Php run page in background

Problem
I have a form that, when submitted, will run basic code to process the information submitted and insert it into a database for display on a notification website. In addition, I have a list of people who have signed up to receive these notifications via email and SMS message. This list is trivial as the moment (only pushing about 150), however it's enough to cause it takes upwards of a minute to cycle through the entire table of subscribers and send out 150+ emails. (The emails are being sent individually as requested by the system administrators of our email server because of mass email policies.)

During this time, the individual who posted the alert will sit on the last page of the form for almost a minute without any positive reinforcement that their notification is being posted. This leads to other potential problems, all that have possible solutions that I feel are less than ideal.

1. First, the poster might think the server is lagging and click the 'Submit' button again, causing the script to start over or run twice. I could solve this by using JavaScript to disable the button and replace the text to say something like 'Processing...', however this is less than ideal because the user will still be stuck on the page for the length of the script execution. (Also, if JavaScript is disabled, this problem still exists.)

2. Second, the poster might close the tab or the browser prematurely after submitting the form. The script will keeping running on the server until it tries to write back to the browser, however if the user then browses to any page within our domain (while the script is still running), the browser hangs loading the page until the script has ended. (This only happens when a tab or window of the browser is closed and not the entire browser application.) Still, this is less than ideal.

(Possible) Solution
I've decided I want to break out the "email" part of the script into a separate file I can call after the notification has been posted. I originally thought of putting this on the confirmation page after the notification has been successfully posted. However, the user will not know this script is running and any anomalies will not be apparent to them; This script cannot fail.

But, what if I can run this script as a background process? So, my question is this: How can I execute a PHP script to trigger as a background service and run completely independent of what the user has done at the form level?

EDIT: This cannot be cron'ed. It must run the instant the form is submitted. These are high-priority notifications. In addition, the system administrators running our servers disallow crons from running any more frequently than 5 minutes.

asked Jan 7, 2011 at 15:05

Michael IrigoyenMichael Irigoyen

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5

Doing some experimentation with exec and shell_exec I have uncovered a solution that worked perfectly! I choose to use shell_exec so I can log every notification process that happens (or doesn't). (shell_exec returns as a string and this was easier than using exec, assigning the output to a variable and then opening a file to write to.)

I'm using the following line to invoke the email script:

shell_exec("/path/to/php /path/to/send_notifications.php '".$post_id."' 'alert' >> /path/to/alert_log/paging.log &");

It is important to notice the & at the end of the command (as pointed out by @netcoder). This UNIX command runs a process in the background.

The extra variables surrounded in single quotes after the path to the script are set as $_SERVER['argv'] variables that I can call within my script.

The email script then outputs to my log file using the >> and will output something like this:

[2011-01-07 11:01:26] Alert Notifications Sent for http://alerts.illinoisstate.edu/2049 (SCRIPT: 38.71 seconds)
[2011-01-07 11:01:34] CRITICAL ERROR: Alert Notifications NOT sent for http://alerts.illinoisstate.edu/2049 (SCRIPT: 23.12 seconds)

answered Jan 7, 2011 at 17:19

Michael IrigoyenMichael Irigoyen

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6

On Linux/Unix servers, you can execute a job in the background by using proc_open:

$descriptorspec = array(
   array('pipe', 'r'),               // stdin
   array('file', 'myfile.txt', 'a'), // stdout
   array('pipe', 'w'),               // stderr
);

$proc = proc_open('php email_script.php &', $descriptorspec, $pipes);

The & being the important bit here. The script will continue even if the original script has ended.

answered Jan 7, 2011 at 15:16

netcodernetcoder

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3

Of all the answers, none considered the ridiculously easy fastcgi_finish_request function, that when called, flushes all remaining output to the browser and closes the Fastcgi session and the HTTP connection, while letting the script run in the background.

Example:

 true]);
fastcgi_finish_request(); // The user is now disconnected from the script

// Do stuff with received data

Note: Due to a wontfix quirk in which calling flush() after fastcgi_finish_request will cause it to exit without warning/error.

You may wish to call ignore_user_abort(true) beforehand to supress this behavior, or simply avoid calling flush() after you've intentionally closed the connection :)

$connected = true;

// Stuff...

fastcgi_finish_request();
$connected = false;

// ...
if ($connected) {
    flush();
}

Or

ignore_user_abort(true);
fastcgi_finish_request();
// Accidental flush()es won't do harm (even if they're still technically a bug)
flush();

answered Jun 1, 2017 at 11:02

DanogentiliDanogentili

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1

PHP exec("php script.php") can do it.

From the Manual:

If a program is started with this function, in order for it to continue running in the background, the output of the program must be redirected to a file or another output stream. Failing to do so will cause PHP to hang until the execution of the program ends.

So if you redirect the output to a log file (what is a good idea anyways), your calling script will not hang and your email script will run in bg.

answered Jan 7, 2011 at 15:13

SimonSimon

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4

And why not making a HTTP Request on the script and ignoring the response ?

http://php.net/manual/en/function.httprequest-send.php

If you make your request on the script you need to call your webserver will run it in background and you can (in your main script) show a message telling the user that the script is running.

answered Jan 7, 2011 at 15:13

TwisterTwister

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The simpler way to run a PHP script in background is

php script.php >/dev/null &

The script will run in background and the page will also reach the action page faster.

LSerni

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answered Feb 7, 2013 at 12:45

1

How about this?

1. Your PHP script that holds the form saves a flag or some value into a database or file.
2. A second PHP script polls for this value periodically and if it's been set, it triggers the Email script in a synchronous manner.

This second PHP script should be set to run as a cron.

answered Jan 7, 2011 at 15:09

adarshradarshr

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1

As I know you cannot do this in easy way (see fork exec etc (don't work under windows)), may be you can reverse the approach, use the background of the browser posting the form in ajax, so if the post still work you've no wait time.
This can help even if you have to do some long elaboration.

About sending mail it's always suggest to use a spooler, may be a local & quick smtp server that accept your requests and the spool them to the real MTA or put all in a DB, than use a cron that spool the queue.
The cron may be on another machine calling the spooler as external url:

* * * * * wget -O /dev/null http://www.example.com/spooler.php

answered Jan 7, 2011 at 15:25

Ivan ButtinoniIvan Buttinoni

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Background cron job sounds like a good idea for this.

You'll need ssh access to the machine to run the script as a cron.

$ php scriptname.php to run it.

answered Jan 7, 2011 at 15:08

IanIan

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2

If you can access the server over ssh and can run your own scripts you can make a simple fifo server using php (although you will have to recompile php with posix support for fork).

The server can be written in anything really, you probably can easily do it in python.

Or the simplest solution would be sending an HttpRequest and not reading the return data but the server might destroy the script before it finish processing.

Example server :

Example client :

21, 'yy' => array(1,2,3)));
}
?>

answered Jan 7, 2011 at 16:26

OneOfOneOneOfOne

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If you're on Windows, research proc_open or popen...

But if we're on the same server "Linux" running cpanel then this is the right approach:

#!/usr/bin/php 
&1 & echo $!");
While(exec("ps $pid"))
{ //you can also have a streamer here like fprintf,        
 // or fgets
}
?>

Don't use fork() or curl if you doubt you can handle them, it's just like abusing your server

Lastly, on the script.php file which is called above, take note of this make sure you wrote:

answered May 9, 2014 at 19:47

1

Assuming you are running on a *nix platform, use cron and the php executable.

EDIT:

There are quite a number of questions asking for "running php without cron" on SO already. Here's one:

Schedule scripts without using CRON

That said, the exec() answer above sounds very promising :)

answered Jan 7, 2011 at 15:08

Spiny NormanSpiny Norman

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1

for background worker i think you should try this technique it will help to call as many as pages you like all pages will run at once independently without waiting for each page response as asynchronous.

form_action_page.php

testpage.php

     testValue
//here do your background operations it will not halt main page
    ?>

PS:if you want to send url parameters as loop then follow this answer :https://stackoverflow.com/a/41225209/6295712

answered Dec 19, 2016 at 15:42

Hassan SaeedHassan Saeed

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0

In my case I have 3 params, one of them is string (mensaje):

exec("C:\wamp\bin\php\php5.5.12\php.exe C:/test/N/trunk/api/v1/Process.php $idTest2 $idTest3 \"$mensaje\" >> c:/log.log &");

In my Process.php I have this code:

if (!isset($argv[1]) || !isset($argv[2]) || !isset($argv[3]))
{   
    die("Error.");
} 

$idCurso = $argv[1];
$idDestino = $argv[2];
$mensaje = $argv[3];

answered Jun 23, 2015 at 18:58

This is works for me. tyr this

exec(“php asyn.php”.” > /dev/null 2>/dev/null &“);

answered Aug 25, 2018 at 10:22

1

Use Amphp to execute jobs in parallel & asynchronously.

Install the library

composer require amphp/parallel-functions

Code sample

';

$promises[1] = ParallelFunctions\parallel(function (){
    // Send Email
})();

$promises[2] = ParallelFunctions\parallel(function (){
    // Send SMS
})();


Promise\wait(Promise\all($promises));

echo 'finished';

Fo your use case, You can do something like below

answered Apr 21, 2020 at 8:14

SkyRarSkyRar

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