PHP Code not Working on Remote Server

Question

I am having some trouble with a few lines of PHP code when I upload it to my domain over ftp. The lines below work on my local server on XAMPP but when I upload it to the remote server through my hosting client, instead of echoing out what it is supposed to, I get a blank page with no error log or message displayed. Any help would be greatly appreciated and thank you for taking the time to answer my question.

Code that doesn't work:

<?php

function getDominantColour($image, $type='png')
{


    eval('$source = imagecreatefrom' . $type . '("' . $image . '");'); 
    $source_x = imagesx($source); 
    $source_y = imagesy($source); 
    $resized_x = 100; 
    $resized_y = 100; 
    $resized= imagecreatetruecolor($resized_x, $resized_y); 
    imagecopyresampled($resized, $source, 0, 0, 0, 0, $resized_x, $resized_y, $source_x, $source_y);


    $colours = array();
    $rgb = '';
    $index = array();
    for ($x=0; $x<100; $x++) 
    {
        for ($y=0; $y<100; $y++)
        {
            $rgb = imagecolorat($resized, $x, $y); 
            $index = imagecolorsforindex($resized, $rgb); 
            $key = 'R' . $index['red'] . 'G' . $index['green'] . 'B' . $index['blue']; 
            if (empty($colours[$key])) 
            {
                $colours[$key] = 1;
            } else { 
                $colours[$key]++;
            }
        }
    }
    arsort($colours, SORT_NUMERIC);
    return key($colours);
}


echo(getDominantColour("http://maps.googleapis.com/maps/api/staticmap?center=40.727404,-74.020862&zoom=50&size=600x300&maptype=roadmap&markers=color:blue&sensor=false"));

?>

And when you turn on error reporting, what happens then – Ohgodwhy Apr 27 '14 at 18:47 — Ohgodwhy, Apr 27 '14 at 18:47

score 2 · Accepted Answer · edited May 23 '17 at 12:22

2

eval is evil ( not always ). But in your example i would try to avoid it.

In your code you could use call_user_func instead:

$source = call_user_func( 'imagecreatefrom' . $type, $image );

As if on this question explained:

Sometimes eval is the only/the right solution.

For most cases one should try something else.

If unsure, goto 2.

Else, be very, very careful.

edited May 23 '17 at 12:22

Community

1
1

answered Apr 27 '14 at 21:27

Mario

3,339
2
22
41

1

Thanks so much for your help. I changed it so that eval is no longer used but I also learned that the hosting client I have did not have support for the GD library turned on. These two put together fixed the problem. Thanks so much again for your time and help! – Arun Kalyanaraman Apr 27 '14 at 22:30

score 1 · Answer 2 · answered Apr 27 '14 at 18:47

1

eval is banned from lots of servers as a security precaution. Rewrite your code so that you don't use that function.

answered Apr 27 '14 at 18:47

Alex Stylianos

84
2

Really ? eval function is disabled? been with a ton of hosts, never seen that one. Ahh, I see tons of Free Web Hosts disable this function now, interesting. Thanks. – Ohgodwhy Apr 27 '14 at 18:47
How would you recommend that I change the code so that the eval function is not used. Thanks again for your time and help! – Arun Kalyanaraman Apr 27 '14 at 19:10
@user2484406 can't you just use a switch to decide which `imagecreatefrom` function to call depending on the `type`? – tim Apr 27 '14 at 19:19
I changed that since the image will always be a png but it still doesn't work. Is there a specific command or function that wont work on a remote server or hosting client that I used? Thanks for your help! – Arun Kalyanaraman Apr 27 '14 at 20:00
Put `error_reporting(E_ALL);` on top of your script, see what error it gives you. – Alex Stylianos Apr 27 '14 at 20:41

PHP Code not Working on Remote Server

2 Answers2