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Bug #30957 filesystem functions bugs in destructor (under gc condition)
Submitted: 2004-12-02 11:01 UTC Modified: 2005-01-31 01:00 UTC
Votes:14
Avg. Score:4.7 ± 0.6
Reproduced:10 of 10 (100.0%)
Same Version:3 (30.0%)
Same OS:7 (70.0%)
From: rueycheng at gmail dot com Assigned:
Status: No Feedback Package: Class/Object related
PHP Version: 5.0.1 OS: Windows XP
Private report: No CVE-ID: None
View Developer Edit
 [2004-12-02 11:01 UTC] rueycheng at gmail dot com 
Description:
------------
Some filesystem functions, like file_put_contents() or fwrite(), don't work properly in the destructor __destruct().  The following scenario may looks a bit weird: it appeared that the file is not overwritten or even created, but PHP does 'read' the content of the imaginary file!

If you uncomment the last line of the code, everything would works fine.

Thanks.

$ diff php.ini php.ini-dist
288c288
< error_reporting  =  E_ALL
---
> error_reporting  =  E_ALL & ~E_NOTICE & ~E_STRICT
436c436
< include_path = ".;c:\php-5.0.1\PEAR"
---
> ;include_path = ".;c:\php\includes"
450c450
< extension_dir = "c:\php-5.0.1\ext"
---
> extension_dir = "./"
571,573c571,573
< extension=php_mbstring.dll
< extension=php_mcrypt.dll
< extension=php_mhash.dll
---
> ;extension=php_mbstring.dll
> ;extension=php_mcrypt.dll
> ;extension=php_mhash.dll
578c578
< extension=php_mysql.dll
---
> ;extension=php_mysql.dll

Reproduce code:
---------------
<?
class Bug
{
	private $filename;
	
	public function __construct($filename) {
		$this->filename = $filename;
	}
	
	public function __destruct() {
		echo "[";
		file_put_contents($this->filename, 'Gotcha!');
		echo file_get_contents($this->filename);
		echo "]";
	}
}

$bug = new Bug('.bugtest');
//unset($bug);
?>

Expected result:
----------------
[Gotcha!]

(And the file .bugtest under working directory should be created.)

$ cat .bugtest
Gotcha!

Actual result:
--------------
[Gotcha!]

$ cat .bugtest
cat: .bugtest: No such file or directory

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2004-12-02 11:25 UTC] rueycheng at gmail dot com 
The garbage collector may clean up the object prior to its __destruct() invocation.  Nothing would go wrong if you explicitly *destroy* the object.

By the way, I tested the code on Redhat 7.3 with the following configuration.  

$ cat config.nice
#! /bin/sh
#
# Created by configure

'./configure' \
'--with-apxs=/usr/local/apache/bin/apxs' \
'--with-mysql=/usr/local/mysql/' \
'--with-libxml-dir' \
'--enable-dba' \
'--enable-mbstring' \
"$@"

$ diff php.ini ../src/php-5.0.1/php.ini-recommended
353c353
< display_errors = On
---
> display_errors = Off
407c407
< ;error_log = /var/log/php.log
---
> ;error_log = filename
491c491
< include_path = ".:/usr/local/lib/php"
---
> ;include_path = ".:/php/includes"


As a result, two warnings are generated.

[
Warning: file_put_contents(./.bugtest) [function.file-put-contents]: failed to open stream: Permission denied in /home/httpd/html/testbed/bugtest.php on line 12

Warning: file_get_contents(./.bugtest) [function.file-get-contents]: failed to open stream: No such file or directory in /home/httpd/html/testbed/bugtest.php on line 13
]

Actually I've already enabled the write-permission for the directory.  The execution of these filesystem functions outside of __destruct() is OK.
 [2004-12-13 03:09 UTC] iquito at gmx dot ch 
I also encountered this bug, it is very annoying - a class of mine checks a file with a simple file_exists(), and the file isn't found - the whole script works if I call the destructor at the very end of it explicitly (which isn't really the point of having a destructor). it seems no file functions work at all in the destructor. This bug also applies to register_shutdown_function, it just seems that as soon as the "regular" scripts stops, everything that comes after that has problems with the file system.
 [2005-01-12 02:03 UTC] tony2001@php.net 
Please try using this CVS snapshot:

  http://snaps.php.net/php5-STABLE-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php5.0-win32-latest.zip

Can't reproduce under Linux. 
Please, try the snapshot.
 [2005-01-31 01:00 UTC] php-bugs at lists dot php dot net 
No feedback was provided for this bug for over a week, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
 
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