LICM study plan

Install a Linux distribution in a virtual machine and confirm you can log in at a text console and a graphical session

Navigate the filesystem from the shell using absolute and relative paths, and explain the difference between the root directory and a user home directory

Create, copy, move, rename, and delete files and directories, then verify each change with ls and find

Read the man pages and --help output for five unfamiliar commands and summarize what each option does in your own notes

Build pipelines with grep, cut, sort, uniq, wc, and tee to filter and summarize a large text file

Redirect standard input, output, and error to files and to /dev/null, and explain the difference between > and >>

Search the filesystem with find using name, type, size, and modification-time predicates, and combine find with -exec

Edit configuration files confidently in vim or nano, including searching, replacing, and saving without leaving stray backup files

Compress and archive directories with tar and gzip, then extract them into a different location and verify the contents

Explain the boot sequence from firmware to initramfs to the init system and identify which component handles which job

Start, stop, enable, and check the status of services with systemctl, and read the journal for one failed unit

Describe the Linux filesystem hierarchy and state where configuration, logs, binaries, and variable data belong

Create and mount a filesystem on a loopback file, then add it to /etc/fstab and confirm it mounts after a reboot

Identify the kernel version, distribution release, and architecture of your system using uname and the distribution's release file

Manage users and groups with useradd, usermod, groupadd, and passwd, and explain what each field in /etc/passwd and /etc/shadow means

Explain the permission bits for owner, group, and other, and predict the effective access for a given file and user before testing it

Set and clear the setuid, setgid, and sticky bits, and describe a realistic situation where each is appropriate

Change ownership with chown and chgrp and adjust modes with chmod in both symbolic and octal notation

Configure a umask and demonstrate how it changes the default permissions of newly created files and directories

Create and use sudo rules safely, including editing a sudoers drop-in with visudo and testing that a restricted user can run only the allowed command

Generate an SSH key pair, copy the public key to a host, and disable password authentication in a test environment

Explain how file permissions, ownership, and special bits interact with root privileges and why root can bypass most checks

Audit a directory for world-writable files and files with no valid owner, and explain the risk each represents

Describe the purpose of PAM, the shadow password file, and account aging fields, and expire a test account password

Locate files and binaries using locate, updatedb, which, whereis, and type, and explain when each is the right tool

Use package management to search for, install, query, and remove software, and find which package owns a given file

Read and edit text streams with sed and awk for simple substitutions and field extraction

Schedule a recurring job with cron and a one-time job with at, then verify both ran by checking logs and output files

Use hard links and symbolic links correctly and explain how deleting the original affects each

Explain the difference between free software and open source licensing, and name the obligations of the GPL versus a permissive license

Describe how a Linux distribution is assembled from a kernel, userland, package manager, and community governance, using two distributions as examples

Identify common open source contribution paths (bug reports, documentation, translation, code) and the norms of a typical mailing list or issue tracker

Navigate the filesystem hierarchy and use man page sections, apropos, and info to answer questions without searching the web

Describe the roles in a typical open source project and how decisions are made in a meritocratic community

Complete a timed practice set of at least 60 mixed questions and review every wrong answer to the underlying concept

Re-run the hardening checklist and permissions lab from memory, checking each command against your notes only after attempting it

Explain aloud, without notes, the boot process, permission evaluation order, and the purpose of sudo, PAM, and the shadow file

Fix five deliberately broken configurations in a test virtual machine, such as a bad fstab entry, a wrong sudoers rule, and a service that will not start

Write down the ten facts you are least confident about and verify each one against man pages or official project documentation