Linux Course

Take your first steps in the Linux terminal — pwd for where you are, ls to list, cd to move — running a real Linux environment live in a browser terminal.

Make folders with mkdir, create files with touch and echo's > / >>, and check their contents with cat — all hands-on in a browser terminal.

Learn absolute vs relative paths, how to use the special symbols . .. ~ /, and how to read your location with pwd and ls -l — by moving around in a browser terminal.

Copy files with cp, move and rename with mv, delete files with rm, and remove directories with rmdir and rm -r — with their main options, hands-on in a browser terminal.

Practice Tab completion, reusing history with the arrow keys and history, line editing with Ctrl-A/Ctrl-E/Ctrl-U, and history search with Ctrl-R, hands-on in a browser terminal.

Show the whole file with cat, the start and end with head and tail, and count lines with wc -l — plus the log-checking flow, hands-on in a browser terminal.

Overwrite a file with >, append with >>, feed standard input with <, and send only error output to a separate file with 2> — hands-on in a browser terminal.

Learn how a pipe passes one command's output to the next, counting lines with wc -l, sorting with sort, and the classic sort | uniq to collapse duplicates — hands-on in a browser terminal.

Learn the basics of finding lines containing a string, plus when to use -i to ignore case, -n for line numbers, and -r for recursive search — hands-on in a browser terminal.

Learn how to specify many filenames at once with the * ? [] wildcards, and how find searches by name with -name and by type with -type — hands-on in a browser terminal.

Learn to read the rwx notation and octal numbers in ls -l, rewrite permissions with chmod's symbolic and numeric modes, and the syntax of chown — hands-on in a browser terminal.

Learn to reference variables with echo $VAR and env, what HOME and PATH mean, setting variables with export, and command substitution $(...) — hands-on in a browser terminal.

Learn sequential execution with ;, conditional execution with && (on success) and || (on failure), and how single vs double quotes differ in variable expansion — hands-on in a browser terminal.

Learn to list running processes with ps, check your own PID with $$, and stop a process you sent to the background with & using kill — hands-on in a browser terminal.

Learn to start vi, switch between normal and insert mode, return with Esc, and save with :wq or discard with :q! — hands-on in a browser terminal.

Cross-organize the Linux basics commands — navigation, creating, operations, viewing and searching, permissions, processes, and vi — by category with diagrams and cheat tables as a starting point for review.

Learn the ^ $ . * [] basic regex and grep -E / -o hands-on by running them.

Unlike echo, printf adds no trailing newline; learn %s/%d insertion, \t column alignment, and creating multi-line files.

Learn sed's substitution s///, line extraction -n p, deletion /pat/d, and in-place editing -i hands-on by running them.

Learn awk's column extraction $1 / $NF, the -F separator, NR / NF, and pattern processing hands-on by running them.

Learn awk's BEGIN / END, summing with s += $1, and counting with NR or { c++ } to build aggregation reports hands-on by running them.

Learn sorting, column extraction, and line counts with sort, uniq, cut, and wc, character translation with tr, and output splitting with tee.

Learn xargs for turning pipe output into arguments, plus -n1, -I{}, and find integration by running them hands-on.

Learn the basics of uncompressed archives: bundle with tar -cf, list with -tf, and extract with -xf.

Learn the difference between symbolic links (ln -s) and hard links (ln) hands-on by running them.

Check the differences between two files with diff, and learn to read the unified format that marks removed (-), added (+), and change positions (@@), hands-on.

Check disk usage with du / df, the date with date, the system and user with uname / whoami / id, and sequences and arithmetic with seq / expr, hands-on.

Create a shell script in vi, add #!/bin/sh, make it executable with chmod +x, and run it with ./hello.sh. Illustrated and practiced in your browser.

Assign with name=value and reference with "$name", see how single vs double quotes expand, run $(date) command substitution, do $(( )) arithmetic, and read input. Illustrated and practiced in your browser.

Receive ./a.sh foo bar values with $1 $2 $@ $# $0, supply a default with ${2:--}, check $? and return status with exit 0 / exit 1. Illustrated and practiced in your browser.

Test files, strings and numbers with [ -f ], [ -z ] and -lt, branch with if / elif / else, and route patterns with case. Illustrated and practiced in your browser.