is_utf8 in PHP

By: rodrigo  

I've been working on a is_utf8 function and wanted to post it here, in addition to others i also took in consideration the 5000 char bug:

<?php 
define('_is_utf8_split',5000); 

function is_utf8($string) { // v1.01 
    if (strlen($string) > _is_utf8_split) { 
        // Based on: http://mobile-website.mobi/php-utf8-vs-iso-8859-1-59 
        for ($i=0,$s=_is_utf8_split,$j=ceil(strlen($string)/_is_utf8_split);$i < $j;$i++,$s+=_is_utf8_split) { 
            if (is_utf8(substr($string,$s,_is_utf8_split))) 
                return true; 
        } 
        return false; 
    } else { 
        // From http://w3.org/International/questions/qa-forms-utf-8.html 
        return preg_match('%^(?: 
                [x09x0Ax0Dx20-x7E]            # ASCII 
            | [xC2-xDF][x80-xBF]             # non-overlong 2-byte 
            |  xE0[xA0-xBF][x80-xBF]        # excluding overlongs 
            | [xE1-xECxEExEF][x80-xBF]{2}  # straight 3-byte 
            |  xED[x80-x9F][x80-xBF]        # excluding surrogates 
            |  xF0[x90-xBF][x80-xBF]{2}     # planes 1-3 
            | [xF1-xF3][x80-xBF]{3}          # planes 4-15 
            |  xF4[x80-x8F][x80-xBF]{2}     # plane 16 
        )*$%xs', $string); 
    } 
} 
?>




Archived Comments


Most Viewed Articles (in PHP )

Installing PHP with nginx-server under windows

PHP ./configure RESULTING IN [email protected]_2_2_3_... AND UNRESOLVED REFERENCES WITH ORACLE OCI8

PHP 5.1.4 INSTALLATION on Solaris 9 (Sparc)

Building PHP 5.x with Apache2 on SuSE Professional 9.1/9.2

Installing PHP 5.x with Apache 2.x on HP UX 11i and configuring PHP 5.x with Oracle 9i

Cannot load /usr/local/apache/libexec/libphp4.so into server: ld.so.1:......

Setting up PHP in Windows 2003 Server IIS7, and WinXP 64

error: "Service Unavailable" after installing PHP to a Windows XP x64 Pro

Running different websites on different versions of PHP in Windows 2003 & IIS6 platform

Function to convert strings to strict booleans in PHP

Convert IP address to integer and back to IP address in PHP

Function to return number of digits of an integer in PHP

Function to force strict boolean values in PHP

Function to sort array by elements and count of element in PHP

PHP pages does not display in IIS 6 with Windows 2003

Latest Articles (in PHP)