List of Common Ubuntu Commands

File and Directory Management

• ls - List directory contents
• ls -a - List all files, including hidden files
• ls -lh - List files with human-readable sizes
• ls -R - List files in directories and subdirectories
• cd [directory] - Change the current directory
• cd .. - Move up one directory
• cd - - Switch to the previous directory
• cd ~ - Change to the home directory
• pwd - Print the current working directory
• mkdir [directory] - Create a new directory
• mkdir -p [path/to/directory] - Create parent directories as needed
• rmdir [directory] - Remove an empty directory
• rm [file] - Remove a file
• rm -r [directory] - Remove a directory and its contents recursively
• rm -f [file] - Force remove a file without confirmation
• cp [source] [destination] - Copy files and directories
• cp -r [source] [destination] - Copy directories recursively
• mv [source] [destination] - Move or rename files and directories
• touch [file] - Create an empty file or update the timestamp of a file
• cat [file] - Concatenate and display file content
• head [file] - Display the first 10 lines of a file
• tail [file] - Display the last 10 lines of a file
• tail -f [file] - Follow the end of a file in real-time
• find [path] -name [filename] - Search for files by name
• find [path] -type f -name '*.txt' - Find all text files
• file [filename] - Determine the file type
• ln -s [target] [link] - Create a symbolic link
• du -sh [directory] - Display disk usage of a directory in human-readable format
• stat [file] - Display file or file system status
• tree - Display a directory structure in a tree format (requires installation)
• xargs - Build and execute command lines from standard input

System Information

• uname -a - Display system information
• top - Display active processes
• htop - Interactive process viewer (requires installation)
• df -h - Show disk space usage
• free -h - Show memory usage
• uptime - Show how long the system has been running
• lscpu - Display CPU architecture information
• lsblk - List block devices
• dmesg - Show kernel ring buffer messages
• ps aux - Display all running processes
• whoami - Show the current user
• last - Show last logged in users
• cat /proc/cpuinfo - Display CPU information
• cat /proc/meminfo - Display memory information
• vmstat - Report information about processes, memory, paging, block I/O, traps, and CPU activity
• lsof - List open files and the processes that opened them
• uptime - Show system load averages and uptime
• hostname - Display the system's hostname

Package Management

• sudo apt update - Update package lists
• sudo apt upgrade - Upgrade installed packages
• sudo apt dist-upgrade - Upgrade packages, handling dependencies
• sudo apt install [package] - Install a package
• sudo apt remove [package] - Remove a package
• apt search [keyword] - Search for a package
• sudo apt autoremove - Remove unnecessary packages
• apt list --installed - List all installed packages
• apt show [package] - Display information about a package
• apt-cache policy [package] - Show package version information
• dpkg -l - List all installed packages using dpkg
• sudo apt purge [package] - Remove a package and its configuration files
• sudo apt-get clean - Clear local repository of retrieved package files
• sudo dpkg -i [package.deb] - Install a .deb package
• sudo apt-mark hold [package] - Prevent a package from being upgraded
• apt-file search [filename] - Search for a file in available packages (requires installation)
• sudo apt edit-sources - Edit the sources list for package management

User Management

• adduser [username] - Add a new user
• deluser [username] - Delete a user
• passwd [username] - Change a user's password
• groups [username] - List groups a user belongs to
• who - Show who is logged in
• last - Show last logged in users
• usermod -aG [group] [username] - Add a user to a group
• sudo su - [username] - Switch to another user
• finger [username] - Show information about a user
• chage -l [username] - Show password aging information
• sudo visudo - Edit the sudoers file
• userdel -r [username] - Delete a user and their home directory
• id [username] - Show user ID and group ID information
• newgrp [group] - Log in to a new group
• groups - List groups for the current user
• sudo usermod -d [new_home] [username] - Change a user’s home directory

Networking

• ifconfig - Display network interfaces (deprecated; use ip addr)
• ip addr - Show IP address and network details
• ping [host] - Check connectivity to a host
• curl [URL] - Transfer data from or to a server
• wget [URL] - Download files from the web
• netstat -tuln - Display listening ports
• traceroute [host] - Trace the route to a network host
• nslookup [domain] - Query DNS for a domain
• dig [domain] - Perform DNS lookup (requires installation)
• whois [domain] - Retrieve domain registration information
• ssh [user]@[host] - Securely connect to a remote server
• scp [file] [user]@[host]:[path] - Securely copy files to a remote server
• ftp [host] - Connect to an FTP server
• telnet [host] [port] - Connect to a host via Telnet (if installed)
• route -n - Display the routing table
• ip link show - Show all network interfaces
• nmap [host] - Network exploration tool and security/port scanner (requires installation)

Disk Management

• mount - List mounted filesystems
• umount [device] - Unmount a filesystem
• fdisk -l - List disk partitions
• df -i - Show inode usage
• du -h [directory] - Show directory size in human-readable format
• lsblk - List block devices with mount points
• badblocks [device] - Check for bad sectors on a disk
• fsck [device] - Check and repair a filesystem
• mkfs.ext4 [device] - Create an ext4 filesystem on a device
• resize2fs [device] - Resize an ext2/ext3/ext4 filesystem
• dd if=[source] of=[destination] - Copy and convert files (use with caution)
• parted [device] - Manage disk partitions interactively
• mount -o loop [file] [mountpoint] - Mount an image file
• pvcreate [device] - Initialize a physical volume for LVM
• vgcreate [volume-group] [device] - Create a volume group in LVM

Search and Find

• find [path] -name [filename] - Search for files by name
• grep [pattern] [file] - Search for a pattern in a file
• locate [filename] - Find files by name quickly
• which [command] - Show the full path of a command
• whereis [command] - Locate the binary, source, and manual page files
• history - Show command history
• echo [text] - Print text to the terminal
• sed 's/[old]/[new]/g' [file] - Replace text in a file
• awk '{print $1}' [file] - Print the first column of a file
• grep -r [pattern] [directory] - Recursively search for a pattern in a directory
• find [path] -type f -exec [command] {} \; - Execute a command on found files
• xargs - Build and execute command lines from standard input
• fuzzyfind [pattern] - Fuzzy search for files (requires installation)

Miscellaneous

• clear - Clear the terminal screen
• man [command] - Display the manual for a command
• alias [name]='[command]' - Create an alias for a command
• unalias [name] - Remove an alias
• exit - Exit the terminal session
• chmod [permissions] [file] - Change file permissions
• chown [user]:[group] [file] - Change file owner and group
• tar -cvf [archive.tar] [directory] - Create a tar archive
• tar -xvf [archive.tar] - Extract a tar archive
• zip [archive.zip] [file] - Create a zip archive
• unzip [archive.zip] - Extract a zip archive
• date - Display the current date and time
• cal - Display a calendar
• export [variable]=[value] - Set an environment variable
• env - Display environment variables
• echo $PATH - Display the current PATH variable
• crontab -e - Edit the cron jobs for the current user