ID: 41430
User updated by: nikhil dot gupta at in dot ibm dot com
Reported By: nikhil dot gupta at in dot ibm dot com
Status: Closed
Bug Type: Filesystem function related
Operating System: LINUX, Win32-xp
PHP Version: 5CVS-2007-05-18 (snap)
New Comment:
I mean the following:
Testcase:
<?php
file_put_contents("data.txt", "abcdef");
var_dump( file_get_contents("data.txt", FALSE, NULL, -2) );
?>
Actual Output:
string(6) "abcdef"
I was asking whether negative values for offset is acceptable?
I was suggesting to handle the negative offset values with a warning
message similar to maxlen rather than output similar to that of
offset=0.
Previous Comments:
------------------------------------------------------------------------
[2007-05-21 09:01:20] [EMAIL PROTECTED]
>I think for negative values (<=-1) of offset parameter also , the
>warning message like "offset must be greater than or equal to zero"
>should be displayed.
It is displayed for all values < 0 (when the parameter is specified).
------------------------------------------------------------------------
[2007-05-21 07:16:35] nikhil dot gupta at in dot ibm dot com
Thanks for the fix!
Now I see that for maxlen=-1 also, the warning message is displayed
(earlier it behaved same as maxlen=0 without warning message) which
according to me is perfectly fine now.
But same question arises for offset parameter values handling also.
When offset value is <=-1, it behaves same as offset=0 and there is no
warning message displayed for offset to be greater than or equal to zero
as displayed for maxlen after the fix for this bug.
I think for negative values (<=-1) of offset parameter also , the
warning message like :
"offset must be greater than or equal to zero" should be displayed.
------------------------------------------------------------------------
[2007-05-18 12:07:01] [EMAIL PROTECTED]
This bug has been fixed in CVS.
Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
Thank you for the report, and for helping us make PHP better.
------------------------------------------------------------------------
[2007-05-18 11:30:04] nikhil dot gupta at in dot ibm dot com
Description:
------------
Fatal error is generated when the parameter "maxlen" of
file_get_contents() is provided with value < -1. This behaviour is on
PHP5 as well as on PHP6 on win32-xp and Linux.
Suggested Fix:
file : ext/standard/file.c
function: file_get_content()
Code : This code snipped should be added just after parsing the
input parameters.
if ( maxlen < -1) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Maxlen parameter
must be greater than or equal to 0");
RETURN_FALSE;
}
Explanation for the warning message in the suggested fix:
The maxlen is being checked for < -1 and not < 0 because, maxlen is
initialized to PHP_STREAM_COPY_ALL (i.e -1 ). The -1 mean that entire
file will be read. default value -1 of maxlen is not documented in the
php doc ,so user getting the warning message saying "Maxlen parameter
must be greater than or equal to 0" is valid.
Reproduce code:
---------------
<?php
file_put_contents("datafile.txt", "abcdef");
var_dump(file_get_contents("datafile.txt", FALSE, NULL, 0, -1) );
var_dump(file_get_contents("datafile.txt", FALSE, NULL, 0, -5) );
?>
Expected result:
----------------
FATAL error is not expected. The negative value of maxlen should be
handled with proper warning message.
Actual result:
--------------
string(6) "abcdef"
PHP Fatal error: Out of memory (allocated 262144) (tried to allocate
-4 bytes)
in C:\My_PROJECTS\PHP\workdir\binaries\php5\latest\tmp.php on line 4
BACKTRACE:
(gdb) bt
#0 zend_mm_safe_error (heap=0x83ec1e8, format=0x83b751c "Out of memory
(allocated %ld) at %s:%d (tried to allocate %ld bytes)",
limit=262144,filename=0x83a2a48
"/home/nikhil/workdir/php5/php5.2-200705150430/main/streams/streams.c",
lineno=1234, size=4294967292)
at /home/nikhil/workdir/php5/php5.2-20705150430/Zend/zend_alloc.c:1616
#1 0x0828895e in _zend_mm_alloc_int (heap=0x83ec1e8,size=4294967292,
__zend_filename=0x83a2a48
"/home/nikhil/workdir/php5/php5.2-200705150430/main/streams/streams.c",
__zend_lineno=1234,
__zend_orig_filename=0x838f1c4
"/home/nikhil/workdir/php5/php5.2-200705150430/ext/standard/file.c",
__zend_orig_lineno=555)
at
/home/nikhil/workdir/php5/php5.2-200705150430/Zend/zend_alloc.c:1815
#2 0x082899b2 in _emalloc (size=4294967292, __zend_filename=0x83a2a48
"/home/nikhil/workdir/php5/php5.2-200705150430/main/streams/streams.c",
__zend_lineno=1234, __zend_orig_filename=0x838f1c4
"/home/nikhil/workdir/php5/php5.2-200705150430/ext/standard/file.c",
__zend_orig_lineno=555)at
/home/nikhil/workdir/php5/php5.2-200705150430/Zend/zend_alloc.c:2243
#3 0x0826df2b in _php_stream_copy_to_mem (src=0xb7fb30f0,
buf=0xbfffd188, maxlen=4294967291, persistent=0,
__php_stream_call_depth=0,
__zend_filename=0x838f1c4
"/home/nikhil/workdir/php5/php5.2-200705150430/ext/standard/file.c",
__zend_lineno=555, __zend_orig_filename=0x0,
__zend_orig_lineno=0) at
/home/nikhil/workdir/php5/php5.2-200705150430/main/streams/streams.c:1234
#4 0x081f1daf in zif_file_get_contents (ht=5, return_value=0xb7fb2b94,
return_value_ptr=0x0, this_ptr=0x0, return_value_used=1)
at
/home/nikhil/workdir/php5/php5.2-200705150430/ext/standard/file.c:555
#5 0x082c2ae1 in zend_do_fcall_common_helper_SPEC
(execute_data=0xbfffd380) at
/home/nikhil/workdir/php5/php5.2-200705150430/Zend/zend_vm_execute.h:200
#6 0x082c753a in ZEND_DO_FCALL_SPEC_CONST_HANDLER
(execute_data=0xbfffd380) at
/home/nikhil/workdir/php5/php5.2-200705150430/Zend/zend_vm_execute.h:1681
#7 0x082c26f6 in execute (op_array=0xb7fb1c88) at
/home/nikhil/workdir/php5/php5.2-200705150430/Zend/zend_vm_execute.h:92
#8 0x082a31f2 in zend_execute_scripts (type=8, retval=0x0,
file_count=3) at
/home/nikhil/workdir/php5/php5.2-200705150430/Zend/zend.c:1134
#9 0x0825bbd9 in php_execute_script (primary_file=0xbffff740) at
/home/nikhil/workdir/php5/php5.2-200705150430/main/main.c:1794
#10 0x08308ef9 in main (argc=2, argv=0xbffff814) at
/home/nikhil/workdir/php5/php5.2-200705150430/sapi/cli/php_cli.c:1138
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=41430&edit=1
