s = "\naaaa\nbbbb" s.sub!(/^\n?/,"")
>> s = "\naaaa\nbbbb" #=> "\naaaa\nbbbb" >> s.lstrip #=> "aaaa\nbbbb"
从文档:
Returns a copy of str with leading whitespace removed. See also String#rstrip and String#strip.
http://ruby-doc.org/core-1.9.3/String.html#method-i-lstrip