Linux Administration: The Complete Linux Bootcamp

Explore what a Linux distribution is, including the kernel, package management, and open source components that define distros used on servers, desktops, and embedded devices like Ubuntu and Red Hat.

Install ubuntu in a virtual machine with VirtualBox or VMware, allocate at least 4 gb ram and 25 gb disk, download the Ubuntu iso, enable virtualization, and complete the installation.

Update your Ubuntu system with sudo apt update and sudo apt full-upgrade, then install VirtualBox guest additions and learn to take VM snapshots for rollback.

Guide windows users through migrating to linux as the main desktop OS, showcasing linux mint and ubuntu, and configuring settings, dock, and apps via ubuntu software.

Explore the Linux terminal in depth, learning about terminals, terminal emulators, shells (bash), and how commands flow from user to kernel, including consoles and multiple tabs.

Explore the structure of Linux commands by examining command name, options, and arguments, with examples like ping, ls, and df, and learn how options can be grouped and varied.

Master the built-in Linux help system by using man pages to read command documentation, distinguish executables from shell built-ins, and search with man -k and apropos.

Mastering the terminal's tab completion boosts efficiency by auto-completing commands, filenames, and directories in bash and other shells. Use tab twice to view multiple matches and avoid mistakes.

Learn essential Linux Bash shortcuts to speed admin tasks: clear screen (ctrl-l), navigate (ctrl-a/e, history arrows), edit with ctrl-u, and manage processes with ctrl-c and ctrl-z.

Explore how bash stores command history in .bash_history, manage history size with HISTFILESIZE and HISTSIZE, and use history and recall shortcuts to rerun or search commands.

Explore running commands with a leading space to avoid history logging. Configure HISTCONTROL to ignorespace or ignoredups, note Ubuntu defaults ignorespace while CentOS may differ, and persist settings in .bashrc.

Set the hist time format variable to attach timestamps to history entries, displaying date and time with every command, and persist the setting by appending it to ~/.bashrc with >>.

Learn the difference between root and non-privileged users and how to gain temporary root access with sudo, su, and passwd, and manage root privileges.

Discover how the Linux file system stores and retrieves data, from the root / to mount points like /media, and how USB drives mount under a hierarchical filesystem.

Explore the Linux filesystem hierarchy standard and its key directories, from /bin and /sbin to /usr and /var, and learn how they host binaries, configs, and system administration tools.

Master absolute and relative paths with cd, pwd, and ls; know /, /home, and ~ as the home directory, and visualize structures with tree.

Explore the ls command in depth, mastering common options (-l, -a, -h, -S, -R) to display files, sort by size or extension, show hidden items, and understand permissions.

Explore Linux file timestamps—atime, mtime, and ctime—how they are stored as epoch seconds, viewed with ls and stat, and manipulated with touch using -a, -m, -d, -t, and -r.

Sort files by timestamp with ls, using -t for modification time (newest first) or -u for access time, and reverse the order with -r or --reverse.

Explore how Linux determines file types from the header rather than extensions, and use the file command and ls -F to identify regular files, directories, and devices.

Learn to view text files in Linux with the cat command, display multiple files, number lines with -n, and redirect output to new files.

Use less to view long files a page at a time. Navigate with the arrow keys, search with /, jump with g/G, cycle matches with n/N, and exit with q.

Master tail, head, and watch to view file contents, read specific lines with -n, follow updates in real time with -f, and monitor logs.

Master creating files and directories in Linux with touch and mkdir, including timestamps, spaces handling with quotes, and using -v and -p for verbose and parent creation.

Master copying files and directories with the cp command, using -v for verbose output, -i for prompts, -r for recursion, and -p to preserve permissions and ownership.

Master the mv command to move and rename files and directories in Linux, including multiple files, pattern matching, and handling overwrites with -a, -n, and -u options.

Master removing files and directories with rm, using -i for prompts, -r for recursive deletion, and -f for force, and learn how shred securely overwrites before removal.

Learn how pipes connect command outputs to inputs in Linux, enabling chaining and redirection with commands like ls, head, tail, grep, and wc to filter and count data.

Redirect command output to files with > and >>, redirect errors with 2> and 2>>, and use cut and tee to filter, save, and display results via pipes.

Learn to use which to reveal the absolute path of executables and plocate to locate files, update the locate database, and refine searches with -a, -b, -r, -e, and -i.

Learn to use the find command to locate files and directories by name, type, size, time, and ownership, including -delete and -ls options.

Learn to use find -exec to run cat on each file in /etc modified in 24 hours, and copy results with cp to /root/backup, using -ok for confirmation.

Learn how to search for string patterns in text files using grep, including regular expressions, case handling, word matching, line numbers, binary files, recursive search, and piping.

Learn to use the strings command to extract printable ascii from binary files, revealing embedded text such as help in executables and in disk partitions.

Learn how to compare file contents using cmp for byte-by-byte checks and sha256 hashes, and use diff to reveal line-by-line text differences, with patching and real-world examples.

Explore the basics of the vim text editor, a powerful command-line interface tool for Linux. Master the three modes: command, insert, and last line, and essential editing commands.

Explore vim editing, run shell commands, search with / or ?, navigate with n/N, jump to end with G, copy, cut, paste with d, y, p, and permanence via .vimrc.

Master vim navigation and multi-file editing with -o, -d, and vimdiff; move to lines by number, jump to end with G or to start with gg, and copy, paste, compare.

Learn to archive and compress files and directories with tar, gzip, and bzip2, including creating, extracting, listing, and excluding tarballs.

Explore inodes and hard links, showing how directories map filenames to inode numbers and how multiple names can point to the same data.

Compare symlinks with hard links, learn to create symlinks using ln -s, and understand how they reference inodes and targets, and how moving files affects them.

Learn to automate text edits with sed, the stream editor, performing substitutions with s/old/new/g, editing files in place with -i, and backing up before changes across multiple systems.

Discover how to automate sshd_config configuration with sed in real-world linux administration tasks on ubuntu, using regex patterns to disable root login and password authentication with a single command.

Master regex basics and apply them with grep to search and transform text in Linux administration. Use anchors, character sets, and ranges, and back up before editing system files.

Master advanced sed and regex techniques for sysadmins, including delete, insert, and append, in-place edits, and automating SSH policy enforcement across multiple servers, with testing and sudo safety.

Explore linux authentication via /etc/passwd and /etc/shadow, reveal passwd field details and how shadow stores hashed passwords with salts and password expiration data.

Understand how linux groups control file permissions through a primary and secondary group. Use groups and id to view a user's groups and examine /etc/passwd and /etc/group for IDs.

Learn to create and manage Linux user accounts with useradd, set passwords, assign home directories and shells, and manage primary and secondary groups and account expiration.

Modify existing Linux user accounts with usermod to adjust comments and primary or secondary group memberships, and remove accounts with userdel, including optional removal of home directories.

Create an admin user and grant root access by adding them to the sudo or wheel group, then verify privileges with sudo and root commands.

Learn to create, rename, and delete Linux groups with groupadd, groupmod, and groupdel; manage users with usermod -G and -a, and distinguish primary from secondary groups.

Explore Linux user account monitoring and understand real vs. effective user IDs, using whoami, id, who, w, uptime, and last to track logins and activity.

Understand Linux file permissions across owner, group, and others with read, write, and execute modes. View with ls -l, modify with chmod, and note root can change ownership.

Convert linux file permissions between symbolic and octal notations by summing r=4, w=2, x=1 for owner, group, and others, with examples like 0755 and 0644, and verify with stat.

learn to use chmod to change file and directory permissions with symbolic and numeric modes, specifying user categories (u,g,o,a), operations (+,-,=), and permissions (r,w,x) plus recursive and reference options.

Explore how directory permissions differ from file permissions, showing how read, write, and execute bits affect listing, entering, and modifying directories, and why parent directory permissions govern deleting files inside.

Combine find and chmod to set files to 640 and directories to 750, using -type f and -type d with -exec chmod in the home directory.

Learn to change file and directory ownership and group with chown and chgrp in Linux, managing permissions for owner, group, and others, using root or sudo, and recursive -R.

Explore Linux file permissions and the suid set user id bit, which runs executables with the owner's privileges. See security implications through cat, /etc/shadow, and find -perm -4000.

Set sgid on directories to make new files and subdirectories inherit the directory's group, enabling secure, group-owned sharing for programmers.

Explain the sticky bit, a directory permission that restricts deletion to owners in world-writable directories like /tmp, and show how to set and verify it with chmod and ls -l.

View the current umask and set the base permissions used when creating new files and directories, such as 0664 for files and 0775 for directories.

Explore how Linux file attributes supplement permissions on ext4, and learn to view and modify them with lsattr and chattr, including append (a), no atime updates (A), and immutable (i).