Bug #75868 [Com]: is_resource() gettype() get_resources() inconsistent result on closed resource
Edit report at https://bugs.php.net/bug.php?id=75868&edit=1
ID: 75868
Comment by: spam2 at rhsoft dot net
Reported by: bobonov at gmail dot com
Summary: is_resource() gettype() get_resources() inconsistent
result on closed resource
Status: Not a bug
Type: Bug
Package: Variables related
Operating System: Ubuntu 17.10
PHP Version: 7.2.1
Assigned To: cmb
Block user comment: N
Private report: N
New Comment:
and how do you imagine is_resource() to be useful when it answers yes ona closed one which
can't be used in the next line?
changing that would be a regression and break existing code for no purpose
Previous Comments:
------------------------------------------------------------------------
[2018-01-25 15:16:39] bobonov at gmail dot com
In the title I reported it as "inconsistent result on closed resource".
I know that is the intend behavior, as clearly reported in the documentation, but anyway it is a
bug.
While 2 function report it as still a resource, is_resource() say is not a resource.
Yes gettype() report it as "resource (closed)" which in my opinion is a strange type since
closed denote a status not a variable type, or at least resource type
We have 3 different result checking the same variable
is_resource() say is a resource
gettype() report "resource (closed)" (which in php does not exist)
get_resources() which still list it as resource
To make more clear the inconsistent type checking by different function for a resource I made a bit
more complete script (in which you can see that var_dump() get_resource_type() still see closed one
as resource).
In particular get_resource_type() give a warning when used to test a non resource type.
"PHP Warning: get_resource_type() expects parameter 1 to be resource, string given"
So if even the runtime see closed resource as resource... it is a resource
<?php
function testResource($a) {
echo "$a\n";
echo "gettype(): " . gettype($a)."\n";
echo "is_resource():";
var_dump(is_resource($a));
echo "get_resource_type(): " . get_resource_type ( $a )."\n";
echo "get_resources():";
print_r(get_resources());
echo "var_dump():";
var_dump($a);
}
$a = fopen('http://www.google.com',
'r');
echo "OPEN resource\n";
testResource($a);
fclose($a);
echo "\n\n\nCLOSED resource\n";
testResource($a);
?>
this script will produce the following result:
OPEN resource
Resource id #6
gettype(): resource
is_resource():bool(true)
get_resource_type(): stream
get_resources():Array
(
[1] => Resource id #1
[2] => Resource id #2
[3] => Resource id #3
[4] => Resource id #4
[6] => Resource id #6
)
var_dump():resource(6) of type (stream)
CLOSED resource
Resource id #6
gettype(): resource (closed)
is_resource():bool(false)
get_resource_type(): Unknown
get_resources():Array
(
[1] => Resource id #1
[2] => Resource id #2
[3] => Resource id #3
[4] => Resource id #4
[6] => Resource id #6
)
var_dump():resource(6) of type (Unknown)
Probably the correct output (to make everything consistent and logic) for a closed resource should
be:
gettype(): resource
is_resource():bool(true)
get_resource_type(): closed
var_dump():resource(6) of type (closed)
All "resource provider" should change a resource type to closed when *close() is called.
------------------------------------------------------------------------
[2018-01-25 13:41:46] cmb@php.net
> Checking the closed resource with:
> is_resource() return false.
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
This is documented[1] behavior:
| is_resource() is not a strict type-checking method: it will
| return FALSE if var is a resource variable that has been closed.
[1] <http://www.php.net/manual/en/function.is-resource.php#refsect1-function.is-resource-notes>
------------------------------------------------------------------------
[2018-01-24 14:31:43] bobonov at gmail dot com
Description:
------------
Checking the closed resource with:
gettype() return resource (closed)
get_resources() list it as resource
is_resource() return false.
There is an ancient Bug #42797 (php 4.3.6) that is relevant to this bug
Test script:
---------------
<?php
$a = fopen('http://www.google.com',
'r');
echo "$a : the type is " . gettype($a)."\n"; // resource
var_dump(is_resource($a)); // true
print_r(get_resources());
fclose($a);
echo "$a : the type is " . gettype($a)."\n"; // resource closed
var_dump(is_resource($a)); // false
print_r(get_resources());
Expected result:
----------------
I expect is_resource() to return true since get_resources() and gettype() see the var as resource
Actual result:
--------------
Resource id #6 : the type is resource
bool(true)
Array
(
[1] => Resource id #1
[2] => Resource id #2
[3] => Resource id #3
[4] => Resource id #4
[6] => Resource id #6
)
Resource id #6 : the type is resource (closed)
bool(false)
Array
(
[1] => Resource id #1
[2] => Resource id #2
[3] => Resource id #3
[4] => Resource id #4
[6] => Resource id #6
)
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=75868&edit=1
Thread (7 messages)