 100 characters!";
    }elseif(strlen($email2) > 100){
        echo "E-mail verify must be less than 100 characters!";
    }elseif(strlen($commname) > 20){
        echo "Your Commander's name must be less than 20 characters!";
    }elseif(strlen($outpostname) > 20){
        echo "Your Outpost's name must be less than 20 characters!";
    }else{
        $register1 = mysqli_query($myConnection,"SELECT `id` FROM `user` WHERE `username`='$username'") or die(mysqli_error($myConnection));
        $register2 = mysqli_query($myConnection,"SELECT `id` FROM `user` WHERE `email`='$email'") or die(mysqli_error($myConnection));
        if(mysqli_num_rows($register1) > 0){
            echo "That username is already in use!";
        }elseif(mysqli_num_rows($register2) > 0){
            echo "That e-mail address is already in use!";
        }else{
            $spec = ($_POST['specialty']);
            $comnam = ($_POST['commname']);
            $postnam = ($_POST['outpost']);                                                    
            $rand_col = rand(1,5); /*Number of Colonies that exist in the game*/
            $ins1 = mysqli_query($myConnection,"INSERT INTO `stats` (`username`,`credits`,`food`,`land`,`energy`,`turns`,`turns_max`,`gas`,`ore`,`population`,`buildeff`,`offpts`,`defpts`,`score`,`specialty`) VALUES ('$username',2000,2000,100,2000,30,30,2000,2000,500,100,0,0,0,'$spec')") or die(mysqli_error($myConnection));
            $ins2 = mysqli_query($myConnection,"INSERT INTO `unit` (`username`,`trainee`,`juggernaut`,`infantry`,`marauder`,`terminator`,`reconsq`,`prisoner`,`destroyer`,`colossus`) VALUES ('$username',100,0,50,0,0,0,0,0,0)") or die(mysqli_error($myConnection));
            $ins3 = mysqli_query($myConnection,"INSERT INTO `user` (`colonynum`,`username`,`password`,`email`,`specialty`,`commname`,`outpostname`) VALUES ('$rand_col','$username','".md5($password)."','$email','$spec','$comnam','$postnam')") or die(mysqli_error($myConnection));
            $ins4 = mysqli_query($myConnection,"INSERT INTO `structure` (`username`,`agridome`,`spaceport`,`barrack`,`researchfac`,`laserbat`,`factory`,`infirmary`,`trainingfac`) VALUES ('$username',1,0,5,0,0,0,1,1)") or die(mysqli_error($myConnection));
            header("location:http://www.site.com/page.php");
        }
    }
}
?>

and yes I know, I should be using some SQL injection protection but cant get that working just yet.. that will come later ;)

Answer 1

Change

header("location:http://www.site.com/page.php");

to

header("location: http://www.site.com/page.php");

Also, if u even have one character outputed before the header command (ie body of the http request) it will fail. Turn on PHP error reporting to see if this is the case.

Output characters can even be white chars, something between the <?php and the beginning of the page.

Like: ======page starts below this line=======

   <?php  

Notice there are white characters before the <?php

Answer 2

If your header isn't working, it is because your script produced an output (eg an error message, because of unchecked GET parameters), before the header is sent. Check your webserver's error log, which should contain the information, what exactly fails.

Answer 3

All headers need to be sent to the browser before any other type of output (error messages, HTML, Javascript, etc).

In your case, you have a lot going on in the script before you call header() , and one or more of those lines of code are generating output. Once that happens, you can no longer send header information.

To fix the problem, determine what is generating output and remove it, or move the header() call nearer to the top of the script before any echo statements, mysqli* statements, or any other line that can produce output.

Answer 4

Got it to work using:

$url = '/page.php';
echo '<META HTTP-EQUIV=Refresh CONTENT="0; URL='.$url.'">';