A
alias: Create an alias for a command to simplify usage.apropos: Search the manual pages for a keyword or topic.apt-get: Command-line tool for handling packages in Debian-based systems (use apt in newer versions).arch: Display the machine architecture information.awk: Pattern scanning and processing language for text processing.
B
basename: Strip directory and suffix from filenames.bat: A modern alternative to cat with syntax highlighting and Git integration.bash: GNU Bourne-Again SHell, a command language interpreter.bg: Place a job in the background.bzip2: Compress or decompress named files using Burrows-Wheeler block sorting text compression.
C
cat: Concatenate and display the content of files.cd: Change the current directory.chgrp: Change group ownership of files or directories.chmod: Change the access permissions of files or directories.chown: Change file owner and group.cksum: Calculate and display the CRC checksum and byte counts.clear: Clear the terminal screen.cmp: Compare two files byte by byte.cp: Copy files and directories.cron: Daemon to execute scheduled commands.crontab: Schedule periodic jobs using the cron daemon.curl: Transfer data from or to a server, supporting various protocols.cut: Remove sections from each line of files.
D
date: Display or set the system date and time.dd: Convert and copy a file; used for backing up and restoring entire disks.df: Report file system disk space usage.diff: Compare files line by line.dig: DNS lookup utility.dirname: Strip last component from file name.du: Estimate file space usage.
E
echo: Display lines of text or variables.env: Display or set environment variables.exit: Exit the shell or a script.export: Set environment variables.expr: Evaluate expressions.
F
fd: A simple, fast, user-friendly alternative to find.fg: Bring a background job to the foreground.find: Search for files in a directory hierarchy.finger: User information lookup program.free: Display amount of free and used memory in the system.ftp: File Transfer Protocol client.
G
git: Distributed version control system for tracking changes in source code.grep: Search files for lines that match a given pattern; supports regular expressions (regexp).groupadd: Create a new user group.gzip: Compress or decompress files using GNU zip.
H
head: Output the first part of files.help: Display help for built-in commands.history: Show the command history.hostname: Show or set the system’s host name.htop: An interactive process viewer, an improved version of top.
I
id: Display user identity.if: Used for conditional branching in shell scripts.ifconfig: Configure network interfaces (deprecated; use ip instead).ip: Show / manipulate routing, devices, policy routing, and tunnels.info: View detailed documentation for a command or topic.
J
jobs: Display status of jobs in the current session.journalctl: Query the systemd journal for logs.
K
kill: Terminate a process by PID.killall: Kill processes by name.kubectl: Command-line interface for running commands against Kubernetes clusters.
L
last: Display a list of recent logins.less: View files interactively, allowing backward and forward movement.ln: Create links between files.locate: Find files by name quickly.logname: Print current login name.ls: List directory contents.
M
man: Display the manual page for a command.mkdir: Create new directories.mkfifo: Make FIFOs (named pipes).mknod: Create block or character special files.more: View text files one screen at a time.mv: Move or rename files and directories.
N
nano: Simple, easy-to-use text editor.nbd-client: Network block device client.netstat: Print network connections, routing tables, interface statistics.nmap: Network exploration tool and security/port scanner.nohup: Run a command immune to hangups, with output to a non-tty.nroff: Text-formatting program; processes plain text documents for printing. Commonly used for formatting manual pages (manpages).
O
openssl: Toolkit for SSL/TLS cryptography.passwd: Update a user’s authentication tokens (password).patch: Apply a diff file to originals.ping: Send ICMP ECHO_REQUEST to network hosts.ps: Report a snapshot of current processes.pwd: Print name of current working directory.
R
ranger: A console file manager with VI key bindings.read: Read a line from standard input.rg: ripgrep, a fast command-line search tool that recursively searches directories for a regex pattern. Supports regular expressions (regexp).rm: Remove files or directories.rmdir: Remove empty directories.rsync: Remote file and directory synchronization.
S
scp: Securely copy files between hosts on a network.screen: Terminal multiplexer with session persistence.sed: Stream editor for filtering and transforming text using regular expressions.sftp: Secure file transfer program.sleep: Delay for a specified amount of time.sort: Sort lines of text files.ssh: OpenSSH SSH client (remote login program).stat: Display file or file system status.su: Substitute user identity.sudo: Execute a command as another user, typically as the superuser.sync: Flush file system buffers.
T
tail: Output the last part of files.tar: Tape archive utility; store, extract files from an archive.tcpdump: Dump traffic on a network.tee: Read from standard input and write to standard output and files.tmux: Terminal multiplexer that allows multiple sessions in one terminal.top: Display Linux processes.touch: Change file timestamps or create empty files.tr: Translate or delete characters.traceroute: Print the route packets take to network host.tree: Display directories and files in a tree-like format.type: Describe a command.
U
uname: Print system information.unzip: Unpack compressed ZIP files.uptime: Tell how long the system has been running.useradd: Create a new user or update default new user information.userdel: Delete a user account and related files.usermod: Modify a user account.
V
vi: Powerful text editor with a steep learning curve.vim: Improved version of the vi editor.vmstat: Report virtual memory statistics.
W
watch: Execute a program periodically, showing output fullscreen.wc: Print newline, word, and byte counts for each file.wget: Retrieve files from the web via HTTP, HTTPS, and FTP.whereis: Locate the binary, source, and manual page files for a command.which: Locate a command.who: Show who is logged on.write: Send a message to another user.
X
xargs: Build and execute command lines from standard input.xdg-open: Open a file or URL in the user’s preferred application.xlsfonts: List fonts available to X.
Y
yarn: Fast, reliable, and secure dependency management (JavaScript).yes: Output a string repeatedly until killed.
Z
zcat: View compressed files.zip: Package and compress (archive) files.zless: View compressed files with less.zoxide: A smarter cd command that tracks your most used directories, helping you navigate quickly. It’s a modern replacement for autojump, z, and fasd.
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