Linux Command Quick Reference

Prints the current logged-in username.

Displays the current working directory.

Lists files and folders within a directory.

• -l: Long list showing permissions, owner, size, and date.
• -a: List all files, including hidden ones (starting with .).
• -i: Displays the inode number (memory address ID).
• -h: Human readable sizes.

Change the current directory.

• ~: Go to home directory.
• ..: Go up one level.
• /: Go to root directory.

Clears the terminal screen.

Shows all commands entered till date in the terminal.

• Use !n to execute the command number n from history.
• Combine with grep to find specific past commands.

Displays the manual for the given syntax.

Press 'q' to quit from the manual mode.

Create a new directory (folder).

Note: md can sometimes be used as a shorthand.

Copy files or directories.

• -r: Copy recursively (needed for directories).
• -v: Verbose (shows what is being copied).
• -u: Only copy if source is newer.
• -p: Preserve timestamps and permissions.

Move or rename files/directories.

Removes files or directories permanently.

• -r: Recursive delete (required for folders).
• -f: Force delete without prompt.
• --: Treats everything after as filename (useful if filename starts with -).

Overwrites the specified file's data to prevent recovery.

• -n: Overwrite N times (default 3).
• -z: Add final overwrite with zeros.
• -u: Truncate and remove file after overwriting.

Displays the contents of a file.

Basic terminal text editor.

Press Ctrl+O to save and Ctrl+X to exit.

Advanced text editor.

Outputs the first part of files (default 10 lines).

Outputs the last part of files.

Use -f to follow appended data (great for monitoring logs).

Allows forward and backward movement through the file.

Press 'q' to quit.

Searches for a pattern in files.

• -r: Recursive search.
• -i: Case insensitive.
• -c: Count matches.
• -n: Show line numbers.
• -E: Extended regex (e.g., for OR operator).

Stream editor for filtering and transforming text.

• -i: Edit file in-place (omit to just preview).
• s: Substitute.
• g: Global replacement (all occurrences in line).

Used for logical searching and text processing (column manipulation).

Prints first column of the file.

Translate or delete characters. Simpler than sed for character replacement.

Powerful alternative to sed, useful for complex regex and indentation.

Sorts lines of text files.

-h enables human-numeric sort (e.g., 2K > 1G).

Prints a sequence of numbers.

Search for files in a directory hierarchy.

• -name "pattern": Exact name (case-sensitive).
• -iname "pattern": Case-insensitive name.
• -type d: Find directories only.
• -type f: Find files only.
• -maxdepth N: Limit search depth.

Change permission of file or directory.

• +x: Make executable.
• -w: Remove write permission.

Create a shortcut for a command.

To make permanent, edit ~/.bashrc.

Schedule a power off.

• -h now: Shutdown immediately.
• -r now: Reboot immediately.
• -c: Cancel a scheduled shutdown.

List open files (used to check running ports).

Display battery health and status.

Check capacity: below 50% is considered poor.

Package and compress files (with encryption).

-e encrypts, -r recursive.

Extract compressed zip files.

GNU Privacy Guard (File encryption).

Decrypt with: gpg -d file.gpg > file.

Command-line network manager.

• device show: Shows IP, DNS info.
• device wifi show-password: Shows current WiFi password.

Download files from the web.

Transfer data from or to a server.

Remote sync (efficiently copies/syncs files).

• -a: Archive mode (preserves permissions).
• -v: Verbose.
• -z: Compress during transfer.

Report file system disk space usage.

-h for human readable format.

Estimate file space usage.

-s summary, -h human readable.

List block devices (disks and partitions).

Debian/Ubuntu package manager.

• update: Reload package index.
• upgrade [pkg]: Install newer versions.
• install [pkg]: Install a package.
• search [pkg]: Search for a package.
• list --installed: List installed packages.

Package manager for snap packages.

• list --all: List all snaps.
• remove [pkg]: Remove package.

Tool for audio/video/image conversion.

• Convert format: ffmpeg -i input.mp4 output.avi
• Extract audio: ffmpeg -i video.mp4 -b:a 192k audio.mp3

Convert images to PDF.

Add --pagesize A4 to force A4 size.

PDF Toolkit (merge, split, rotate).

Merges in1 and in2 into out.pdf.

Downloader for YouTube and other media sites.

Download best video: yt-dlp -f best [URL].

Python command line utility (quick server).

Creates a local web server at port 8000.

Secure file transfer.

Receiver uses: wormhole receive [code].

Generate QR codes in terminal.