get_resource_type

(PHP 4 >= 4.0.2, PHP 5, PHP 7, PHP 8)

get_resource_type — Returns the resource type

Description

get_resource_type(resource $resource): string

This function gets the type of the given resource.

Parameters

resource: The evaluated resource handle.

Return Values

If the given resource is a resource, this function will return a string representing its type. If the type is not identified by this function, the return value will be the string Unknown.

This function will return null and generate an error if resource is not a resource.

Examples

Example #1 get_resource_type() example

<?php
$fp = fopen("foo", "w");
echo get_resource_type($fp) . "\n";

// As of PHP 8.0.0, the following does not work anymore. The curl_init function returns a CurlHandle object now.
$c = curl_init();
echo get_resource_type($c) . "\n";
?>

Output of the above example in PHP 7:

stream
curl

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User Contributed Notes 1 note

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CertaiN ¶

10 years ago

Try this to know behavior:

<?php
function resource_test($resource, $name) {
    echo 
        '[' . $name. ']',
        PHP_EOL,
        '(bool)$resource => ',
        $resource ? 'TRUE' : 'FALSE',
        PHP_EOL,
        'get_resource_type($resource) => ',
        get_resource_type($resource) ?: 'FALSE',
        PHP_EOL,
        'is_resoruce($resource) => ',
        is_resource($resource) ? 'TRUE' : 'FALSE',
        PHP_EOL,
        PHP_EOL
    ;
}
 
$resource = tmpfile();
resource_test($resource, 'Check Valid Resource');
 
fclose($resource);
resource_test($resource, 'Check Released Resource');
 
$resource = null;
resource_test($resource, 'Check NULL');
?>

It will be shown as...

[Check Valid Resource]
(bool)$resource => TRUE
get_resource_type($resource) => stream
is_resoruce($resource) => TRUE

[Check Released Resource]
(bool)$resource => TRUE
get_resource_type($resource) => Unknown
is_resoruce($resource) => FALSE

[Check NULL]
(bool)$resource => FALSE
get_resource_type($resource) => FALSE
Warning:  get_resource_type() expects parameter 1 to be resource, null given in ... on line 10
is_resoruce($resource) => FALSE