Master Linux Basics: Choosing Distributions, Architecture, and Core Commands

System Selection

Linux distributions fall into two main groups: commercially maintained (e.g., Red Hat Enterprise Linux, Fedora, CentOS) and community‑maintained (e.g., Debian). Ubuntu is built on Debian and combines its strengths with additional enhancements, making it a popular desktop choice. For a stable server, CentOS is recommended, while Ubuntu is often preferred for cloud environments and projects like Hadoop.

Architecture

Understanding Linux architecture gives a clear direction for learning. Linux consists of kernel and user space, with the kernel handling memory management, process management, device drivers, filesystems, and networking. The overall OS structure includes the kernel, shell, and filesystem hierarchy.

Linux Kernel

The kernel divides memory into manageable pages (e.g., 4 KB slabs) and provides abstractions such as the slab allocator. Processes are execution instances of applications; the scheduler controls CPU access. Inter‑process communication mechanisms include signals, pipes, shared memory, semaphores, and sockets. The kernel API supports creating (fork, exec), terminating (kill, exit), and synchronizing processes.

Linux Filesystem

Linux supports many modern filesystems; EXT4 is commonly recommended. File types include regular files (text or binary), directories, links, device files (block or character), pipes, and sockets. The standard directory hierarchy is created by the installer, with each directory serving a specific purpose.

/bin – binary executables

/dev – device special files

/etc – system configuration files

/etc/rc.d – startup scripts and config

/home – user home directories

/lib – standard libraries

/sbin – system administration commands

/tmp – temporary files

/root – root user’s home

/mnt – mount points for external filesystems

/lost+found – recovered files after crashes

/proc – virtual filesystem exposing kernel and process info

/var – variable data such as logs

/usr – large hierarchy for applications, libraries, documentation, source code, etc.

Shell and Commands

The shell is the user interface for interacting with the kernel; Bash (Bourne Again Shell) is the default on most distributions. Commands are grouped by function, and shell scripting enables automation. While Bash, Perl, and Python are common scripting languages, Python is often recommended for new scripts.

Linux Applications

A standard Linux system includes text editors (Emacs, Vim), programming languages, X Window system, internet tools, and databases. Vim is highlighted as an essential skill, with many commands illustrated in the article. Package management differs by distribution: Ubuntu uses apt, while CentOS uses yum. Building software from source requires familiarity with Makefiles and the configure/autoconf/make workflow.