Keep web server working after returning output to client (in php)

I am having a PHP web page which has a button. Whenever the user click this button, an AJAX request is sent to the server, and an email is sent back to him. A notification is also displayed on the screen. (It's similar to commenti开发者_运维知识库ng on Facebook, the message is displayed, while the server keeps working to send emails).

Since sending email takes time, I want the server to return the output to the user first, then keeps working to send email.

Anyone knows how to achieve this in PHP? Thanks.

Really this is the same question as I am running through a php background process problem

And as per my answer there, if the email is taking a long time to process then there's something wrong with your MTA config.

But assuming that might be something you can't fix, you might consider sending the email using a callback invoked via register_shutdown_function() after your code does an explicit exit;

Sending an email from php shouldn't take very long, since all it has to do is send a message to the mailserver, which can take it's time sending the email after.

However, to answer your question, you can execute another php script as a background process, and have that script send the email. On a linux box it's as easy as:

exec('php phpscript.php > /dev/null &');

Which will execute phpscript.php as a background process, so that your current script won't wait for it to finish. If you want you can redirect the output somewhere other than /dev/null so you can actually view the output later.

You might need to use php-cli instead of php. Depending on how your server is set up.