how to get value from php function using an array

Question

I have the following code and when i try to get a value from the array $headers nothing appears, but when I use var_dump($headers) it shows all the array values. What Am I doing wrong?

function linkcheck($url) {
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_HEADER, true);
    curl_setopt($ch, CURLOPT_NOBODY, true);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    $headers = explode("\n", curl_exec($ch));
    curl_close($ch);

    switch ($headers[18]) {
        case "Location: https://somewebsite.com/welcome":
            echo "Actice";
            break;
        case "Location: https://somewebsite.com/no_such_link":
            echo "Inactive";
            break;

    }
}

echo linkcheck('http://somewebsite.com/54sdf');

Output

array(37) {
  [0]=>
  string(19) "HTTP/1.1 302 Found
"
  [1]=>
  string(39) "Content-Type: text/html; charset=utf-8
"
  [2]=>
  string(18) "Connection: close
"
  [3]=>
  string(12) "Status: 302
"
  [4]=>
  string(60) "X-Powered-By: Phusion Passenger (mod_rails/mod_rack) 2.2.10
"
  [5]=>
  string(34) "X-UA-Compatible: IE=Edge,chrome=1
"
  [6]=>
  string(47) "Location: https://somewebsite.com/54sdf
"
  [7]=>
  string(20) "X-Runtime: 0.006921
"
  [8]=>
  string(132) "Set-Cookie: _sp_session_id=; domain=.superpoints.com; path=/; expires=Mon, 16-Jan-2012 18:08:29 GMT
"
  [9]=>
  string(24) "Cache-Control: no-cache
"
  [10]=>
  string(69) "Server: nginx/0.7.65 + Phusion Passenger 2.2.10 (mod_rails/mod_rack)
"
  [11]=>
  string(1) "
"
  [12]=>
  string(19) "HTTP/1.1 302 Found
"
  [13]=>
  string(39) "Content-Type: text/html; charset=utf-8
"
  [14]=>
  string(18) "Connection: close
"
  [15]=>
  string(12) "Status: 302
"
  [16]=>
  string(60) "X-Powered-By: Phusion Passenger (mod_rails/mod_rack) 2.2.10
"
  [17]=>
  string(34) "X-UA-Compatible: IE=Edge,chrome=1
"
  [18]=>
  string(55) "Location: https://somewebsite.com/no_such_link
"
}

Are you sure that the "keys" of the $headers array are integers? What does the print_r output of $headers look like (an example would be useful). — Jonah Bishop
– Jonah Bishop, Commented Jan 16, 2012 at 16:05
when i echo out 18 i get the value but when i place it into the switch it doesnt do anything — bammab
– bammab, Commented Jan 16, 2012 at 16:13
Try setting CURLOPT_FOLLOWLOCATION to false. It's following the redirect, so when cURL's done, the headers may be from that page instead. — gen_Eric
– gen_Eric, Commented Jan 16, 2012 at 16:15

DaveRandom · Accepted Answer · 2012-01-16 16:15:41Z

You are relying on a certain header being at a certain position, which it will not always be, and you are also not acounting for the fact the HTTP header keys are case-insensitive.

Try this:

function linkcheck($url) {

    // Do cURL
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_HEADER, true);
    curl_setopt($ch, CURLOPT_NOBODY, true);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    $response = explode("\n", curl_exec($ch));
    curl_close($ch);

    // Seperate headers from body
    $parts = explode("\r\n\r\n", $response);

    // Turn headers into associative array
    $head = explode("\r\n", $parts[0]);
    array_shift($head); // Skip response line
    $headers = array();
    foreach ($head as $header) {
        $header = explode(':', $header);
        $key = strtolower(trim(array_shift($header)));
        $val = trim(implode(':', $header));
        if (isset($headers[$key])) {
            if (is_array($headers[$key])) {
                $headers[$key][] = $val;
            } else {
                $headers[$key] = array($headers[$key], $val);
            }
        } else {
            $headers[$key] = $val;
        }
    }

    // If there is no location header, we can't test it
    if (!isset($headers['location'])) {
        echo "No location header";
        return;
    }

    switch ($headers['location']) {
        case "https://somewebsite.com/welcome":
            echo "Active";
            break;
        case "https://somewebsite.com/no_such_link":
            echo "Inactive";
            break;
        default:
            echo "Unknown value";
            break;
    }

}

Ben D · Accepted Answer · 2012-01-16 16:13:39Z

1

It looks the the issue is line breaks.

"Location: https://somewebsite.com/no_such_link
"

 !=

"Location: https://somewebsite.com/no_such_link"

remove the trailing new lines/carriage returns.

answered Jan 16, 2012 at 16:13

Ben D

14.6k3 gold badges47 silver badges59 bronze badges

Comments

anubhava · Accepted Answer · 2012-01-16 16:15:45Z

1

You need to use trim function in switch like this:

switch (trim($headers[18])) {
    case "Location: https://somewebsite.com/welcome":
        echo "Actice";
        break;
    case "Location: https://somewebsite.com/no_such_link":
        echo "Inactive";
        break;
}

It is due the face that all the lines in your headers array have an EOL at the end.

answered Jan 16, 2012 at 16:15

anubhava

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Comments

Aif · Accepted Answer · 2012-01-16 16:15:01Z

0

When I ran the test on my computer, the header size was only 7 (including two blank lines). What you should do is looking for a pattern on earch line of the headers and take action.

For instance:

foreach ($headers AS $line) {
   if (strpos('Location', $line)) {
      list ($loc, $url) = explode(':', $line);
      if ($url == 'keyword') { 
        // do stuff

      }
   }
}

If you want to manipulate headers, a good idea could be to build an associative array with headers, so that you can access an item with the protocols name (eg: $headers['location']). Just explode headers with ':' an apply an strtolower for the key. May be helpful.

edited Jan 16, 2012 at 16:15

answered Jan 16, 2012 at 16:12

Aif

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