No cache version.
Caching disabled. Default setting for this page:enabled (code LNG204)If the display is too slow, you can disable the user mode to view the cached version.
shm_attach
(PHP 4, PHP 5, PHP 7)
shm_attach — Creates or open a shared memory segment
Description
$key
[, int $memsize
[, int $perm = 0666
]] ) : resource
shm_attach() returns an id that can be used to access
the System V shared memory with the given key, the
first call creates the shared memory segment with
memsize and the optional perm-bits
perm.
A second call to shm_attach() for the same
key will return a different shared memory
identifier, but both identifiers access the same underlying
shared memory. memsize and
perm will be ignored.
Parameters
-
key -
A numeric shared memory segment ID
-
memsize -
The memory size. If not provided, default to the sysvshm.init_mem in the php.ini, otherwise 10000 bytes.
-
perm -
The optional permission bits. Default to 0666.
Notes
Note:
This function used to return an integer value prior to PHP 5.3.0. To achieve the same value in a portable manner, the return value can be cast to an integer like:
<?php
// Create a temporary file and return its path
$tmp = tempnam('/tmp', 'PHP');
// Get the file token key
$key = ftok($tmp, 'a');
// Attach the SHM resource, notice the cast afterwards
$id = shm_attach($key);
if ($id === false) {
die('Unable to create the shared memory segment');
}
// Cast to integer, since prior to PHP 5.3.0 the resource id
// is returned which can be exposed when casting a resource
// to an integer
$id = (integer) $id;
?>
See Also
- shm_detach() - Disconnects from shared memory segment
- ftok() - Convert a pathname and a project identifier to a System V IPC key
English translation
You have asked to visit this site in English. For now, only the interface is translated, but not all the content yet.If you want to help me in translations, your contribution is welcome. All you need to do is register on the site, and send me a message asking me to add you to the group of translators, which will give you the opportunity to translate the pages you want. A link at the bottom of each translated page indicates that you are the translator, and has a link to your profile.
Thank you in advance.
Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/php-rf-shm-attach.html
The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.
References
These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.
