Learn Linux and prepare for Job Interview

Trace the history of Unix and the creation of Linux, explaining how Linus Torvalds' free, open source kernel evolved from Minix-inspired ideas into GNU Linux distributions.

Linux is an open source, free, multitasking, multi user operating system developed by the Linux community. Unix is licensed and not open source, developed at Bell Labs.

Explore Unix and Linux architecture from application programs to the shell, kernel, and hardware; learn kernel memory and file management, and how shells like bash, sh, and csh interpret commands.

Explore the Linux directory structure from the root slash to key folders like /bin, /usr/bin, /lib, /proc, /var, and /home, and distinguish root from /root.

Explore basic Linux commands, environment variables with the dollar sign, and the path variable, including pwd for the present working directory and cat for concatenation and file display.

Master basic Linux commands with hands-on practice, using ls, cd, pwd, cat, echo, and clear, navigating the tilde home directory and binaries, and locating commands with which and man pages.

Explore linux directories and absolute versus relative paths, including special dirs dot, dot dot, root, and tilde. Master cd, pwd, mkdir, mkdir -p, and rm -rf for navigation and management.

Explore absolute and relative paths, use dot and cd dash, and manage directories with mkdir -p and rm -r or rm -rf, while ls shows hidden files.

Learn linux by listing files with ls, using -l for long format, -t to sort by modification time, -h for human readable sizes, and -a to include hidden files.

Master ls by listing files, including hidden ones with -a; use -l long format, -la for everything, -h for human readable sizes, and -t to sort by last modified date.

Explore hard links and symbolic links in Linux, and compare how they reference inodes. Learn inode roles, file metadata, and how links relate to file descriptors and the file system.

Learn how to create and manage links in Linux using the ln command, including soft (symbolic) links and hard links, their differences, and practical examples with directories and files.

Learn Linux file and directory permissions, including rwx bits, owners and groups, and both numeric and symbolic modes, with chmod and special bits like setuid, setgid, and sticky.

Explore linux file and directory permissions, view and modify owner, group, and other bits with numeric and symbolic chmod, and understand setuid, setgid, and sticky bits.

Learn to find files and directories using the find and locate commands, with -name, -iname, -exec, wildcards, and updating the locate database for efficient searches.

Learn to view and edit files in linux using the nano editor, and master commands like cat, more, less, head, and tail with common dash options.

Master Linux file viewing with cat, more, less, and head or tail for real-time log monitoring, then learn nano basics like search, replace, cut, copy, paste, and exit.

Edit files with Vim or Vi and compare Vi versus Vim versus Vue. Discover essential shortcuts for editing, inserting, saving, quitting, and using visual mode, yank, delete, paste, and search.

Master vi/vim for editing files: use insert modes i, I, a, A, o; navigate to first and end of lines; save, quit, or save and quit; copy, paste, and search.

Practice copying and moving files with cp and mv, then rename or delete using rm, while noting cp creates copies and mv renames. Be mindful of wildcards to avoid deletions.

Learn Linux file descriptors (stdin 0, stdout 1, stderr 2) and redirect input from a file, output or errors to a file, using > for overwrite and >> for append.

Master input and output redirection, saving command output to text files, using sort with file input, appending results, and silencing standard error with /dev/null.

Compare files in Linux using diff and side-by-side with sdiff, observing added or missing lines and practicing with vim for viewing file text.

Learn Linux transfer files over network by using scp to copy files between local and remote servers, with SSH keys, source and destination paths, and optional renaming.

Learn how to create and persist shell aliases, like mapping c to clear, and understand where to place them in bashrc and profile for login vs non-login shells.

Explore how environment variables differ from regular variables, define them in login shell profiles or system-wide profiles, and apply changes with source or dot commands.

Explore linux processes and job control through essential commands like ps, top, and kill, and learn how to manage foreground and background tasks with bg, fg, and jobs.

Explore Linux processes and job control by using ps to list processes, top or htop for resource view, and manage foreground and background jobs with bg, fg, and kill signals.

Learn to schedule repeated tasks with cron by using crontab -l and -e, configuring every minute, editing with vim, and verifying with tail -f.

Learn to view and analyze Linux command history with the history command, inspect the bash history file and histfile, and consider when to clear or disable it to protect credentials.

Learn to use sudo and su to switch users, explore the sudoers file, and safeguard Linux systems from misconfigurations and risky root access.

Master Linux hands-on user and group management with ad user. Create and assign users to sudo, inspect id and groups, and safely delete users with home directory options.

Traverse the Linux boot process from BIOS through MBR and Grub to the kernel. The kernel mounts the root filesystem, loads init ramdisk, and starts runlevel programs via systemd targets.

Explore Linux file system basics with hands-on commands like df, du, and ls, learn how to read disk usage, and understand mounts, directories, and relative paths.

Learn the basics of shell scripting in Linux, covering variables, special variables, operators, comments, case statements, and loops with functions, all run by the Unix shell.

Learn how Linux shell operators work with variables, quotes, and echo, using export and arithmetic expressions to perform addition, subtraction, multiplication, division, and modulus.

Learn how to implement decision making in shell scripting using if-else constructs and case statements, with practical examples of equality, inequality, and relational tests.

Learn shell scripting loops, including while and for loops, with syntax demonstrations and practical examples, and explore break, continue, and other loops like until or select.

Explore shell scripting basics by creating scripts with a shebang, setting executable permissions, and using special variables like $0, $1, $#, $*, $@, $?, $$, and $!.

Explore linux shell functions by defining a simple hello function and invoking it by name to echo Hello, world. Understand that function invocation mirrors basic programming, with or without brackets.

Explain what Linux is as a Unix-based kernel, its open-source GPL nature, core components like shells and GUI, and its differences from Unix, including LILO bootloader.

Practice Linux interview questions and learn key concepts like mv for renaming files, inodes, process IDs, at for scheduling, distros, swap space, bash, root, CLI and GUI.

Learn Linux interview preparation part 3 covers virus misconceptions, Linux file permissions, vi and vim basics, redirection, grep, and commands for uncompressing zip files and editing files.