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
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): stringThis 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
// prints: stream
$fp = fopen("foo", "w");
echo get_resource_type($fp) . "\n";
// prints: curl
$c = curl_init ();
echo get_resource_type($c) . "\n"; // works prior to PHP 8.0.0 as since 8.0 curl_init returns a CurlHandle object
?>
add a note
User Contributed Notes 1 note
CertaiN ¶
10 years ago
