Lesson 1: The Linux filesystem¶

Looking at directories from within a Linux terminal can often seem confusing. But bear in mind that these directories are exactly the same type of folders that you can see if you use any graphical file browser. From the root level (/) there are usually around 20 directories. You can treat the root directory like any other, e.g. you can list its contents with ls:

[learner ~]$ ls /
bin  dev         etc  lib   lost+found mnt proc run  singularity sys usr
boot environment home lib64 media      opt root sbin srv         tmp var

Filesystem Terminal Colours¶

You might notice some of these files or directories appearing in different colours. Many Linux shells provide features which will let you display files and directories in different colours to make their purpose clear (much like a GUI would use icons). The typical colours used are as following:

file

Typical Filesystem Directories¶

Directory         Purpose
----------------- ---------------------------------------------------------------------------------------
/bin              Command binaries that need to be available for all users.
/boot             Files used during system boot, e.g., GRUB, Kernel(s) and System memory maps.
/dev              Device files such as drivers and interfaces to printers and serial ports.
/etc              System-wide configuration files only, no binaries.
/home             User's home directories, saved files, personal settings, etc.
/lib and /lib64   32-bit and 64-bit libraries essential for the binaries in /bin and /sbin.
/media            Mounting point for removable media such as CD-ROMs and Flash drives.
/mnt              Temporary mounted filesystems.
/opt              Optional application software packages.
/proc             Virtual filesystem providing process and kernel information as files.
/root             Home directory of the root user.
/run              Runtime information stored by applications and system daemons.
/sbin             Essential system binaries.
/tmp              Temporary files created by scripts or placed by users.
/usr              Read-only user data containing the majority of multi-user utilities and applications.
/var              Variable files whose content is expected to continually change.

When you log in to Linux you tend to start your session in your home directory (where personal files are traditionally saved), and this is often inside a directory called 'users' or 'home'.