File system

Special filenames

Some filenames have special meaning:

name meaning
. The current directory.
.. The parent directory of any given directory.
/ The root directory.
(It’s \ on Windows).
By no coincidence, this is also the path separator.

Unix only

name meaning
Filenames beginning with . are hidden files and will not normally be displayed when you ask for a directory listing.
~ Your home directory.
This is usually the current directory when you first log in.
~olivia User olivia’s home directory (you won’t necessarily have permission to look inside it).

Most Unix systems have conventions for the name of system directories too. A few of them are described below. It’s a good idea to become familiar with these so you can find your way about. Remember these are only conventions, so individual systems can — and will — do things differently:

name use
/bin Binary files — files that contain the instructions the machine follows for implementing commands or programs.
/home Often the directory containing all the users’ home directories.
/sbin System binaries, like /bin but with executables critical for system operation.
/tmp Temporary files
/usr “User” files — generally more for the users than the system.
/var “Variable” files — files expected to change a lot.
/var/log System log files.
/var/tmp Temporary files.