Shared memory between scripts ? shmop etc... help !

[Patricio Stegmann]

Hi,
I am trying to develop a very basic but portable chat engine with php.
I would like to develop it without any database or filesystem stuff,
because I want it very portable and easy to install. So I was looking
for a way to make scripts communicate, or keep a kind of state . So
someone told me to look for shared memory operations... shmop_open and
all this things.... but I cant seem to find a script that uses this,
or something that works...
I tried some examples (always same ones) on different phpsites, like
creating a shmop object, writing on it then reading from it, all in
the same script... what i would like to do is slightly different; have
a writer page, and a reader page, then i could do some kind of chat
..... the writer page would be the textsubmitter stuff... the reader
page would be an autoreloading page ... then with some simple
parameters I could finalize a very simple chat, pluggable anywhere ...
so ... When I do a write page, it works, but when I try to read, on
another script, with for example this:

<?
$shm_id = shmop_open(0xff 3, "a", 0644, 100);
echo $shm_id;
?>


0xff3 being the place where i created on the wrietr page ... then i
get:


Warning: shmop_open(): unable to attach or create shared memory
segment in /var/www/localhost/htdocs/chat/read.php on line 2



So I dont understand why it doesn't work !

Thanks for your attention


Patricio Stegmann

[Colin McKinnon]

Re: Shared memory between scripts ? shmop etc... help !

Patricio Stegmann wrote:
[color=blue]
> another script, with for example this:
>
> <?
> $shm_id = shmop_open(0xff 3, "a", 0644, 100);
> echo $shm_id;
> ?>
>
>
> 0xff3 being the place where i created on the wrietr page ... then i
> get:
>
>
> Warning: shmop_open(): unable to attach or create shared memory
> segment in /var/www/localhost/htdocs/chat/read.php on line 2
>[/color]

I'd recommend only every (re) creating the key using ftok(). But why are you
bothering with shm at all? If you control both ends of the system on a
Unix/Linux box there's very little overhead in using a real file.

HTH

C.

[Chung Leong]

Re: Shared memory between scripts ? shmop etc... help !

"Patricio Stegmann" <kpoman@hotmail .com> wrote in message
news:18ca5147.0 406230409.4bf87 f82@posting.goo gle.com...[color=blue]
> Hi,
> I am trying to develop a very basic but portable chat engine with php.
> I would like to develop it without any database or filesystem stuff,
> because I want it very portable and easy to install. So I was looking
> for a way to make scripts communicate, or keep a kind of state . So
> someone told me to look for shared memory operations... shmop_open and
> all this things.... but I cant seem to find a script that uses this,
> or something that works...
> I tried some examples (always same ones) on different phpsites, like
> creating a shmop object, writing on it then reading from it, all in
> the same script... what i would like to do is slightly different; have
> a writer page, and a reader page, then i could do some kind of chat
> .... the writer page would be the textsubmitter stuff... the reader
> page would be an autoreloading page ... then with some simple
> parameters I could finalize a very simple chat, pluggable anywhere ...
> so ... When I do a write page, it works, but when I try to read, on
> another script, with for example this:
>
> <?
> $shm_id = shmop_open(0xff 3, "a", 0644, 100);
> echo $shm_id;
> ?>
>
>
> 0xff3 being the place where i created on the wrietr page ... then i
> get:
>
>
> Warning: shmop_open(): unable to attach or create shared memory
> segment in /var/www/localhost/htdocs/chat/read.php on line 2
>
>
>
> So I dont understand why it doesn't work ![/color]

Resources are freed automatically when a script terminates, duh!