msg_queue_exists

(PHP 5 >= 5.3.0, PHP 7)

msg_queue_exists — Check whether a message queue exists

说明

msg_queue_exists ( int $key ) : bool

Checks whether the message queue key exists.

参数

key

Queue key.

返回值

成功时返回 TRUE， 或者在失败时返回 FALSE。

参见

User Contributed Notes

klatovsky at 2u2 dot cz 25-Oct-2018 02:14
This function is creating new queue (and returning true) if you set NULL into $key variable.

<?php

$isQueueCreated = msg_queue_exists(NULL);
print $isQueueCreated ? "WTF??!" : "ok, everything is fine..";

?>

WTF??!

# ipcs -q
0x00000000 173047808  root       0        0            0
tkuschel at loytec dot com 05-Jul-2012 08:40
Following code will do the job:
<?php
$key = 0;
while (true) {
  echo $key,"...\r";
  if (msg_queue_exists($key))
   echo "\r",$key,'::Exists',"\n";
   $key++;
}
?>
michael dot hajuu at gmail dot com 09-Mar-2011 05:01
A simple script for checking what message queues are in use on a [presumably new] server environment.

Run with php-cli

<?php
$k = 0;
while (true) {
  echo $key,"...\r";
  if (msg_queue_exists($key))
   echo "\r",$key,'::Exists',"\n";
   $key++;
}
?>
jaredm 10-Dec-2009 04:31
A workaround for those not yet running 5.3 on *nix:

<?php
function queue_exists($key) {
    if(function_exists("msg_queue_exists")) {
        return msg_queue_exists($key);
    } else {
        $aQueues = array();
        exec("ipcs -q | grep \"^[0-9]\" | cut -d \" \" -f 1", $aQueues);
        if(in_array($key,$aQueues)) return true;
        else return false;
    }
}
?>

Maybe a bit slow and kludgey, but it works.