File Hierarchy Standard

• Linux File System uses the File Hierarchy Standard (FHS) structure
• Linux File System examples: EXT3, EXT4, XFS

File attributes

• d: Directory
• l: Link
• -: File
• c: Special file / Device file (cpu, keyboard, memory ... )
• s: socket (ex: /dev/sda)
• p: Named pipe
• b: Block device

Directories

• /boot: Boot loader and memory test. grub.cfg, linux kernel, etc
• /dev: Devices (external devices connected to pc)
• /etc: Configuration files
• /home: Personal and configuration files related to one user
• /media: Mounting point for CD rooms and other external devices
• /mnt: Mount point for everything else
• /opt: Optional add-on apps. E.g., google chrome
• /proc: Info about running processes (virtual directory). Each folder represents a PID. It's emptied on shutdown
• /root: Root user home dir
• /run: Info about the current system state and system daemons in early stages (ex: systemd, udev) (virtual directory)
• /srv: Services. Designed to be accessible to other users (e.g., httpd public files)
• /sys: Firmwares (virtual directory)
• /tmp: Temporary files. Dummy files
• /usr: Useful files and programs for the user
• /bin: User binaries (commands).
• /lib: C libraries required by executable in /bin or /sbin (Multi-architecture).
• /sbin: System binaries. Can only be run by root user. Ex: useradd.
• /local: Programs installed by source code manually
• /var: System logs, backups, cache