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.

Rechercher une fonction PHP

shmop_open

Contents

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

shmop_open — Create or open shared memory block

Description

shmop_open ( int $key , string $flags , int $mode , int $size ) : resource

shmop_open() can create or open a shared memory block.

PHP: shmop_open - Manual Home of Manuel PHP  Contents Haut

Parameters

key

System's id for the shared memory block. Can be passed as a decimal or hex.

flags

The flags that you can use:

  • "a" for access (sets SHM_RDONLY for shmat) use this flag when you need to open an existing shared memory segment for read only
  • "c" for create (sets IPC_CREATE) use this flag when you need to create a new shared memory segment or if a segment with the same key exists, try to open it for read and write
  • "w" for read & write access use this flag when you need to read and write to a shared memory segment, use this flag in most cases.
  • "n" create a new memory segment (sets IPC_CREATE|IPC_EXCL) use this flag when you want to create a new shared memory segment but if one already exists with the same flag, fail. This is useful for security purposes, using this you can prevent race condition exploits.

mode

The permissions that you wish to assign to your memory segment, those are the same as permission for a file. Permissions need to be passed in octal form, like for example 0644

size

The size of the shared memory block you wish to create in bytes

Note:

Note: the 3rd and 4th should be entered as 0 if you are opening an existing memory segment.

PHP: shmop_open - Manual Home of Manuel PHP  Contents Haut

Return Values

On success shmop_open() will return an resource that you can use to access the shared memory segment you've created. FALSE is returned on failure.

PHP: shmop_open - Manual Home of Manuel PHP  Contents Haut

Changelog

Version Description
7.0.0 The return type of shmop_open() has been changed from int to resource.

PHP: shmop_open - Manual Home of Manuel PHP  Contents Haut

Examples

Example #1 Create a new shared memory block

<?php
$shm_key = ftok(__FILE__, 't');
$shm_id = shmop_open($shm_key, "c", 0644, 100);
?>

This example opened a shared memory block with a system id returned by ftok().

PHP: shmop_open - Manual Home of Manuel PHP  Contents Haut

See Also

Find a PHP function

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-function.shmop-open.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

  1. View the html document Language of the document:fr Manuel PHP : http://php.net

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.

Contents Haut