Siksha Sarovar

Siksha Sarovar (sikshasarovar.com) is a free educational web application that helps students in India learn programming and prepare for academic and competitive exams. The platform offers structured coding courses (C, C++, Python, Java, HTML, CSS, PHP, Power BI, AI, Machine Learning, Data Science), complete university curriculum notes for BCA/MCA students with previous year question papers, Class 10 and Class 12 CBSE/HBSE school notes, and dedicated preparation material for SSC, UPSC, Banking, Railway and other government exams. Browsing the site is completely free and requires no account. Users may optionally sign in with Google solely to save their learning progress, quiz scores and personal preferences across devices.

Privacy Policy | Terms of Service | Contact Siksha Sarovar | About Siksha Sarovar

v4.0.9 · PWA
Siksha Sarovar logo
Siksha Sarovar
Your Learning Universe

Siksha Sarovar is a free e-learning platform for coding courses, BCA university notes and competitive exam preparation. Optional Google sign-in saves your learning progress across devices.

Initializing knowledge base…
Compiling modules 0%

Linux Architecture & Directory Structure

Lesson 4 of 31 in the free Operating System & Linux Programming notes on Siksha Sarovar, written by Rohit Jangra.

Linux at a Glance

Linux is a Unix-like, free, open-source kernel created by Linus Torvalds in 1991. Combined with GNU userland tools it forms a complete operating system.

Layers

  1. Hardware — CPU, memory, disks, NIC.
  2. Kernel — monolithic but modular. Subsystems: process scheduler, memory manager, VFS, network stack, drivers.
  3. System Call Interface (SCI) — the boundary between user space and kernel space. Examples: open, read, fork, execve.
  4. Shell & Librariesbash, zsh, glibc. The shell is just another user program that interprets commands.
  5. User Applications — editors, compilers, browsers.

Linux Filesystem Hierarchy Standard (FHS)

Everything starts from the root /.

Important Directories

PathPurpose
/binEssential commands (ls, cp, bash) needed in single-user mode.
/sbinSystem administration commands (fdisk, shutdown).
/etcPlain-text configuration files (/etc/passwd, /etc/fstab).
/homePer-user home directories.
/varVariable data: logs (/var/log), spools, caches.
/usrRead-only user-installed programs and shared data.
/devDevice nodes — disks, terminals, null.
/procVirtual filesystem exposing kernel and process state.
/sysModern interface to kernel objects (sysfs).
/tmpTemporary files cleared on reboot.
/bootKernel images and bootloader.

Everything is a File

Linux treats hardware (/dev/sda), kernel state (/proc/cpuinfo), pipes and sockets as files. This unification means tools like cat work uniformly:

Summary

  • Linux is a layered OS with a monolithic but modular kernel.
  • Standard FHS gives every distro a predictable directory tree.
  • The "everything is a file" principle simplifies the programming model.