Mastering Linux Command Line

Master the Linux architecture from hardware and kernel to the shell, and learn how multitasking, multi-user security, and a hierarchical filesystem enable efficient, secure operation.

Explore the landscape of shells, including bash, zsh, and fish, and learn how a shell sits above the kernel and allows having and switching between multiple shells.

Set up your Linux lab by installing on a local desktop or laptop, or run a VM with VirtualBox or VMware Workstation, or use AWS or Azure.

Learn how to connect to a Linux machine using secure and insecure protocols, including ssh and telnet, and choose appropriate client tools for remote access.

Explore the Linux command structure by learning commands and their arguments, with examples like pwd, ls, cd, cat, and rm, while noting caution with deleting non-empty directories.

Explore how to access Linux help with man pages, including sections, commands like man -k, -f, and -i, and using tab completion and 'what is' for quick command overviews.

Differentiate internal and external commands: internal ones are built into the shell and fast; external ones rely on separate binaries and subprocesses.

Boost your command-line efficiency by using the up arrow to recall commands, the history feature to list past commands, and ctrl-r to perform reverse history search.

Explore how the Linux file system centers on a single root, with partitions mounted to folders like /bin and /home, and learn the role of mount points and lost+found.

Identify regular files, directory files, block device files, character device files, named pipes, symbolic links, and socket files, and learn how Linux treats everything as a file.

Explore how Linux assigns each user a home directory under /home, such as /home/john and /home/mary, and how the HOME variable reveals it with echo $HOME.

Learn that Linux treats file and directory names as case sensitive, and avoid problematic characters; extensions have no inherent meaning in Linux. Use touch to create files in practice.

Explore Linux file system paths by distinguishing absolute paths and relative paths, and using dot and dot dot to reference current and parent directories from root to home.

learn what dot files are, why they stay hidden by default, and how to reveal them with ls -a or ls -la to explore dot files for shell customization.

Master the linux command line by using pwd, tree, and ls to navigate the file system, switch between folders with cd and cd -, and reach home quickly.

Explore linux wildcards, including the asterisk, question mark, and square brackets; learn how patterns match 0 or more characters and a single character, including negation with exclamation mark, with examples.

Explore basic Linux commands: use echo to display messages and variables, date to show current date and time, cal to view calendars, and expr to evaluate expressions with proper escaping.

Explore chaining commands with a semicolon to run multiple commands, observe their sequential outputs, and see why this is handy for admins and programmers, plus a peek at command substitution.

Explore command substitution by embedding a command's output inside an echo statement using backticks. See how inserting date produces a live timestamp that changes with each execution, useful for scripts.

Learn to create your own commands with alias in the NIC system, chaining tasks to navigate to the linux-course folder and list contents, and set permanent aliases via shell profiles.

Learn to create and remove directories using mkdir and rm, including recursive and empty directory handling, with -p for nested structures and navigating with cd and parent paths.

Learn how to copy directories recursively with -R, rename directories, and use the move command to relocate directories within the file system while preserving contents.

Explore the wc command to count lines, words, characters, and the longest line across files, with practical examples and options such as -l, -w, -m, -c, -L, and help references.

Mastering Linux command line: learn to display file contents with cat, view line numbers with cat -n, explore tac for reversing line order, and use rev to reverse each line.

Use the more command to view large files, navigate with enter, space, and q, compare it with cat, and control wrapping and blank lines with -f, -s, and +N.

Explore the less command for viewing files, compare it with more, and learn navigation, searching, and jumping to specific lines for efficient inspection of large text files.

Learn to view file contents with head and tail. Head shows top lines, tail shows bottom lines (default ten). Use minus options and tail -f for real-time log watching.

Learn how to copy, move, and remove files and directories using cp and mv, including options for updating, preserving ownership, and recursive operations.

Explore the vi editor to create a file, enter insert mode, type sample text, and save or exit using commands like escape, :w, :q, and :wq.

Learn how to split large files with the Linux split command, by lines or by chunks, set the number of output files, and customize the resulting prefixes for easy identification.

Explore standard input and output in linux, using redirection and pipes to route input from files and send output to files or commands, and manage file descriptors 0, 1, 2.

Learn how to redirect command output to files, understand append versus overwrite, use input redirection, and pipe data between commands to count lines and process text.

Learn to redirect command output to files and to /dev/null, and understand that in Linux, everything is a file, including terminals, which are device files that reflect input and output.

Learn to use file descriptors 1 and 2 and redirect operators to route standard output and standard error to log files, and to direct both streams to the same file.

Learn how to use the pipe symbol to chain commands, apply sort and uniq, and count unique lines with wc to compare two animal-name files and identify duplicates.

Explore how Linux manages users and groups, including user IDs, group IDs, and primary groups, plus how permissions are inherited and stored in /etc/passwd and /etc/group.

The root account in linux acts as the administrator with full permissions, UID 0 and GID 0, home /root, and shell /bin/bash; using /sbin/nologin prevents login.

Switch users on the command line with su, including switching to Mary and to root, and use su - to invoke the user's login shell and password-protected home directory.

Explore how the sudo command grants root privileges to run commands as another user, enabling tasks like adding or deleting users with proper authorization.

Understand file attributes in Linux, including name, creation and modification timestamps, access times, owner and group, permissions for owner, group, and others, and the limited role of file extensions.

Explore file permissions for owner, group, and others—read, write, and execute; this theoretical video covers ls -l outputs, file types, and ownership.

Explore the ls -l output on a linux system, decode the total line and block allocation, and interpret the file type, permissions, links, owner, group, size, and timestamps.

Learn to change file owner and group, and adjust owner, group, and others permissions using chown, chgrp, and chmod, with examples of rwx and recursive options.

Mastering Linux command line explains numeric file permissions, mapping read, write, execute to 4, 2, 1, and shows how to set owner, group, and others with octal values using chmod.

Mastering linux command line explains how the umask sets default permissions for new files and directories by subtracting from base modes (files 666, directories 777), with system-wide or per-user configuration.

Explore the file command and how it reveals a file or directory type, including ASCII text, regular and empty files, and symbolic links, while supporting wildcards.

Master vi editor basics, including command mode and insert mode. Learn to open files, edit text, and save or quit with colon, w, and wq in a hands-on Linux session.

Master vi editor basics: open and view files, switch between command and insert modes, insert text, navigate, and save. Create new files, quit safely, and revert unsaved changes.

Master vi deletion techniques across characters, words, and lines. Use x and X for characters, dw for words, dd or D for lines, and DG for end of file.

Master vi navigation using h j k l for cursor movement and w e for word jumps; use G or 1G to reach top lines, scroll with ctrl-d or ctrl-u.

Explore practical vi editor techniques in part 4, including deleting and changing lines, replacing words, editing from cursor to end, joining lines, swapping characters, and undoing changes.

Copy and paste lines in vi using y and p, yank multiple lines, and delete with dd. Move blocks with colon ranges to a target line.

Master vi editor search and replace techniques using forward slash and question mark for forward and backward searches, with line-range and global options for replacements.

Learn to search in the vi editor with ignore case, toggling case sensitivity on and off, using sample text from mixed upper and lower case to find 'application'.

Master the basics of regular expressions in Linux, using grep and grep -E to filter lines, match patterns with ^, $, and the dot, yielding precise file and text searches.

Explore advanced regular expressions using character classes, anchors, and negation to filter lines with grep, practicing start and end patterns, numbers, and mixed case.

Explore the cut command to extract fields by character or delimiter, specify ranges or multiple fields, handle custom delimiters, skip nonconforming lines, and format output for practical data processing.

Master the paste command to combine lines from multiple files into a single delimited output, with flexible delimiter options and practical use in data processing and scripting.

Learn how the tr command translates characters, maps one character to another, and handles case conversion with character classes; explore examples like replacing spaces with tabs and deleting digits.

Discover how the tee command reads standard input, writes to standard output and to files, optionally appends, and enables chaining by piping output to other commands and grep.

Master sort and uniq to order and deduplicate file lines, count duplicates, and extract unique entries. Sort numerically, reverse results, and ignore case with -n -r -d -u -i.

Master the grep command to search for strings, display matching lines, and apply options like -i, -v, -n, -c, -r, -B, -A, -E, including piping and context-aware multi-pattern searches.

Mastering the find command, learn to locate files by name, type, permissions, size, and ownership; execute actions like delete or modify permissions recursively, with examples using tilde and wildcards.

Learn to use the find command to locate files by modification or access time and by size, including exact and recent time windows, and to execute actions on matches.