第二个参数可以是字符列表:

the second parameter can be a charlist:

$description_new = ltrim($description_new, '#.,!?()');

如果满足您的需要，您还可以添加一系列字符:

You could also add a range of characters if it would suit your needs:

$clean = ltrim($binary, "\x00..\x1F");

阅读:function.ltrim