I have a web page with a button, when I click the button I want it to post data to a php file - I'm fine with this bit. The problem is that I want that PHP file to then start a process on the server unrelated to the httpd, so if I close the web page that PHP script will still be running to the end (Its a long running script).
The long running script does various tasks that take a while, it will be writing the progress to a .json file. I have my JavaScript setup on the webpage to read the progress every second and update the progress bars etc... I want it so that even if I close the web page the script will still be running to the end, this way I can come back whenever and check on the progress etc.
I've been reading around and found mostly people are saying to use exec but that isn't working for me (although I am testing on windows under wamp, maybe that is why?)
I have been told that I should either by using a manager process running on the server (not through apache) or to use POSIX signals. I'm not to sure on any of these so any help would be appreciated, be it explanation, code or links to good articles
I'd like the keep the script setup how it is if possible, so I only need to figure out how to start a background process not on the httpd.
I thank you all in advance,
Ben
I found this suggestion in a comment on PHP website.
pclose(popen("start /B ". $cmd, "r"));
Related
I have a windows pc with apache running, and I needed a php script to continuously run to listen to inputs coming from a UDP port, and take the required action and send it back.
The only way I know how to do this, is to install curl for cmd, and run the php script with a WHILE loop. What I am afraid is that this is the wrong way to do it.and may be unreliable and take up large amount of system resources.
Can people comment on the above method? I have heard of cron..but thats for unix only? What can I do?
Hey try this below solution.
Use a bat file and schedule to execute that bat file.
For example in the bat file executephp.bat, write this
c:\xampp\php\php.exe -f c:\xampp\htdocs\do_something.php
save that bat file that contains that line.
Go to windows scheduler and create a new task and in action tab, browse to point that executephp.bat and for start in -> direct to the directory u have that executephp.bat.
For example if u save the file under C:\xampp\htdocs put that C:\xampp\htdocs in the start in.
Remember to invoke the script even when the user is not logged on.
Everything is set and it will execute without problem.
A PHP script behind Apache will always have a maximum execution time, so the while-loop should always be stopped after the specific timeout.
You should better use cron or a batch script like Venkat recommended. There are some great services for cron out there, that will do a GET request to your server and run the script. Have a look at this related thread: Scheduled Request to my website from an external source
Doesn't that fit your needs?
is it possible to launch a php script in background on the webserver with js and let it run even if you change page or not visit the site at all and then get the current status if you call the php script in a second moment?
This php script will process data for hours and sleep for X seconds/minutes for each loops. If what I asked before is possible how can I even get "echos" from it if php will only generated an output only when the script ends?
Maybe this is not a job for PHP?
thank you
EDIT: on a windows machine with apache
It certainly is possible - I have several scripts that run 24/7 written in PHP. Check out Creating Daemons in PHP. It has good info on how to 'daemonize' a php script so that it will run like a service, and it also covers signal handling.
To get debugging output you would redirect to a log file. Do a search on "unix redirect output" as there is a lot of info available.
In Windows it's not much different from UNIX.
First of all, you need to create a PHP script with a run loop. For example, take a look at this: http://code.google.com/p/php-apns/ . This is a PHP "daemon": the main script, PushMonitor.php, runs forever, because it has an infinite loop. It polls a queue at regular intervals, then execute the actions and then wait. Really simple, actually!
The problem, in your case, is that you want to launch the "daemon" from a PHP script.
You may want to look at this: http://robert.accettura.com/blog/2006/09/14/asynchronous-processing-with-php/ (first example code) . You will execute something like launchBackgroundProcess('php myscript.php') .
Note that on the code there's the "start /b" command (and the "&" at the end of the command for UNIX). That is important, because otherwise your process would be killed when the PHP script of the web page is terminated (children process die after parent dies!).
Also, remember that the "php" executable (cli) must be in your path (so you can execute "php" from the command line).
Since the PHP script of the page launching the background process is going to terminate, you can't directly catch the "echoes" in a simple way. My suggestion is to write all output to a file (or a database etc), and then read the contents from that source when necessary.
So, instead of "echo", you will use file_put_contents() etc.
i am working on web Payroll project using symfony framework. we have 27000 employees to process every month. when we doing employee payroll process we can not depend on browser request as it is a long time taking process and server time out coming. as a work around we like to execute the php script from the background on linux server. then even browser closed the scripts can excute the background.
what is the best way to do this task please help
More info
we would like to give the pay roll process start button from the web interface when user click on the button pay roll process should start even browser close it should execute until done from the background.
regards
To run in the backgroud do the following steps:
Wrap your php command in a shell script:
**
#!/usr/bin/bash
# set up environment variables, PATH etc. here
php /home/yourapp/yourscript.php
**
Code up a web page/php script to request the start.
In the script you need the line:
system('/home/yourapp/yourscript.sh > scriptlog.txt &'
You probably need an extra link to browse the "scriptlog.txt" file from the web.
There are different ways to handle this problem.
The first way is to execute , startinan shell command in background (and with using nohup if you like) starting from your PHP code. Thats nearly the same think like the first answer in the duplicate question.
The 2nd way is to use PHP PCNTL Feature.
Using PCNTL you can create child processes, which running in background. So it's possible to make an fork and returning to the user: "pay roll process is running - you will get an mail, if the system is ready".
i start a linux console app from my php5 script, it starts ok but then termintates. I've tried using system(), shell_exec and tried starting as background process but to no avail it starts and then quits.
What i am trying to achieve is from a remote browser start a console app using a php5 script and then it should remain running (just as it would if i started it from a bash shell) , i then want to send commands (from a bash shell it would be keyboard strokes) to the console app from another set of php5 scripts. Hope its clear what i am trying to do.
If anyone could give some info on the best way about doing this, as i think i may have something fundamentally wrong.
I have a Debian Lenny box running apache.The console app is just a simple program that prints to stdout and reads from stdin.
How do you expect to send input to this app? Where is it listening for input?
It simply may only support interactive use, and exit as a result of that. Or, even simpler, it may terminate because it sees that is has no input (nothing piped in or nothing from some file) and since it's not connected to an interactive shell, it has nothing to do. There's no point in waiting for input from a user that doesn't have a way to interact w/ the application.
On every request, PHP starts up, compiles your script and executes it. After execution, the script exists. When the script exits, all of the resources it was using, including file handles, database handles, and pipes to other programs are terminated.
You're going to need to find another way to keep your program open and have PHP communicate with it. Otherwise, every request to your script is going to open a new copy of the program, and then both will exit when the PHP script is complete.
Unfortunately without knowing what the program is, it will be hard to offer suggestions on how to go about doing this.
I have two problems which are related.
1) I have a batch file that contains this:
net stop wampapache
net start wampapache
Which tries to stop and start my wamp server. When I double click the stop.bat file with the above it works successfully. When I try to run that from my PHP script, it stops the server but doesn't start it fully which I am guessing is because Apache is waiting for that PHP process to exit?
function php_kill(){
exec('stop.bat', $output = array(), $return);
return $return;
}
2) Is there a way to restart my webserver (apache) whilst keeping session variables that PHP needs available?
Thanks all
The PHP process is killing a process that, in turn, kills the PHP process. It's like going back in time and murdering your parents before they gave birth to you. I don't see how it can work.
One has to ask why this functionality is necessary. If you must do it this way, you should look into scheduling a service restart from the script. I don't know if this is possible via PHP and Windows.
The problem is related to the fact that exec waits for the process to end, but the process actually kills PHP so the whole thing gets stuck.
Running stop.bat as a background process should fix it. (here how to run a background process on Windows)