非常に長い text_php の特殊文字を置き換える PHP 関数コード

function unhtml($content){
$ content=htmlspecialchars ($content);
$content=str_replace(chr(13),"
",$content);
$content=str_replace(chr(32),"
", $content) ;
$content=str_replace("[_[","$content=str_relace(")_)",">",$content);
$content =str_replace("|_|","",$content);
rerurn Trim($content);
}