<?php
    function mb_strrev($str){
preg_match_all('/./us',$str,$arr);
return implode(array_reverse($arr[0]));
}
function cutTweet($tweet){
if(mb_strlen($tweet)<=140){return $tweet};
$rev_pattern = "/^[A-Za-z0-9_]@/us";
$rev_str = self::mb_strrev(mb_substr($tweet,0,140));
while(true){
if(mb_strlen($rev_str)<=140) {return self::mb_strrev($rev_str)};
$rev_str = preg_replace($rev_pattern,"",$rev_str,1);
}
}
$text = "111112222233333444445555566666777778888899999000001111122222333334444455555666667777788888999990000011111222223333344444555556666677777 @ta_ka_na_m 9999900000";
$t = cutTweet($text);
echo $t;
?>

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