Learning The Linux File System 2025

Video Description

This video will show you what's in all those directories in your Linux Machine, NOTE: I couldn't post all of the notes for this vid here... I have posted what I think is the most important info. Linux Filesystem Basics "Path" A path points to a file system location by following the directory tree hierarchy. Example: /home/joe/Documents/letter_to_cindy.txt "Permissions" File attributes that define who can access or change a file and whether a file can be executed as a program. "-rwxr-xr-x" Shows file type and permissions. +-------------+------+-------+ | d--------- | File Type | +-------------+------+-------+ | - = regular file | | d = directory | | l = link | +-------------+------+-------+ | Permission | Octal| Field | +-------------+------+-------+ | -rwx------ | 700 | User | | ----rwx--- | 070 | Group | | -------rwx | 007 | Other | +-------------+------+-------+ Octal values: Read = 4 Write = 2 Execute = 1 You can set permissions in the file manager or with the commend "chmod." Examples: Set a file to be executable and readable by by everyone but only writable by you: 'chmod 755 filemane' Set execute bit without changing other permisions: 'chomd +x filename' When applying permissions to directories on Linux, the permission bits have different meanings than on regular files. The write bit allows the affected user to create, rename, or delete files within the directory, and modify the directory's attributes. The read bit allows the affected user to list the files within the directory. The execute bit allows the affected user to enter the directory and access files and directories inside. "Root" Can refer to the base of a filesystem ("/") or a user with administrator privileges for a Unix/Linux computer. "Tree" A way to visualize filesystem structure. Dir ├── Dir │ ├── File │ ├── File │ └── Dir │ └── File ├── File └── File Here's an explanation of some key directories: / (Root Directory): The top-level directory in the Linux file system hierarchy. All other directories and files are located within this directory or its subdirectories. /bin (Binaries): Contains essential user command binaries that are available to all users, such as ls, cp, mv, and cat. /boot: Contains files required to boot the Linux system, including the kernel and boot loader configuration files. /dev (Devices): Contains device files, which represent hardware devices and pseudo-devices (like /dev/random for random numbers or /dev/null for discarding output). /etc (Et Cetera): Stores system-wide configuration files for various services, applications, and the operating system itself. Examples include network settings and user authentication configurations. /home: Contains individual user home directories. Each user typically has a subdirectory within /home (e.g., /home/username) for their personal files and user-specific configurations. /lib (Libraries): Holds essential shared libraries required by the binaries in /bin and /sbin. /media: A mount point for removable media devices like USB drives and CDs/DVDs. /mnt (Mount): Another mount point for temporarily mounting file systems, often used for network file systems or other temporary mounts. /opt (Optional): Used for installing optional or third-party software that is not part of the standard system distribution. /proc (Processes): A virtual file system that provides information about running processes and kernel parameters. It's dynamically generated and doesn't store files on disk. /root: The home directory for the root user (the superuser with administrative privileges). /run: Contains volatile runtime data, such as process IDs (PIDs) and sockets. This directory is typically cleared on reboot. /sbin (System Binaries): Contains essential system administration binaries, typically used by the root user for system maintenance tasks (e.g., fdisk, reboot). /srv (Services): Stores data for services provided by the system, such as web server content or FTP server data. /sys (System): A virtual file system providing an interface to kernel data structures and device information, allowing inspection and control of system behavior. /tmp (Temporary): A directory for temporary files created by applications or users. Its contents are typically cleared on system reboot. /usr (Unix System Resources): Contains a large portion of the operating system's files, including user programs, libraries, documentation, and header files. It's further organized into subdirectories like /usr/bin, /usr/lib, /usr/share, and /usr/local. /var (Variable): Stores variable data that changes frequently during system operation, such as log files (/var/log), mail queues (/var/spool/mail), and temporary files for web servers (/var/www). Leann more about the Ext file system: https://youtu.be/B6kg2zeJ9do