getting warning "Header may not contain more than a single header, new line detected"

Question

I am doing coding in oops for uploading image in PHP. But After submit image, it's giving warning

"Header may not contain more than a single header, new line detected"

Below is my function, on which its giving error

public function ft_redirect($query = '') {

    if (REQUEST_URI) {

        $_SERVER['REQUEST_URI'] = REQUEST_URI;

    }

    $protocol = 'http://';

    if (HTTPS) {

        $protocol = 'https://';
    }

    if (isset($_SERVER['REQUEST_URI'])) {

        if (stristr($_SERVER["REQUEST_URI"], "?")) {

            $requesturi = substr($_SERVER["REQUEST_URI"], 0, strpos($_SERVER["REQUEST_URI"], "?"));

            $location = "Location: {$protocol}{$_SERVER["HTTP_HOST"]}{$requesturi}";
        } else {


            $requesturi = $_SERVER["REQUEST_URI"];

            $location = "Location: {$protocol}{$_SERVER["HTTP_HOST"]}{$requesturi}";

        }

    } else {

        $location = "Location: {$protocol}{$_SERVER["HTTP_HOST"]}{$_SERVER['PHP_SELF']}";

    }

    if (!empty($query)) {

        $location .= "?{$query}";

    }

    header($location);

    exit;

}

Branham

echo out the values being passed to header() and make sure they don't contain new line characters somehow – Warrenne

echo out value is------> "Location : localhost/filethin/index.php?dir=" But it doesn't contain any new line – Branham

I was having the same problem and it turned out to be an unset variable on the POST request method. – Lesialesion

authenticate method should return a string not a redirect. – Oldster

Answer 1

You shouldn't put more than two lines in URL address. Check you URL.

Good URL - "http://mail.google.com"  - 1 line

Bad URL - "http://mail.              - 2 lines
            google.com/"

Geranium

I've had this error a couple of time recently and every time it's down to a typo missing out closing quotes etc – Horology

It will also happen when you set the header() with the \n(new line characters) in between. – Finback

Answer 2

in "Illuminate\Auth\Middleware\Authenticate" The method "redirectTo" should return an url path, not the Redirect response.

...
protected function redirectTo()
{
    if(\Auth::user()->hasRole('copy')){
        return '/copy/dashboardCopy';
    }       
}
...

Chantilly

You are a savior – Anthracosilicosis

ive been scracthing my head over this. thank you! [+1] – Italia

Answer 3

This warning occurs to indicate that you might have a new line [/n] in the string content of your variables. Example

  header("Location: ../control.php?post='$title1'&sample='$val'");

here there are 2 variables

$title1 and & $val

so while running if This warning occurs warning

“Header may not contain more than a single header, new line detected”

The solution is To strip out the passable new line contents of the variable Like this

    $val=str_replace(PHP_EOL, '', $val);
    $title1=str_replace(PHP_EOL, '', $title1);

Then you can include the variables in the header

---

The ideal way of solving it is like this

$url="../control.php?post='$title1'&sample='$val'";
 $url=str_replace(PHP_EOL, '', $url);
 header("Location: $url");

** This will work 100%;**

Benfield

I would say trim() is a more traditional way to deal with unwanted whitespace – Orifice

trim() only removes whitespace characters (or other characters you specify) from the beginning and end of the string. If the newline is in the middle of the string, trim() won't do anything to solve this. – Portis

Answer 4

Trouble could be in your phpMyAdmin, table wp_options, option_value.

If there is a space before the URL it will generate the ERROR: warning: header may not contain more than a single header, new line detected in...

Mcgann

Answer 5

If you encounter the "Header may not contain more than a single header, new line detected" error in your Laravel application, it's often related to how you handle redirection in your authentication middleware. This error occurs when there are multiple headers being sent to the response.

In your authentication middleware, specifically the redirectTo method, avoid using return redirect()->route('somewhere') as it can lead to this error. When you use redirect(), Laravel internally adds HTTP headers for the redirection.

protected function redirectTo($request)
{
    if (! $request->expectsJson()) {
        // return redirect()->route('signin');  <<<< this is bad
        return route('signin');
    }
}

Loewi

Answer 6

Seems like the variables you are using to create the Location attribute has a new line character in them. Pass them through urlencode()

Dupaix

I have echo my link. But there is no new line it. Below is link i have echod "Location : localhost/filethin/index.php?dir=" – Branham

Answer 7

Try encoding your URL and it should work : http://php.net/manual/en/function.urlencode.php

Pyrogenic

Answer 8

You should put the URL "http://example.com like this , please avoid "http://example.com/" "/" does give URL Mismatch , so avoid , Same problem will comes wordpress also. So try to use like this.

Holism

Answer 9

maybe you have to add in the route

'middleware' => ['auth']

in your routes/web.php

Swordbill

Answer 10

This happened to me when I copy/pasted the URL of my site in my PhpmyAdmin, when I intended to change wp_options URLs (siteurl and home).

I solved it by removing white spaces in my site URL at wp_options!

Beyrouth