I am working on a site that require a php script running on a server without any request,
it is a bot script that keeps (not full time but at least once a day) checking client accounts and send alert messages to clients when something happens.
any ideas are appreciated.
Assuming you need to do this on linux, you may run any php script from the browser and from the CLI as well.
You may run a simple php script:
<? echo "Ana are mere"; ?>
like this:
php -f ./index.php
Be careful about file-permissions, and any bug that may creep inside your code, memory leaks or unallocated variables will become VERY visible now, as the process will run continuously.
If you dont want it running in the background all the time, take a look at crontab (http://unixgeeks.org/security/newbie/unix/cron-1.html) to be able to start jobs regularly.
-- edit--
take a look at php execute a background process and PHP: How to return information to a waiting script and continue processing
Basically you want to start a background process, and you may do this by either using exec() or fsockopen() or a file_get_contents() on your own script probably in this order, if don't have access to exec, or socket functions.
Also take a look at http://us2.php.net/manual/en/function.session-write-close.php so the "background script" won't "block" the request and http://us2.php.net/manual/en/function.ignore-user-abort.php
Use a cron job to do it http://www.cronjobs.org/
You can automatically call a script at any interval you like indefinitely. Your hosting provider should support them if they are good.
You should also consider putting a unique key on the end of the page
ie. www.yoursite.com/cronjob.php?key=randomstring
and then only run the script if the key is correct, to prevent bots and other users from running the script when you don't want it run.
If you can't create a cron job, then create a page that does what you want and create a scheduled task on another machine (maybe your PC?) that just goes out and hits that page at a certain time every day.
It's really a hack, but if you absolutely can't set up a cron job, it would be an option.
As Evernoob and Quamis said, you want to have a cron job (UNIX/Linux/Mac OS) or a scheduled task (MS Windows). Furthermore, you can either have the PHP script run using the PHP command line interface (CLI), in which case you can invoke the PHP executable and then your script name. As an alternate, you can use a tool like wget (availble on all platforms) to invoke the PHP script as if someone had typed the URL in the location bar of a web browser.
A php script could not be used like you imagine here. Because it's executed through apache after a request from somewhere.
Even if you do while(1) in your script, apache/php will automaticly stop your script.
Responding to your comment, yes you'll need ssh access to do this, except if your web interface allow you to add cronjob.
Maybe you can write a service which can be executed with a program on another server and do the job.
If you have no access to the server the easiest way would probably be to hit it through the browser, but that would require you or an external script hitting the URL at the same interval each day when you wanted it to one. You may also be able to setup a Selenium test suite that runs locally on a schedule and hits the page. I'm not 100% if that's possible with Selenium though, you may need some 3rd-party apps to make it happen.
Something else you could try would be to see about using PHP's Process Control Functions (link). These will let you create a script that is a deamon and runs in the background. You may be able to do this to keep the script running on the server and firing off commands at programmed intervals. You will still need some way to get it running the first time (browser request or via command line) though.
Related
I have tried reading and have understood PHP console to be a command-line interface (CLI) like one used in composer. I do not understand the difference between a web script and a console script. I do not see the use of having the two.
I want to crawl data from a certain link. Should I use a console script or web script and why?
Please explain in the simplest manner possible.
There is no difference between the two. In most instances, the same PHP script will run whether you execute it from the command line or via the web.
There is, however, a difference between the environment the script will execute within. A CLI script is initiated from and executed within your shell on your computer. It is very self-contained. A web script, on the other hand, is (typically) initiated via a HTTP request from a browser, passes over the web to a web server, is executed on that remote server and a result (typically a web page) is passed back to your browser. In the latter case, there are special environment variables related to the web request made available to the script.
It's a bit hard to know which is the best case for your web crawler script without knowing more detail. But I'd say a command line script is what you're after.
One difference between a web page and a CLI instance is the way the script is executed: webpages will be loaded via a web container, while CLI's will be usually executed by the shell used to launch the PHP. Due to this, a CLI might not have access to all $_SERVER variables as the webpage as practically there is no HTTP request involved.
CLI scripts are useful for doing background tasks that are not initiated by the web server, for example a cron job that periodically cleans your database, on one that executes queued jobs. Think of CLI as shell scripts, you can write a PHP script instead of a bash one.
The PHP interpreter is the same in both cases, and it's up to you to decide which one suits best your needs: webpages are more common, however if you need to have you server do some work without waiting for a web request, the you can go with CLI.
Well, basically a console script is the way for your task.
The difference resides in the fact a Webscript will block your browser, will not show your progress real-time, etc.
I was able to crawl and download about 6000 images from my beloved anime with a console script, showing the progress status, something harder with a Web script as the browser will cache the output. Also you can chain your script and also make some cron magic(assuming you are on nix box)
I'm having a problem where putty gets regularly disconnected. So, when I run a PHP script from the terminal, it always gets interrupted. The script is supposed to run several hours, so I'm not having any luck with it.
How can I completely run this from the server side? I'm reading about cron jobs, but I'm having a hard time understanding at this time. Is there any alternative to cron for what I need?
I have several script PHP files that need to be run, one by one, or perhaps two at a time. Any ideas?
You don't need to leave it run in a cron job - you can just run the php script inside a screen.
Simply type;
screen php /path/to/myphpscript.php
A screen will continue running even after you disconnect from PuTTY. If you need to check up on it, you can use;
screen -r
To re-attach yourself to this process, and view any output.
You need to prevent the process from terminating when the session disconnects.
Something like this would work:
nohup php myscript.php
You can create a cron job to start the php script periodically based on a list of time tasks. More info. You could also start the task in the background from the console. i.e. php-cgi script.php& this would make the script a background task
Take a look at GNU Screen; it allows you to detach and reattach a session later, which is perfect for long-running scripts. Cron is a good option if you want it to happen in a recurring fashion; one-off batch jobs can be scheduled with something like at. For more intense computing needs, you might want to look into a more full-fledged job scheduling system like TORQUE.
You can run your program in background
php ./yourscript.php &
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 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 written a PHP script which generates an SQL file containing all tables in my database.
What I want to do is execute this script daily or every n days. I have read about cron jobs but I am using Windows. How can I automate the script execution on the server?
You'll need to add a scheduled task to call the URL.
First of all, read up here:
MS KB - this is for Windows XP.
Second, you'll need some way to call the URL - i'd recommend using something like wget - this way you can call the URL and save the output to a file, so you can see what the debug output is. You can get hold of wget on this page.
Final step is, as Gabriel says, write a batch file to tie all this up, then away you go.
e: wget is pretty simple to use, but if you have any issues, leave a comment and I'll help out.
ee: thinking about it, you don't even really need a batch file, and could just call wget directly..
add a scheduled task to request the url. either using a batch file or a script file (WSH).
http://blog.netnerds.net/2007/01/vbscript-download-and-save-a-binary-file/
this script will allow you to download binary data from a web source. Modify it to work for you particular case. This vbs file can either be run directly or executed from within a script. Alternately you do not have to save the file using the script, you can just output the contents (WScript.Echo objXMLHTTP.ResponseBody) and utilize the CMD out to file argument:
cscript download.vbs > logfile.log
save that bad boy in a .bat file somewhere useful and call it in the scheduler: http://lifehacker.com/153089/hack-attack-using-windows-scheduled-tasks
Cron is not always available on many hosting accounts.
But try this:
http://www.phpjobscheduler.co.uk/
its free, has a useful interface so you can see all the scheduled tasks and will run on any host that provides php and mysql.
You can use ATrigger scheduling service. A PHP library is also available to create scheduled tasks without overhead. Reporting, Analytics, Error Handling and more benefits.
Disclaimer: I was among the ATrigger team. It's a freeware and I have not any commercial purpose.
Windows doesn't have cron, but it does come with the 'at' command. It's not as flexible as cron, but it will allow you to schedule arbitrary tasks for execution from the command line.
Yes, You can schedule and execute your php script on windows to run automatically. In linux like os u will have cron but on windows u can schedule task using task scheduler.
If your code is in remote hosted server then create a cron-job for the same.
Else if in local then use a scheduled task in windows.Its easy to implement.I am having servers with so many scheduled tasks running.