From:
Operating system: ALL
PHP version: 5.3.3
Package: *Regular Expressions
Bug Type: Bug
Bug description:preg_match not matching last backslash '\'
Description:
------------
preg_match() does not match the last backslash at the end of a subject
string.
I'm using the pattern "#^[^0-9a-zA-Z]*$#" to filter out any characters from
user input other than alphanumerics.
The Problem I'm seeing is if there is a backslash \ as the last character
with valid characters before it, then preg_match() does not match it.
Example input:
\ = matched.
\\ = matched.
a\a = matched.
&@$ = matched.
a\ = not matched.
0\ = not matched.
A\ = not matched.
abc\ = not matched.
etc...
Test script:
---------------
// Obviously taking into account here that backslash \ is an escape char.
// SO double the backslash.
$userInput = "a\\";
if (preg_match("#^[^0-9a-zA-Z]*$#", $userInput))
{
echo "Invalid input";
}
else
{
echo "Good to go!";
}
// If you negate the regular expression to "#^[0-9a-zA-Z]*$#" and change
the
// test statement to be:
// if (!preg_match("#^[0-9a-zA-Z]*$#", $userInput)) {}
// it works as expected.
Expected result:
----------------
Expected result: Invalid input
Actual result:
--------------
Actual result: Good to go!
--
Edit bug report at http://bugs.php.net/bug.php?id=52788&edit=1
--
Try a snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=52788&r=trysnapshot52
Try a snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=52788&r=trysnapshot53
Try a snapshot (trunk):
http://bugs.php.net/fix.php?id=52788&r=trysnapshottrunk
Fixed in SVN:
http://bugs.php.net/fix.php?id=52788&r=fixed
Fixed in SVN and need be documented:
http://bugs.php.net/fix.php?id=52788&r=needdocs
Fixed in release:
http://bugs.php.net/fix.php?id=52788&r=alreadyfixed
Need backtrace:
http://bugs.php.net/fix.php?id=52788&r=needtrace
Need Reproduce Script:
http://bugs.php.net/fix.php?id=52788&r=needscript
Try newer version:
http://bugs.php.net/fix.php?id=52788&r=oldversion
Not developer issue:
http://bugs.php.net/fix.php?id=52788&r=support
Expected behavior:
http://bugs.php.net/fix.php?id=52788&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=52788&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=52788&r=submittedtwice
register_globals:
http://bugs.php.net/fix.php?id=52788&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=52788&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=52788&r=dst
IIS Stability:
http://bugs.php.net/fix.php?id=52788&r=isapi
Install GNU Sed:
http://bugs.php.net/fix.php?id=52788&r=gnused
Floating point limitations:
http://bugs.php.net/fix.php?id=52788&r=float
No Zend Extensions:
http://bugs.php.net/fix.php?id=52788&r=nozend
MySQL Configuration Error:
http://bugs.php.net/fix.php?id=52788&r=mysqlcfg
