转载地址： http://blog.qita.in/?post=418 function is_utf8($string){ return preg_match('%^(?: [\x09\x0a\x0d\x20-\x7e] # ascii | [\xc2-\xdf][\x80-\xbf] # non-overlong 2-byte | \xe0[\xa0-\xbf][\x80-\xbf] # excluding overlongs | [\xe1-\xec\xee\xef][\x80-\xbf]{2} # straight 3-byte | \xed[\x80-\x9f][\x80-\xbf] # excluding surrogates | \xf0[\x90-\xbf][\x80-\xbf]{2} # planes 1-3 | [\xf1-\xf3][\x80-\xbf]{3} # planes 4-15 | \xf4[\x80-\x8f][\x80-\xbf]{2} # plane 16 )*$%xs', $string);}
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