CODEWITHSUNDEEP
phpwordpressstrlen
Vasiliy
Vasiliy

Reputation: 81

PHP: strlen returns character length instead of byte length

I have a wordpress web site.

I've created simple page template like:

<?php 
 /**
 * Template Name: Test
 */

 echo strlen('Привет');

 ?>

Then i've created a page using this template. The page shows the length of russian string 'Привет' (means 'Hello'). I expect to see 12, as UTF-8 encoded russian string consisting of 6 characters should have a size of 12 bytes, but i get 6 instead.

I've tested the same thing on other server and had correct value - 12. So i think the reason is my server configuration. I have wp 3.2.1 (i had the same problem after upgrading to wp 3.5.1) and PHP 5.3.3.

Currently i've spent about 5 days trying to find a solution, but have no luck. Does anyone know what is the reason of such behavior?

Upvotes: 8

Views: 2640

Answers (5)

user2819304
user2819304

Reputation: 143

My file was set to "UCS-2 BE BOM" encoding. (can be viewed from notepad++ - Encoding menu option)

I have then used mb_strlen($line,"UCS-2") function however for some reason, I was getting incorrect string length (e.g. mb_strlen("somestr","UCS-2") -> 6, where I was expecting 7)

I have changed the encoding to "UTF-8" for the file and was able to get the correct string length.

I am not sure why I was getting incorrect string length with the other encoding type, but wanted to share what worked for me.

Upvotes: 0

Mark Baker
Mark Baker

Reputation: 212412

Check the mbstring.func_overload setting in php.ini. This option allows PHP to override the strlen() function with mb_strlen() (and similarly for other equivalents). This could explain the discrepancy between your servers

EDIT

Quoting from the doc link:

To use function overloading, set mbstring.func_overload in php.ini to a positive value that represents a combination of bitmasks specifying the categories of functions to be overloaded. It should be set to 1 to overload the mail() function. 2 for string functions, 4 for regular expression functions. For example, if it is set to 7, mail, strings and regular expression functions will be overloaded.

So a value with the 2 bit set means that basic string functions will be overloaded with their mbstring equivalent, but not mail or regular expression functions; if you want normal behaviour, this should be 0

Upvotes: 7

Bud Damyanov
Bud Damyanov

Reputation: 31829

See http://php.net/manual/en/function.mb-strlen.php for more info about getting string length in multi-byte characters.

Upvotes: 0

gratz
gratz

Reputation: 1616

Do you need to use multi-byte string functions for this? Such as http://www.php.net/manual/en/function.mb-strlen.php

Upvotes: 0

ka_lin
ka_lin

Reputation: 9432

Have you tried: http://lt.php.net/manual/en/function.mb-strlen.php ?

int mb_strlen ( string $str [, string $encoding ] )
Gets the length of a string.

Upvotes: 3

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