Essential Linux Commands: A Quick Reference

Posted on Mar 26, 2025 in Business Sciences

Essential Linux Commands

File and Directory Management

• cd – Change directory. Example: cd /home/user (Navigates to the /home/user directory)
• mkdir – Create a directory. Example: mkdir /home/user/new_directory (Creates a new directory)
• ls – List directory contents. Example: ls /home/user (Lists files and directories in /home/user)
• cp – Copy files. Example: cp /home/user/file1.txt /home/backup (Copies file1.txt to /home/backup)
• mv – Move files. Example: mv /home/user/file1.txt /home/new_location (Moves file1.txt to /home/new_location)
• rm – Remove files. Example: rm /home/user/file1.txt (Deletes file1.txt)

System Commands

• clear – Clear the terminal screen.
• pwd – Print working directory (shows the current directory).
• chmod – Change file permissions. Example: chmod 755 /home/user/file1.txt (Sets permissions)
• man – Display manual page for a command. Example: man pwd (Shows the manual for the pwd command)
• vi – Invoke the vi text editor. Example: vi /home/user/file1.txt (Opens file1.txt in vi)
• ps – List currently running processes.
• find – Locate files. Example: find /home/user -type f -name file1.txt (Finds file1.txt in /home/user)
• touch – Update file access/modification times or create a new file. Example: touch /home/user/file1.txt
• more – Display file content screen by screen. Example: more /home/user/file1.txt
• cat – Display file content. Example: cat /home/user/file1.txt
• cal – Display the calendar.
• date – Display the current date and time.
• exit – Exit the shell.
• who – Show who is logged on.

User Management

• addgroup / groupadd – Add a group.
• adduser – Add a user.
• delgroup – Delete a group.
• deluser – Remove a user.
• id – Display user ID information.
• last – Show the last logged-in users.
• login – Change user.
• logout – Log out the current user.
• passwd – Change user password.
• su – Switch user.
• users – List users currently logged in.
• whoami – Display the current user’s username.

Package Management

• apt-cache search – Search for packages.
• apt-get update / install / remove – Update package lists, install, or remove packages.
• dpkg – Install apt packages.

Network Management

• ifconfig – Configure network interfaces.
• ping – Send ICMP echo requests to a network host.
• traceroute – Trace the route packets take to a network host.

Basic Navigation

• / – Root directory.
• . – Current directory.
• .. – Parent directory.

File Operations

• cat – Concatenate files.
• chmod – Change file permissions.
• chown – Change file owner and group.
• cp – Copy files and directories.
• df – Display disk space usage.
• du – Estimate file space usage.
• file – Determine file type.
• find – Search for files in a directory hierarchy.
• gunzip – Uncompress files.
• gzip – Compress files.
• less – View file content (page by page).
• ln – Create hard or symbolic links.
• more – View file content (page by page).
• mv – Move or rename files.
• paste – Merge lines of files.
• rm – Remove files and directories.
• sort – Sort lines of text files.
• tar – Archive files.
• vi or vim – Text editor.