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Bug #3933 strpos doesn't find needle under certain conditions
Submitted: 2000-03-27 00:27 UTC Modified: 2000-03-27 01:29 UTC
From: wayne at pruvodce dot cz Assigned:
Status: Closed Package: Misbehaving function
PHP Version: 3.0.15 OS: Linux
Private report: No CVE-ID: None
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 [2000-03-27 00:27 UTC] wayne at pruvodce dot cz 
<?
if(strpos("bleble","ble",0)==false) echo("strpos has a bug!(1)\n");
if(strpos("bleble","ble",-1)==false) echo("strpos has a bug!(2)\n");
if(strpos("bleble","ble")==false) echo("strpos has a bug!(3)\n");
if(strpos("blebla","ble")==false) echo("strpos has a bug!(4)\n");
if(strpos("blable","ble")!=false) echo("now it works, weird ...\n");
if(strpos("xbleble","ble",0)!=false) echo("now it works, weird ...\n");
?>

(My friend found a bug in my template engine ... i'm pretty sure that this is the problem)

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 [2000-03-27 01:17 UTC] rasmus at cvs dot php dot net 
This is not a bug.  strpos("bleble","ble") returns position 0 as it should.
The way you are doing your check is incorrect.  The condition 0 == false is true.  You want to check for an empty string here "" to check to see if the string was not found.  A 0 return is a match.  Please see the user notes in the online manual.
http://www.php.net/manual/function.strpos.php3
 [2000-03-27 01:24 UTC] wayne at pruvodce dot cz 
OK, but manual says:
If needle is not found, returns false.
My check is correct (according to documentation).
I think it's better to return "-1" when needle isn't found.
 [2000-03-27 01:29 UTC] rasmus at cvs dot php dot net 
It does return false when the needle is not found.  However 0 and false are
ambiguous and as such your check is wrong.  There is nothing incorrect in the manual, however it could be a bit clearer.
This is also one of the reasons the === operator was introduced in PHP 4.
 
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