This cheatsheet is a quick reference for common Linux commands on Ubuntu Server. It covers basic operations, system administration, networking, and more. Use it as a handy reference when working with Linux commands on Ubuntu Server.
pwd: Display the name of the current working directory.cd <directory>: Change the current working directory.ls: List the files and directories in the current working directory.
touch <file>: Create a new, empty file.rm <file>: Remove a file.rm -r <directory>: Remove a directory and all of its contents.cp <source> <destination>: Copy a file or directory.mv <source> <destination>: Move a file or directory.
cat <file>: Display the contents of a file.less <file>: Display the contents of a file one page at a time.
top: Display real-time information about the processes running on the system, including the CPU and memory usage of each process.ps: Display information about the processes running on the system.kill <pid>: Terminate the process with the specified process ID (PID).
apt update: Update the list of available packages and their versions.apt upgrade: Upgrade installed packages to their latest versions.apt install <package>: Install a new package.apt remove <package>: Remove an installed package.
nano <file>: Edit the specified file using the Nano text editor.vi <file>: Edit the specified file using the Vi text editor.
tar -cvf <archive>.tar <files>: Create a tar archive containing the specified files.tar -xvf <archive>.tar: Extract the files from a tar archive.gzip <file>: Compress a file using gzip.gunzip <file>.gz: Decompress a file that was compressed using gzip.
ifconfig: Display the network configuration for all network interfaces.ping <host>: Send a test packet to a network host to see if it is reachable.
uname -a: Display information about the current system, including the kernel version and machine hardware name.uptime: Display the amount of time that the system has been running.free -m: Display the amount of free and used memory in the system, in megabytes.df -h: Display the amount of free and used space on the system's disk drives, in human-readable format.
whoami: Display the current user's username.id: Display information about the current user, including the user's UID and primary group.groupadd <group>: Create a new group.useradd <user>: Create a new user.usermod -a -G <group> <user>: Add a user to a group.
chmod <permissions> <file>: Change the permissions of a file.chown <user>:<group> <file>: Change the owner and group of a file.
grep <pattern> <files>: Search for a pattern in one or more files.find <path> <expression>: Search for files matching a specified expression.
echo $<variable>: Display the value of an environment variable.export <variable>=<value>: Set the value of an environment variable.
bzip2 <file>: Compress a file using bzip2.bunzip2 <file>.bz2: Decompress a file that was compressed using bzip2.xz <file>: Compress a file using xz.unxz <file>.xz: Decompress a file that was compressed using xz.
lpr <file>: Print a file.lpq: Display the status of the print queue.
tail -f /var/log/syslog: Display the contents of the syslog in real time.
dd if=<input_file> of=<output_file>: Create an exact copy of a file.tar -czvf <archive>.tar.gz <files>: Create a tar archive and compress it with gzip.tar -czvf <archive>.tar.bz2 <files>: Create a tar archive and compress it with bzip2.
ssh <user>@<host>: Connect to a remote host using SSH.scp <source> <user>@<host>:<destination>: Copy a file to a remote host using SCP.
sort <file>: Sort the lines of a file.uniq <file>: Remove duplicate lines from a file.wc <file>: Count the number of lines, words, and characters in a file.
systemctl start <service>: Start a Systemd service.systemctl stop <service>: Stop a Systemd service.systemctl restart <service>: Restart a Systemd service.systemctl status <service>: Display the status of a Systemd service.
ip link: Display information about the system's network interfaces.ip addr: Display information about the system's network addresses.ip route: Display the system's routing table.ip neigh: Display the system's neighbor cache (i.e., the mapping of IP addresses to MAC addresses).
nice <command>: Run a command with a lower priority.renice <priority> -p <pid>: Change the priority of an existing process.
at <time>: Schedule a command to be executed at a specified time.crontab -e: Edit the current user's crontab file (used to schedule recurring tasks).
vmstat: Display information about the system's memory, processes, and swap space.mpstat: Display information about the system's processors.iostat: Display statistics about the system's input/output performance.sar: Collect and display system activity information.
cut -d <delimiter> -f <field> <file>: Extract a field from a file that is delimited by a specified character.sed 's/<pattern>/<replacement>/' <file>: Replace a pattern in a file with a specified string.
ssh-keygen: Generate a new SSH key pair.chpasswd: Change the password for a user.
uptime: Display the system's uptime (i.e., the amount of time it has been running).top: Display information about the processes running on the system, including the CPU and memory usage of each process.ps aux: Display a detailed list of processes running on the system.free -m: Display information about the system's memory usage, including the amount of free and used memory.iostat -x: Display extended statistics about the system's input/output performance.mpstat -P ALL: Display information about the utilization of each CPU on the system.sar -u: Collect and display information about the CPU utilization on the system.
dpkg -l: List the packages installed on the system.dpkg -L <package>: List the files installed by a package.update-alternatives --config <name>: Select a configuration for an alternative (i.e., a program that provides multiple versions of a command).
fsck <device>: Check a file system for errors and repair any that are found.tune2fs <device>: Modify the parameters of an ext2 or ext3 file system.mount: Display the currently mounted file systems.umount <device>: Unmount a file system.fdisk -l: Display the partition table for the system's disk drives.
alias <alias>='<command>': Create an alias for a command.history: Display a history of recently executed commands.cal: Display a calendar.nohup <command> &: Run a command in the background and allow it to continue running after the terminal is closed.tar -czvf <archive>.tar.xz <files>: Create a tar archive and compress it with xz.time <command>: Measure the amount of time it takes to run a command.whois <domain>: Look up information about a domain name.tee <file>: Redirect the output of a command to both the terminal and a file.watch <command>: Execute a command repeatedly and display the output.which <command>: Display the path of the executable file associated with a command.time <command>: Measure the amount of time it takes to run a command.