How to get instance ID with PHP

Question

I'm looking for a way to get the instance ID of a given object / resource with PHP, the same way var_dump() does:

var_dump(curl_init()); // resource #1 of type curl
var_dump(curl_init()); // resource #2 of type curl

How can I get the instance count without calling var_dump()? Is it possible?

what for? it makes little sense. – just somebody Dec 05 '09 at 22:18 — just somebody, Dec 05 '09 at 22:18

score 6 · Accepted Answer · answered Dec 05 '09 at 22:24

6

Convert it to an int to get the resource ID:

$resource= curl_init();
var_dump($resource);
var_dump(intval($resource));

answered Dec 05 '09 at 22:24

leepowers

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He mentioned without using `var_dump` ;) – Jakub Dec 05 '09 at 22:26
So simple... Thanks pygorex1! – Alix Axel Dec 05 '09 at 22:26
2

This is actually a very good solution. You could also just do (int) $resource – Chris Gutierrez Dec 05 '09 at 22:27
2

or, equivalently: `(int)$resource`. But the manual says that technically this conversion is undefined. – newacct Dec 05 '09 at 22:28
You don't happen to have a solution for http://stackoverflow.com/questions/2872366/get-instance-id-of-an-object-in-php, don't you? :) – Alix Axel May 20 '10 at 10:41

score 4 · Answer 2 · edited Jan 09 '22 at 02:04

4

Before PHP 8.0:

(int) curl_init();

PHP 8.0+:

spl_object_id(curl_init());

Across versions:

$handle = curl_init();
is_object($handle) ? spl_object_id($hadle) : (int) $handle;
// unset($handle);

edited Jan 09 '22 at 02:04

hakre

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answered Dec 05 '09 at 22:23

Joscha

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because I initially thought you really need to get the exact string "resource(x) of type Y" - but after I read your question again I figured you really only want the integer value without the clutter ;-) – Joscha Dec 05 '09 at 22:34
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In php8, curl_init() no longer returns a resource, it returns an instance of CurlHandle – Simon Jul 08 '21 at 13:16

score 3 · Answer 3 · edited Jan 09 '22 at 02:06

3

This is a very interesting question... I would be interested to see what you would use this for... but here is one way...

$ch = curl_init();
preg_match("#\d+#", (string) $ch, $matches);
$resourceIdOne = end($matches);

$ch2 = curl_init();
preg_match("#\d+#", (string) $ch2, $matches);
$resourceIdTwo = end($matches);

compare: https://stackoverflow.com/a/68303184/367456

edited Jan 09 '22 at 02:06

hakre

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answered Dec 05 '09 at 22:19

Chris Gutierrez

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I won't be using this for anything out of the normal, I was thinking in replacing the var_dump() for a more informative / readable function but I suppose it can be used in a clever registry pattern as well. – Alix Axel Dec 05 '09 at 22:28

score 1 · Answer 4 · answered Apr 19 '19 at 22:11

1

Convert resource to id with sprintf()

$resource = curl_init();
$id = sprintf('%x', $resource);

// mimic var_dump();
$type = get_resource_type($resource);
echo "resource({$id}) of type ({$type})\n";

answered Apr 19 '19 at 22:11

Jonny

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score 1 · Answer 5 · answered Jul 08 '21 at 14:04

1

In PHP8 many functions return now a class instance instead of a resource:

$resource = curl_init();
$id = PHP_MAJOR_VERSION >= 8 ? spl_object_id(resource) : (int)resource;

or

$id = is_resource($resource) ? (int)resource : spl_object_id(resource);

answered Jul 08 '21 at 14:04

Simon

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score 0 · Answer 6 · answered Dec 27 '12 at 21:40

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function get_resource_id($resource) {
    if (!is_resource($resource))
        return false;

    return array_pop(explode('#', (string)$resource));
}

answered Dec 27 '12 at 21:40

silkfire

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How to get instance ID with PHP

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