Intro to Linux,
one command at a time.

Print the current working directory.

Change directory. `cd ..` up, `cd ~` home, `cd -` previous.

Push a directory onto the stack and cd into it.

Pop the directory stack, returning to the previous location.

Recursive, indented directory listing.

Recursively list every file below a directory.

Jump back to the previous working directory.

Show the current directory stack, numbered.

Jump to the current user's home directory.

List directory contents. `-l` long, `-a` hidden, `-h` human.

List files (DOS-friendly alias of `ls`).

Create directories. `-p` makes parents as needed.

Remove an empty directory.

Remove files. `-r` recursive, `-f` force. Care.

Copy files or directories.

Move or rename files.

Create an empty file or update its timestamp.

Create a symbolic link.

Detailed file metadata: size, inode, mode, times.

Identify a file's type by content, not extension.

Strip directory and suffix from a path.

Return the directory portion of a path.

Resolve a path to its canonical absolute form.

Rename many files with a pattern.

Overwrite and remove a file to hinder recovery.

Copy files and set mode in one shot.

Print resolved value of a symbolic link.

Shrink or extend a file to an exact size.

Compute and print an MD5 hash.

Compute and print a SHA-256 hash.

Change ext filesystem attributes (e.g. +i = immutable).

List ext filesystem attributes on a file.

Convert and copy raw data blocks. Careful — no undo.

Byte-by-byte compare two files.

Safely create a unique temporary file or directory.

Concatenate and print file content.

Page through a file. `q` quit, `/` search.

Simple pager. Space for next page, `q` to quit.

Show the first N lines of a file.

Show the last lines. `-f` follows new writes.

Concatenate and print files in reverse.

Number the lines of a file.

Print text or variables to stdout.

Compare files line by line.

Canonical hex + ASCII view of any file.

Make a hex dump — or reverse one back to bytes.

Octal / character dump of a file.

Syntax-highlighted, git-aware `cat` clone.

Print sequences of printable characters from a binary.

Formatted output — like C's printf, but from the shell.

Modal editor. `i` insert, `Esc` normal, `:wq` save+quit.

Friendly terminal editor. `Ctrl-O` save, `Ctrl-X` quit.

Search text using patterns. `-r` recurse, `-i` case, `-n` lines.

Walk a directory tree looking for matches.

Locate a command in your PATH.

Locate binary, source, and manual for a command.

Quickly find files by name via the updatedb index.

Reveal how the shell will interpret a command.

Ripgrep — blazing recursive text search.

Simple, fast alternative to `find`.

The Silver Searcher: fast code search.

Snapshot of running processes.

Live process viewer.

Friendlier, colorful process viewer with mouse support.

Send a signal to a process. `-9` = SIGKILL.

Kill processes by name.

Print PIDs matching a name.

Run a command immune to hangups, output to nohup.out.

List jobs in the current shell.

Move a job to background or foreground.

Control systemd services and units.

Edit the current user's scheduled jobs.

Signal processes by name pattern.

Change scheduling priority of a running process.

Run a command with adjusted scheduling priority.

Queue a one-shot job for later execution.

Re-run a command at intervals and show output.

Report how long a command took to run.

Run a command with a wall-clock kill switch.

Block until background jobs / a PID finish.

Run a handler when the shell receives a signal.

Send ICMP echo requests.

Transfer data from or to a URL.

Download files non-interactively.

Open a secure shell session.

Copy files over SSH.

Efficient incremental file sync, local or remote.

Inspect open sockets and listeners (modern netstat).

Show and manipulate routing, devices, and tunnels.

Trace the network path packets take to a host.

DNS lookup utility. Query records directly.

Netcat: read/write TCP & UDP. Swiss-army knife.

Legacy socket inspector. Prefer `ss`.

Legacy interface config tool. Prefer `ip`.

Show or manipulate the ARP cache.

Query DNS interactively.

Simple DNS lookup utility.

Configure kernel packet filtering rules.

Uncomplicated firewall front-end for iptables.

Capture and analyse network packets.

Network scanner — hosts, ports, services.

Live traceroute + ping in one continuously updating view.

Look up domain registration info.

Interactive File Transfer Protocol client.

Interactive file transfer over SSH.

Show wireless interface configuration.

Command-line control of NetworkManager.

Change file permissions. `755`, `+x`, `o-w` …

Change file ownership.

Change the group ownership of a file.

Set the default permission mask for new files.

Execute a command as the superuser. Power. Responsibility.

Switch user. `su -` loads target user's env.

Change a user's password.

Show user and group IDs.

Show POSIX ACLs on a file.

Modify POSIX ACLs on a file.

Safely edit /etc/sudoers with syntax checking.

Create a new user account.

Modify a user account (add groups, shell, home).

Show the groups a user belongs to.

Delete a user account.

Create a new group.

Show or change password expiration policy.

Print system and kernel information.

Disk space usage by filesystem.

Disk usage of a path. `-s` summary, `-h` human.

Memory usage at a glance.

How long the system has been up.

Print the effective user.

Show recently executed commands.

The manual. Your most reliable contact.

Print or set the system date.

Show or set the system's hostname.

List block devices in a tree.

Print or control the kernel ring buffer.

Query the systemd journal.

Attach a filesystem to a mount point.

Restart the system.

Power off or halt the system.

Print or set environment variables.

Set an env var for child processes.

Create a shortcut for a longer command.

Wipe the visible terminal buffer. `Ctrl-L` too.

Close the current shell session.

Display CPU architecture information.

List USB devices attached to the system.

List PCI devices on the bus.

List open files and the processes that hold them.

Pretty-print how long the system has been up.

Show who is logged on.

Show the last logged-in users.

Show and change system time / timezone.

Query or change the system hostname and metadata.

Inspect systemd-logind sessions.

Read or write kernel runtime parameters.

Load a kernel module (with its dependencies).

Show the status of loaded kernel modules.

Print the running kernel release string.

Show or enable swap devices and files.

Partition table manipulator for block devices.

Show block-device UUID, label, and filesystem type.

List units systemd currently knows about.

Cancel a pending scheduled shutdown.

Debian/Ubuntu package manager.

Fedora/RHEL package manager.

Arch package manager.

Cross-distro sandboxed package manager.

Homebrew: user-space package manager.

Low-level Debian package tool.

Refresh available package lists.

Install newer versions of installed packages.

Query and manage RPM packages directly.

AUR helper for Arch — like pacman + AUR builds.

Install Python packages from PyPI.

Install Node.js packages from the registry.

Install and run sandboxed desktop apps.

Archive files. `-x` extract, `-t` list.

Count lines, words, bytes.

Sort lines of text.

Filter adjacent duplicate lines. Pair with sort.

Pattern-scanning and processing language.

Stream editor for transforming text.

Build and execute commands from stdin.

Extract sections from each line.

Translate or delete characters.

Read stdin, write to stdout AND to files.

Sling JSON on the command line.

Format text into columns.

Merge lines of files side by side.

Wrap each input line to fit a given width.

Reverse the characters of each line.

Split a file into fixed-size pieces.

Repeatedly print a string until killed (feeds `y` to prompts).

Convert tab characters to spaces.

Convert leading spaces back to tabs.

Line-by-line compare two sorted files.

Join two sorted files on a common field.

Compress files into a .zip archive.

Extract files from a .zip archive.

Compress a file to .gz (removes the original).

Decompress a .gz file back to the original.

Encode / decode data as Base64.