Browser times out while waiting for while loop

Anon

I'm writing a broadcast email application in php to send our customers messages.

Very simply program...gets email addresses from MySql then uses a while loop and the mail() function to send the same message to all the addresses returned in the query.

I thought this would be a breeze but I'm haveing a problem.....even though the mail() function processes each email quickly, I have over 400 addresses to send mail to....and this list will be getting larger.

As the while loop is sending out the mail...
while (still addresses) {
send mail;
}

my browser is just sitting there...waiting for the loop to finish.

Before the program can finish, my browser times out and I think the program stops it's execution...not sure about that but I do know that not all the mail was sent.

The root of my question is this....how can you keep a browser from timing out and preferably give some sort of progress report, as a time consuming process is being executed?

I'm hoping there will be a simple answer to this problem. I can think of several ways to off load the actual 'sending' of the emails to a perl script but I would prefer to do this job in PHP.

Thanks,
Chuckc

Anon

how are you making a check on 'still addresses'? may be you are not decrementing the ammount of the addresses in the loop, which is causing it to go on forever.

try to give it a count, e.g. get the total number of rows, and the simply use FOR loop untill it matches the total number of rows.

hope that helps.

Anon

$result = mysql_query("SELECT email FROM customers");

for ($i = 0; $i < count(mysql_num_rows($result); $i++😉 {
$email = mysql_fetch_row($result);
if(mail ("$email", "A message from us!", "This is a....")) {
echo "$i) Sent To: $email ";
}
else {
echo "$i>Failed Send to: $email ";
}
}

somewhere thereabouts... -g

Anon

oops sorry, made an error
$result = mysql_query("SELECT email FROM customers");

for ($i = 0; $i < count(mysql_num_rows($result); $i++😉 {
$email = mysql_fetch_row($result);
if(mail ("$email", "A message from us!", "This is a....")) {
echo "$i) Sent To: $email ";
}
else {
echo "$i>Failed Send to: $email ";
}
}

Anon

HI,

Thanks for the reply...

The loop does not go on forever..only until the the query runs out of email addresses.

The problem is: even if it only taks 1/2 second to send each email, the program will still take almost 4 minutes to run.(over 400 addresses to process)

During this time...while the emails are chugging away and going out...my browser is spinning and spinning until it times out.

If you have ever gone to a URL that was not up...you know what I'm talking about. In my case the url is up and the program is working but I don't think PHP actually returns anything until AFTER the entire program completes....thus, my browser thinks there is no reply from the page...time out. Oh no.

It seems like there should be a way to send information to your browser DURNIG the exectution of a program. That way, even if you had a really big job to do, your browser would not just site there but display some progress info.

Any ideas?

Thanks,
Chuckc

Anon

if you take a look at my code, after each loop, it ouputs either Sent to: and their email address or highlights in red and outputs Failed to Send: and their email address... if you have 400 emails to send you'll get 400 lines on your browser it will update after every loop... -g

Anon

Hi again,

I did not notice that the 1st time through that you had put in the echo statements. However, I did try something like that with my code.

I put in a print statement that printed every tenth line. It seems though, that even though I am printing every tenth line, it does not actually 'display' any output until the completion of the entire program.

Is this a quirk with PHP. its seems to be the same with both Netscape and Internet Explorer.

If you have a few minutes, give it a try...here is a simple test program that I wrote:

<?
print "start program \n";
sleep(3);

print "three seconds past...still going \n";
sleep(3);

print "three seconds past...end program \n";
?>

If you run this program you will see that it does not print a line every three seconds..instead, it waits until the entire program completes...about 9 seconds...and them prints all 4 messages at once.

Any ideas how to get around this??

Chuckc

Anon

Try using flush().

It forces the web server to push the information down to the client immediately. One problem you might want to note is that this function only seems to work on IE when the amount in the buffer is significantly large enough (maybe a few lines?).

Try something like this:-

(... send out a <title> etc here first ...)
<?

while($getrow = mysql_fetch_array($result)) {
mail("$reciever", "$subject", "$content", "From: $sender");
printf("sending to %s", $reciever);
flush();
}

Anon

Actually I have had no problem using flush()

the problems with flush are not due to the PHP it is the browser, if you use a text format for your output flush will work flawlessly, it is because the Browser assumes it is waiting for HTML, the rendering engine has to sit and wait for something important like </table> or as such so that it can completly and properly display the HTML page. But seeing as you are just needing an output of lines just do a text file format like

header("Content-Type: text/plain");

flush() will then work properly for either browser.

Jay
www.shoutclub.com

Anon

I just tried to use the header function with flush and plain text as you suggested...I still had problems. The code works with Netscape every time. It won't work with IE5 when you first call the page but it will for any REFRESHES that you do...the code I tried is below. Any suggestions?

Thanks..chuckc

<?
header("Content-Type: text/plain");

print "Start here\n";
flush();
sleep(2);
print "two seconds have passed\n";
flush();
sleep(2);
print "two seconds have passed\n";
flush();
sleep(2);
print "all done\n";

Anon

Chuck, did you ever find an acceptable solution to this problem? I'm doing the exact same thing (looping and sending email), and am looking for a similar solution. I need it to work in IE more than Netscape, though.

Anon

I am using the flush command which seems to work...with one exception. With IE, the flush command does not work on the initial page load. However, if you 'refresh' the page, then it does work.

After the 'mail' command, I hadded a
print $email_address;
flush();

Funny though, the last time I ran the program, it worked in IE without having to refresh the program.

Chuckc

Anon

Cool, I got it. I made a little progress bar. It prints out the current progress of the loop in increments of ten percent. Maybe this code would be useful to someone else:

print("Doing loop... ");
flush();
$intPercent = 0;

while(...) {

$i++;
$intRoundPercent = round(($i/$intSubscribers)*100);
if(($intRoundPercent % 10 == 0) && ($intRoundPercent > $intPercent)) {
$intPercent+=10;
print("$intPercent%... ");
flush();

}

print("Loop complete.");
flush();