Edit report at https://bugs.php.net/bug.php?id=49874&edit=1
ID: 49874
Updated by: yohg...@php.net
Reported by: jketterl at chipxonio dot de
Summary: ftell() and fseek() inconsistency when using stream
filters
Status: Open
Type: Bug
Package: Filesystem function related
Operating System: linux (ubuntu)
-PHP Version: 5.2.11
+PHP Version: 5.5.4
Block user comment: N
Private report: N
New Comment:
It seems 5.5 has this problem still
string(8) "Line 01
"
string(8) "Line 02
"
string(8) "Line 01
"
string(5) "e 01
"
[yohgaki@dev php-5.4]$ php -v
PHP 5.5.4 (cli) (built: Sep 19 2013 13:06:40)
Previous Comments:
------------------------------------------------------------------------
[2009-10-15 06:54:31] jketterl at chipxonio dot de
thanks for having a look
i tried with and without. the challenge is to get it working without, because
that's the worst case my app has to deal with, but the BOM doesn't seem to
solve this.
$ hexdump test-with-bom.csv
0000000 feff 004c 0069 006e 0065 0020 0030 0031
0000010 000a 004c 0069 006e 0065 0020 0030 0032
0000020 000a 004c 0069 006e 0065 0020 0030 0033
0000030 000a 004c 0069 006e 0065 0020 0030 0034
0000040 000a
0000042
$ php test.php
string(8) "Line 01
"
string(8) "Line 02
"
string(8) "Line 01
"
string(5) "e 01
"
i also tried opening the file including the BOM without a stream filter, but
that just resulted in php reading in two extra chars (the BOM converted in some
way i guess) on the beginning of the first line.
i thought i'd attach the sample files to this bug, but it seems like i can't.
i've uploaded them here instead: http://www.djmacgyver.net/tmp/php-ftell/
------------------------------------------------------------------------
[2009-10-14 16:40:00] sjo...@php.net
Thank you for your bug report. Does your test.csv file start with a BOM? You
can determine this by viewing the file in a hex editor. If it starts with fffe
or feff, it has a BOM (byte order mark).
------------------------------------------------------------------------
[2009-10-14 11:39:39] jketterl at chipxonio dot de
Description:
------------
exact php version: PHP 5.2.11-0.dotdeb.1 with Suhosin-Patch 0.9.7 (cli) (built:
Sep 20 2009 09:41:43)
this bug is also be filter-/stream-related. i just believe it might be easier
to fix on the filesystem side, that's why i chose that category.
when using a php stream filter to convert input from utf-16 into iso8859 (or
most probably from any 2byte-encoded charset into any single-byte-encode
charset) the ftell() and fseek() functions start to behave inconsistently.
more precisely: fseek() jumps to exact offsets ignoring the 2byte-encoding,
whereas ftell() seems to return the number of bytes read *after* the filter has
been applied. thus it is not possible to fseek() back to a certain offset that
has been stored with ftell() before.
the content of the testfile used in the code examples is as follows:
Line 01
Line 02
Line 03
Line 04
Reproduce code:
---------------
$file = 'test.csv';
$fp = fopen($file, 'r');
stream_filter_append($fp, 'convert.iconv.utf16/iso8859-15');
$line = fgets($fp);
var_dump($line);
$line = fgets($fp);
var_dump($line);
fclose($fp);
$fp = fopen($file, 'r');
stream_filter_append($fp, 'convert.iconv.utf16/iso8859-15');
$line = fgets($fp);
var_dump($line);
fseek($fp, ftell($fp)); // this shouldn't move anything - but it does...
$line = fgets($fp);
var_dump($line);
fclose($fp);
Expected result:
----------------
string(8) "Line 01
"
string(8) "Line 02
"
string(8) "Line 01
"
string(8) "Line 02
"
Actual result:
--------------
string(8) "Line 01
"
string(8) "Line 02
"
string(8) "Line 01
"
string(4) " 01
"
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=49874&edit=1
