PHP获取表单textarea数据中的换行问题_PHP教程

$content=empty($_POST['content'])?null:trim($_POST['content']);
if(!empty($content))echo str_replace("\r",'rl',nl2br($content));
echo "\r".'
----------分割线----------------------'."\r";
if(!empty($content))echo str_replace("\n",'nl',nl2br($content));
echo "\n".'
----------分割线----------------------'."\n";
if(!empty($content))echo str_replace("\r",'rl',str_replace("\n",'nl',nl2br($content)));
echo "\r".'
----------分割线----------------------
'."\n";
echo 'hello'."\n".'boys!';
echo 'hello'."\r".'boys!';
?>