Edit report at http://bugs.php.net/bug.php?id=26244&edit=1
ID: 26244
Comment by: lukas_panek at yahoo dot com
Reported by: willn at umich dot edu
Summary: regular expression order matters when it shouldn't
Status: Bogus
Type: Bug
Package: Regexps related
Operating System: Solaris 5.8
PHP Version: 4.3.2
Block user comment: N
Private report: N
New Comment:
Thank you.
Escaping the "-" character with a bakslash works also.
e.g.: preg_match('/^<!--([a-zA-Z_\-\.]*)-->/',$radka,$match)
Wouldnt have found out without this thread
L
Previous Comments:
------------------------------------------------------------------------
[2003-11-13 15:05:13] j...@php.net
The '-' character means range when it's between the
[ and ]. You need to put it as the first character or the
second character between the [^ and ], which is why $b,
$c, $d and $e work fine.
J
------------------------------------------------------------------------
[2003-11-13 14:36:47] willn at umich dot edu
Description:
------------
Within the "anti-match" square brackets, order shouldn't make a
difference, but it does. I'm writing a simple anti-injection attack
filter to pull out all the illegal characters, and leave the ones that I
want. Unfortunately, I found that with this particular combination, I've
been getting this error message:
[Thu Nov 13 14:25:41 2003] [error] PHP Warning: Compilation failed:
range out of order in character class at offset 4 in
/usr/local/projects/vote-dev/public/test.php on line 5
The code below demonstrates the simplest case I could find that would
replicate the problem. Swapping the order a little bit makes it work a
little better - as you can see that the $a and $f variables have some
issues.
Reproduce code:
---------------
<pre><?php
$text = 'This, is my - "favorite".';
$a = preg_replace( '/[^,-"]/', '', $text );
$b = preg_replace( '/[^,"-]/', '', $text );
$c = preg_replace( '/[^-,"]/', '', $text );
$d = preg_replace( '/[^-",]/', '', $text );
$e = preg_replace( '/[^",-]/', '', $text );
$f = preg_replace( '/[^"-,]/', '', $text );
echo "$text\na:$a\nb:$b\nc:$c\nd:$d\ne:$e\nf:$f";
?></pre>
Expected result:
----------------
This, is my - "favorite".
a:,-""
b:,-""
c:,-""
d:,-""
e:,-""
f:,-""
Actual result:
--------------
This, is my - "favorite".
a:
b:,-""
c:,-""
d:,-""
e:,-""
f:,""
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/bug.php?id=26244&edit=1
