全角转半角

comma.php

<?php   
$str = "０１２３ＡＢＣＤＦＷＳ＼＂，．？＜＞｛｝［］＊＆＾％＃＠！～（）＋－｜：；";   
echo "$str";   
echo "<br />";   
$str = preg_replace('/\xa3([\xa1-\xfe])/e', 'chr(ord(\1)-0x80)', $str);   
echo $str;