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