man hier

　こんなものがあるとは知らなかった。

man hier

　MacBook Airでやるとこんな感じ。

HIER(7)              BSD Miscellaneous Information Manual              HIER(7)

NAME
     hier -- layout of filesystems

DESCRIPTION
     A historical sketch of the filesystem hierarchy.  The modern OS X filesystem is documented in the ``File System Programming
     Guide'' available on Apple Developer.

     /             root directory of the filesystem

     /bin/         user utilities fundamental to both single-user and multi-user environments

     /dev/         block and character device files

                   fd/  file descriptor files; see fd(4)

     /etc/         system configuration files and scripts

     /mach_kernel  kernel executable (the operating system loaded into memory at boot time).

     /sbin/        system programs and administration utilities fundamental to both single-user and multi-user environments

　ある日、突然、気づくんだよなぁ。