socket server 101...need some help

sneakyimp

hey everybody (especially you socket pros)!

i'm working on a super simple, general purpose php socket server to talk to flash clients. i'm hoping to make it rather generic so i can create modules to implement different multiplayer online games.

i have it working, thanks to this very helpful page, but I want to improve it. questions:

1) what does this do? it appears in the PHP file from Mr. Staub.

#!/usr/local/bin/php –q

2) What is the best way to open my php socket server? This tutorial suggests running the php file from a command line but seems to me I'd have to keep the window open which might not be so bad because I could keep an eye on it but I'm thinking I need something more self-sufficient.

Is there some kind of proper approach that can open a socket server from a browser if it hasn't been opened yet...and if it HAS been opened already, it won't try to open again or screw it up? Seems to me it would make sense to perform this in the page that hosts my client (which is going to be Flash).

Any help would be much appreciated. I expect I'll have more questions after this.

sneakyimp

ok...i found my answer to question 1.

that line apparently tells linux what to do when i just run my socket server php file from the command line. it must have the correct path to your php executable. in other words, if you put

#!/usr/bin/php

as the first line in your php file, and supposing your file is named 'socket_server.php' then you can just CD to the directory where your socket server file is and do this:

user@localbox: ./socket_server.php

and it will run.

I'm still totally unsure about question 2. Staub's article that I linked in the last post suggests perhaps making a CRON job to make sure the socket stays open.

Does anyone have any more detailed advice or experience making sockets with PHP?

AstroTeg

In Linux, you can setup a cron job to run your script. You can also use the AT command which is the task scheduler.

sneakyimp

ok...anybody know where to find some cron tutorials for dummies? i'm reading the man pages but could use some specific examples.

also, the idea of having socket code continually running somewhere invisibly gives me the heebie jeebies. i would like to keep an eye on that code. ideally this interface would be nice and easy like through a browser...or maybe i could telnet to my socket server with some kind of secret password and get an update and then watch as critical events unfold or something.

i suppose that's all in the socket server.

Will writing a log file slow a socket server down noticeably? what about running mySQL queries?

Weedpacket

Well, there's not really much to say about cron outside the man pages for cron and crontab (cron(1) describes the cron daemon, crontab(1) is a program for manipulating crontab files, and crontab(5) describes the table's format).

You specify how often the job runs, and the job. To specify the job you just write exactly the same command-line instruction you'd use if you were doing it by hand.

Each user on the computer gets their own crontab; the jobs listed therein run on the user's account (so that ordinary users can't run jobs that require root privileges, for example).

rebelo

If you're like me, you want the program to run in the background but would also like to be able to view it's console output from time to time. What you want is screen. Screen is a program which will allow you to run a program (swallowed inside a screen session) and detatch/reattach from/to that program.

Once you have it installed you just execute the following commands:

hostname$ screen <enter>
[... big long usage message about screen...hit enter ...]
* (voila, you are running inside a screen shell now)
hostname$ ./test.php <enter>
<Ctrl-A, D>
[detached]
hostname$

Now your program is gone from sight but is still running inside the screen process you started. To re-attach yourself to that screen session just type screen -r and you will be looking at the output of test.php once again.

screen rocks my world.