PHP and cURL in Amazon EC2 in www folder

PHP and cURL work fine in a non-webfacing directory in my amazon EC2 micro install, 12.04.2 LTS (GNU/Linux 3.2.0-40-virtual x86_64).

I'm able to run some scripts on the command line using cURL:

    #!/usr/bin/php
    $command = '/absolute/path/to/running/process';
    $url = 'http://example.com';
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT , 400);
    curl_setopt($ch, CURLOPT_TIMEOUT, 400);

    $resp = json_decode(curl_exec($ch), 1);
    $data1 = round($resp["data1"], 6);
    $data2 = round ($resp["data2"], 2);

    curl_close($ch);


    $c = array(
            'var1' => trim(shell_exec($command)),
            'var2' => trim(shell_exec($command)),
            'var3' => trim(shell_exec($command)),
            'var4' => number_format($data1, 6, '.', ''),
            'var5' => number_format($data2, 0, '.', ',')
    );
    var_dump($c);

This works fine.

However, as soon as I put this same script in the web facing directory (I remove #!/usr/bin/php obviously), the page loads (I can type echo 'Hello World!' at the very top and see the text on a browser from a remote machine), but the page is entirely blank and adding echo statements after curl results in nothing. If I comment out the curl function calls and try to simply execute the command, it seems to not work (The entire array of values is populated with NULL or 0.).

• What's going on with PHP? Why won't cURL run in the /var/www/ folder but runs fine everywhere else? I'm storing information to a database using cURL to get some JSON from public APIs.
• Why can't I use shell_exec to run a script as I normally could using PHP on the command line?
• Errors aren't showing up in PHP even though error_reporting(E_ALL) is set. I can't find a log of errors by using locate to find error_log or php.err, which I thought were the default names for the php error log.

I feel like these two issues may be related, but I can't figure out why, maybe permissions? Something I noticed was that I cannot create or modify files in this directory without using the sudo command, which isn't usual.

Another note: phpinfo() says nothing about cURL, but it works on the command line. I'm not sure why.