Determine in php script if connected to internet?

Question

How can I check if I\'m connected to the internet from my PHP script which is running on my dev machine?

I run the script to download a set of files (which may or ma

Answer 1

<?php
function is_connected()
{
    $connected = @fsockopen("www.example.com", 80); 
                                        //website, port  (try 80 or 443)
    if ($connected){
        $is_conn = true; //action when connected
        fclose($connected);
    }else{
        $is_conn = false; //action in connection failure
    }
    return $is_conn;

}
?>

Answer 2

You could ping to a popular site or to the site you're wgetting from (like www.google.nl) then parse the result to see if you can connect to it.

<?php
$ip = '127.0.0.1'; //some ip
exec("ping -n 4 $ip 2>&1", $output, $retval);
if ($retval != 0) { 
echo "no!"; 
} 
else 
{ 
echo "yes!"; }
?>

Answer 3

This code was failing in laravel 4.2 php framework with an internal server 500 error:

<?php
     function is_connected()
     {
       $connected = @fsockopen("www.some_domain.com", 80); 
        //website, port  (try 80 or 443)
       if ($connected){
          $is_conn = true; //action when connected
          fclose($connected);
       }else{
         $is_conn = false; //action in connection failure
       }
      return $is_conn;
    }
?>

Which I didn't want to stress myself to figure that out, hence I tried this code and it worked for me:

function is_connected()
{
  $connected = fopen("http://www.google.com:80/","r");
  if($connected)
  {
     return true;
  } else {
   return false;
  }

} 

Please note that: This is based upon the assumption that the connection to google.com is less prone to failure.

Answer 4

The accepted answer did not work for me. When the internet was disconnected it threw a php error. So I used it with a little modification which is below:

if(!$sock = @fsockopen('www.google.com', 80))
{
    echo 'Not Connected';
}
else
{
echo 'Connected';
}

Answer 5

Just check the result of wget. A status code of 4 indicates a network problem, a status code of 8 indicates a server error (such as a 404). This only works if you call wget for each file in sequence, rather than once for all the files.

You can also use libcurl with PHP, instead of calling wget. Something like:

foreach (...) {
    $c = curl_init($url);
    $f = fopen($filepath, "w")
    curl_setopt($c, CURLOPT_FILE, $f);
    curl_setopt($c, CURLOPT_HEADER, 0);
    if (curl_exec($c)) {
        if (curl_getinfo($c, CURLINFO_HTTP_CODE) == 200) {
            // success
        } else {
            // 404 or something, delete file
            unlink($filepath);
        }
    } else {
        // network error or server down
        break; // abort
    }
    curl_close($c);
}

Answer 6

You can always ping good 'ol trusty google:

$response = null;
system("ping -c 1 google.com", $response);
if($response == 0)
{
    // this means you are connected
}