ls -l {,**/}*.ext

为了使双星号glob工作，需要设置globstar选项(默认：on)：

shopt -s globstar

从人bash：

    globstar
                  If set,the pattern ** used in a filename expansion con‐
                  text will match a files and zero or more directories and
                  subdirectories.  If the pattern is followed by a /,only
                  directories and subdirectories match.