Linux Commands Cheat Sheet

Prints the current working directory's full path — the fastest way to answer 'where am I right now?'

Lists every file in the current directory, including hidden dotfiles, in long format — permissions, owner, size, and last-modified date for each.

Change directory. cd ~ jumps straight to your home directory, cd - jumps back to the previous directory you were in, cd .. moves up one level.

Creates a directory, including any missing parent directories in one shot — without -p, mkdir fails if the parent doesn't already exist.

Copies a file, or an entire directory recursively with -r. Without -r, cp refuses to copy a directory at all.

Moves or renames a file or directory — Linux doesn't distinguish between the two operations; renaming is just moving within the same directory.

Recursively force-deletes a file or directory with no confirmation prompt and no trash bin to recover from.

Searches a directory tree for files matching a name pattern. Add -type f to match only files, or -mtime -1 to match ones modified in the last day.

Prints a file's entire contents straight to the terminal. Great for short files or piping into another command; less great for anything long enough to scroll past.

Pages through a file interactively — arrow keys or space to scroll, / to search, q to quit. Unlike cat, it doesn't load the whole file into your terminal's scrollback at once.

Show just the first (head) or last (tail) N lines of a file. The default, with no -n, is 10 lines.

Follows a file's contents live as new lines are appended — the standard way to watch a server's log file update in real time while you reproduce a bug.

Creates an empty file if it doesn't already exist, or just updates its last-modified timestamp if it does.

Opens a file in a simple, beginner-friendly terminal editor with its shortcuts printed on screen — the safe default before you reach for vim.

Shows a permission string like -rwxr-xr-- next to each file: file type, then three permission triplets for owner, group, and everyone else, in that order.

Sets exact permissions using octal notation. Each digit is read+write+execute added up: read=4, write=2, execute=1 — so 7 (4+2+1) is full access, 5 (4+1) is read+execute, and 755 means the owner gets everything while everyone else can read and run it, not modify it.

Adds execute permission without touching any of the other permission bits — the usual, minimal fix for 'permission denied' when running a script you just wrote or downloaded.

Changes a file's owner and group in one command. Usually requires sudo unless you already own the file and are only changing its group.

Runs a single command with elevated (root) privileges. Prompts for your own password, not root's, and logs exactly who ran what.

Pipes the output of cmd1 directly into the input of cmd2, with no temp file in between. The core idea behind almost every 'clever' one-liner you'll see.

Redirects a command's output to a file, completely overwriting whatever was there before — with no confirmation.

Redirects output to a file, appending to the end instead of overwriting it — the one-character difference from > that matters enormously.

Redirects just the error output (stderr) to a file, separately from normal output (stdout). Use 2>&1 to merge stderr into wherever stdout is already going.

Searches a file's lines for a pattern. -i ignores case, -r searches every file in a directory recursively, -v inverts the match (show lines that don't match).

Sorts lines alphabetically, then collapses adjacent duplicate lines into one. uniq only removes duplicates that are already next to each other, which is exactly why it's almost always paired with sort first.

Counts lines in a file, or in piped input. -w counts words instead, -c counts bytes.

Lists every running process on the system, with owner, CPU/memory usage, and the exact command that started it.

A live, auto-refreshing view of running processes sorted by resource usage. htop is a friendlier drop-in replacement if it's installed.

Plain kill asks a process to terminate gracefully (sends SIGTERM, giving it a chance to clean up). kill -9 force-kills it immediately, skipping that cleanup entirely.

Runs a command in the background, immediately freeing up the terminal for something else.

jobs lists background jobs in the current shell session; fg brings one back to the foreground; bg resumes a paused job in the background.

Runs a command in the background that keeps running even after you close the terminal or log out — without nohup, a background job is killed the moment its parent shell exits.

Sends repeated packets to a host and reports whether, and how fast, it responds — usually the very first thing to check when something 'isn't working.'

Fetches a URL's response and prints it to the terminal. curl -I fetches just the headers, curl -o file.html saves the response straight to a file instead of printing it.

Downloads a file from a URL directly to disk. -c resumes an interrupted download instead of starting over from zero.

Opens a secure remote shell on another machine — the standard way to log into and work on a remote server.

Copies a file to (or from) a remote machine over SSH, using the same authentication as an ssh login.

Shows this machine's network interfaces and their IP addresses. ip addr is the modern command; the older ifconfig still works on many systems but is considered deprecated.

Shows disk space usage for every mounted filesystem, in human-readable sizes (GB/MB) instead of raw byte counts.

Shows the total size of a directory. Without -s, du recursively lists the size of every subdirectory too, which gets noisy fast on a big tree.

Shows total, used, and available RAM and swap, in human-readable sizes.

Prints system information: kernel name, hostname, kernel version, and architecture, all in one line.

Checks whether a systemd-managed service is running, and shows its recent log output right in the same command.

Follows a systemd service's logs live — the systemd-managed equivalent of tail -f on a plain log file.

On Debian/Ubuntu: refresh the package list, then install a package. dnf install on Fedora/RHEL, pacman -S on Arch — the concept (refresh index, then install) is identical everywhere.

Uninstalls a package. apt purge additionally removes its configuration files, apt remove leaves them in place.

Creates a compressed archive: c=create, z=gzip compression, v=verbose (list files as it works), f=the filename that follows.

Extracts a .tar.gz archive back into files — same flags as creating one, but x for extract instead of c for create.

Extracts a .zip archive into the current directory.

Prints the currently logged-in username.

Prints the PATH variable — the list of directories the shell searches, in order, whenever you type a command name. If a command isn't found, checking this is the first thing to do.

Sets an environment variable for the current shell session and everything launched from it. A plain API_KEY=abc123 without export only sets it for the current shell, invisible to anything it runs.

Creates a shorthand for a longer command. Add it to your shell config file (~/.bashrc or ~/.zshrc) to make it permanent across sessions instead of just the current one.

Re-loads your shell config file into the current session, so a change you just made (a new alias, a PATH update) takes effect without closing and reopening the terminal.

Searches your command history for a previous command you half-remember typing.