http://www.tec-q.com/note/2007/11/_chmod.html
http://technique.sonots.com/index.php?UNIX%2F%E3%82%B3%E3%83%9E%E3%83%B3%E3%83%89%2F%E3%83%95%E3%82%A1%E3%82%A4%E3%83%AB%E7%AE%A1%E7%90%86%2Fchmod
$ find . -type f -print | xargs chmod 644
$ find . -type d -print | xargs chmod 755
めも