[Day 1] 5. Linux File Structure

!5. Linux File Structure.png

Linux File Structure

In Linux, the file system follows a tree-like structure starting from the root directory, denoted by

/

Key Directories in Linux

1. /boot directory:

   • Contains booting information.
   • The Linux kernel and initial RAM disk are stored here.

2. /bin directory:

   • Stores essential binary files (executables).
   • Contains basic command executables like
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     ls

     ,
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     cat

     , etc.

3. /sbin directory:

   • Contains binaries that only the superuser (root) can execute.
   • "S" stands for super (root user).

4. /etc directory:

   • Holds configuration files for the system.
   • Contains settings for the hostname, users, networks, etc.

5. /root directory:

   • Home directory for the root user.

6. /home directory:

   • Contains home directories for users other than the root user.
   • For example, directories for users like "ditiss" and "sunbeam" are stored here, with appropriate permissions.

7. /media directory:

   • Stores information about removable devices (e.g., pen drives, external hard disks).

8. /mnt directory:

   • Used for manually mounting removable devices.
   • A sub-directory of
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     /media

     .

9. /tmp directory:

   • Stores temporary files. These files are deleted automatically when the system is turned off.

10. /var directory:

    • Stores variable data files.
    • For example, log files, such as
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      /var/log/messages

      , where the kernel logs system messages.

11. /usr directory:

    • Stores user application data.
    • Sub-directories include:
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        bin

        : User binaries.
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        sbin

        : System binaries for administrative tasks.
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        lib

        : System libraries.
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        share

        : Documentation and shared resources for applications.

12. /lib directory:

    • Contains system libraries used by executables in
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      /bin

      and
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      /sbin

      .

13. /opt directory:

    • Stores data for third-party applications installed outside the default package management.

14. /dev directory:

    • Stores device files. In Linux, even hardware devices (e.g., pen drives, printers) are treated as files.

15. /proc directory:

    • Contains information about all running processes and system information.
    • This directory provides a virtual file system interface to kernel data structures.

16. /sys directory:

    • Contains kernel module information and details about device drivers.

Special Directories

• /dev, /proc, and /sys:
  • These directories exist only in RAM and are created dynamically during boot.
  • They are known as virtual directories or virtual file systems because they are not stored on the hard disk.

Path:

A path in Linux represents a file or directory’s unique location. Paths are separated by

/

Types of Paths

1. Absolute Path:

   • Always starts from the root (
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     /

     ).
   • Example:
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     /home/ditiss/python/demos/demo01.py

     .

2. Relative Path:

   • Starts from the current working directory.
   • Example: If you’re already in
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     /home/ditiss

     , the relative path would be
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     python/demos/demo01.py

     .