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)
get_resource_type — Returns the resource type
Опис
string get_resource_type
( resource
$handle
)This function gets the type of the given resource.
Параметри
-
handle -
The evaluated resource handle.
Значення, що повертаються
If the given handle 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 FALSE and generate an error if
handle is not a resource.
Приклади
Приклад #1 get_resource_type() example
<?php
// prints: mysql link
$c = mysql_connect();
echo get_resource_type($c) . "\n";
// prints: stream
$fp = fopen("foo", "w");
echo get_resource_type($fp) . "\n";
// prints: domxml document
$doc = new_xmldoc("1.0");
echo get_resource_type($doc->doc) . "\n";
?>
add a note
User Contributed Notes 1 note
CertaiN ¶
10 years ago
