Try...Catch code not working. Can you see why?

Below is how I handle MySQL errors.

Basically, if the connection fails or if there's a MySQL error, the error is supposed to be logged and I am meant to be sent an e-mail. Obviously, I don't want to receive thousands of e-mails, so the e-mail is supposed to be sent only if it's been over 30 minutes (1,800 seconds) since the previous e-mail was sent. Everything works, except the e-mail, which isn't sent. And I can't work out the reason.

The two variables ($last_modified and $time_elapsed) are set, but the e-mail just isn't being sent. It's got something to do with the if statement. When I remove it, the code works.

Can anyone see the problem? Any assistance will be much appreciated.

function handle_error($err) {
throw new Exception($err);
}
try {
$con = mysql_connect("", "", "") or handle_error("mysql_connect failed! ");
mysql_select_db("") or handle_error("mysql_select_db failed! ");
$sql = "SELECT blah blah blah ...";
$result = mysql_query($sql, $con) or handle_error("mysql_query failed! ");
}
catch(exception $e) {
// Log error in error-log.txt.
trigger_error($e->getMessage() . mysql_error(), E_USER_WARNING);
// Send yourself an email if more than 30 mins (1800 seconds) have passed since previous e-mail.
$last_modified = filemtime('error-log.txt');
$time_elapsed = time() - $last_modified;
if($time_elapsed > 1800) {
error_log($e->getMessage() . "Date: " . date("l jS \of F, Y, h:i:s A") . ". File: " . $_SERVER['REQUEST_URI'], 1, "example@aol.com", "From: example@yahoo.com");
}
} 

PHP:

 

Not really sure why it doesn't work - I tested just the
$last_modified, $time_elapsed with a couple different files on the server (one old, and one newly created), and it works just fine (the if triggers if the file is older than 1800 seconds).

 

Thanks.

I can see the problem now. It's quite stupid of me.

This is what the script's doing:

1. Whenever there's an error, log it in error-log.txt.
2. Check when error-log.txt was last modified (which would always be just a split second ago).
3. Send e-mail only if $last_modified > 1,800 (which it never is).

Even if I changed the order so that the e-mail is sent before the error is logged, the script is still flawed because it would not work if errors are constantly occurring. It would send the first e-mail and that's it; it won't send one every 30 minutes.

The only way around it is to check not when error-log.txt was last modified but instead check when I last sent an e-mail.

This is my new code—and it works!

// When there's an error, log it in error file.
trigger_error($e->getMessage(). mysql_error(), E_USER_WARNING);
// Also, send self an email if more than 30 minutes have passed since previous error email.
$LastEmailSent =(int)file_get_contents('last_email_sent.txt');
$TimeElapsed = time()- $LastEmailSent;
if($TimeElapsed >1800) {
     error_log($e->getMessage()."Date: ". date("l jS \of F, Y, h:i:s A").". File: ". $_SERVER['REQUEST_URI'],1,"example@aol.com","From: example@yahoo.com");
     file_put_contents('last_email_sent.txt', time());
}

Code (markup):

 

Biggest problem I see is that this is 2014, not 2006, why are you still using the deprecated and soon to not even be supported in PHP mysql_ functions? You know, the reason for the GIANT RED WARNING BOXES in the manual? We've been told for EIGHT YEARS (pretty much since PHP 5 was introduced) to stop using them, the warning boxes were added two and a half years ago, WHY do people continue to use those inefficient and "insecure by design" functions?

Of course, if you were using PDO around two-thirds your code would throw exceptions ALL ON THEIR OWN without resorting to the "or handle_error" nonsense.