On 1 Jan 2007 11:48:57 -0800,
An************@gmail.com wrote:
>I call a program through exec that can take a long time to execute.
This is fine but I would like to show some kind of animation or
something while the program is running and when it is finished letting
the user download the file.
Right now I'm using code similar to this simplified example:
----- index.php -----
<form method="post" action="genetate.php" target="_blank">
<input type="submit" value="Generate!"/>
</form>
----- generate.php -----
<?php
$tmpname = time() . md5("bla");
// Writes to $tmpname
exec("takesalotoftime $tmpname");
$len = filesize("$tmpname");
header('Content-type: application/postscript\r\n');
header("Content-Length: $len;\r\n");
header('Content-Disposition: attachment; filename="' . $tmpname
. '"\r\n');
readfile("$tmpname");
?>
So what is the best way to start the exec, show an animation until it
is finished and then send the file to the user?
One approach; show a page with an animated gif, flush the page, run the
long-running exec, then do a Javascript redirection when it's done (bearing in
mind that it's not 100% reliable).
Or move it back a step; redirect to page a with an animation and a notice to
the user to be patient, redirect to the long-running page and rely on the
browser not updating the page until the next one starts returning stuff.
If the process can provide feedback on the progress, then proc_open and
HTML_Progress from PEAR may let you get more sophisticated.
You have a few options since it looks like you're writing to a file so you can
always fetch that on a separate page - although that runs the risk of leaking
temporary files if it's not a true temp file (but if it is a true temp file
then it'd disappear anyway).
How long does it take? You may run into maximum execution time limits as well
as the users' impatience.
--
Andy Hassall ::
an**@andyh.co.uk ::
http://www.andyh.co.uk http://www.andyhsoftware.co.uk/space :: disk and FTP usage analysis tool