Essential Linux Commands Cheat Sheet for Beginners

Posted on Aug 30, 2024 in Computers

Linux Commands Cheat Sheet

Directory Navigation

  • ls = List files and directories in the current directory.

  • ls -a = List all files and directories, including hidden files.

  • ls -l = List files and directories in long format.

  • pwd = Show the present working directory.

  • cd [dir_path] = Change location to the specified directory.

  • cd ~ = Change directory to $HOME.

  • cd .. = Move up one directory level.

Files

  • mkdir [dir_name] = Create a new directory.

  • rm [file_name] = Remove a file.

  • rm -r [directory_name] = Remove a directory recursively.

  • cp [source_file] [destination_file] = Copy the contents of one file to another file.

  • mv [source_file] [destination_file] = Move or rename files or directories.

  • touch [file_name] = Create a new file.

  • cat [file_name] = Show the contents of a file.

  • cat [source_file] >> [destination_file] = Append file contents to another file.

  • nano [file_name] = Open or create a file using the Nano text editor.

  • vi [file_name], vim [file_name] = Open or create a file using the Vi/Vim text editor.

  • head [file_name] = Show the first ten lines of a file.

  • tail [file_name] = Show the last ten lines of a file.

Users and Groups

  • sudo useradd [user_name] = Create a new user account.

  • sudo userdel [user_name] = Delete a user account.

  • sudo usermod -aG [group_name] [user_name] = Modify user information (add a user to a group).

  • sudo passwd [user_name] = Change the current user’s or another user’s password.

  • sudo groupadd [group_name] = Add a new group.

  • sudo groupdel [group_name] = Delete a group.

  • sudo [command] = Temporarily elevate user privileges to superuser or root.

  • su - [user_name] = Switch the user account or become a superuser.

File Permissions

  • chmod 777 [file_name] = Assign read, write, and execute file permission to everyone (rwxrwxrwx).

  • chown [user_name] [file_name] = Change the ownership of a file.

  • chown [user_name]:[group_name] [file_name] = Change the owner and group ownership of a file.

  • chgrp [group_name] [file/directory] = Change file or directory group.

Processes

  • ps = List active processes.

  • top = See all running processes.

  • htop = Interactive and colorful process viewer.

  • kill [process_id] = Terminate a Linux process under a given ID.

  • killall [label] = Terminate all processes with a given label.

  • nohup [command] & = Run a Linux process in the background.

  • bg = List and resume stopped jobs in the background.

  • fg = Bring the most recently suspended job to the foreground.

  • fg [job] = Bring a particular job to the foreground.

System Management

  • uptime = Display how long the system has been running, including the load average.

  • hostname = View system hostname.

  • hostname -i = Show the IP address of the system.

  • date = See current date and time.

  • cal = Show current calendar (month and day).

  • whoami = See which user you are using.

Network

  • ifconfig = Display IP addresses of all network interfaces.

  • ping [remote_host] = Ping remote host.

  • netstat = Show network statistics.

  • nslookup [domain_name] = Receive information about an internet domain.

SSH Login

  • ssh [user_name]@[host] = Connect to a remote host as a user via SSH.

  • ssh [host] = Securely connect to a host via SSH default port 22.

  • ssh-keygen = Generate SSH key pairs.

  • scp [file_name] [user_name]@[host]:[remote_path] = Securely copy files between local and remote systems via SSH.

Disk Usage

  • df -h = Check free and used space on mounted systems.

  • mount = Show currently mounted file systems.

  • mount [device_path] [mount_point] = Mount a device.

File Transfer

  • scp [source_file] [user]@[remote_host]:[destination_path] = Copy a file to a server directory securely.

  • wget [link] = Download files from FTP or web servers.

  • curl [link] = Transfer data to or from a server.

File Compression

  • tar czf [archive.tar.gz] = Create a .gz compressed tar archive.

  • tar cf [archive.tar] [file/directory] = Archive an existing file or directory.

  • gzip [file_name], gunzip [file_name.gz] = Compress or decompress .gz files.

  • unzip [archive.zip] = Extract a zip archive.

Packages

Debian/Ubuntu

  • sudo apt update = Update package list.

  • sudo apt upgrade = Upgrade installed packages.

  • sudo apt install [package_name] = Install an APT package.

  • sudo apt remove [package_name] = Remove an APT package.

RedHat/CentOS/Fedora

  • sudo yum update = Update package list and upgrade them.

  • sudo yum install [package_name] = Install a package.

  • sudo yum remove [package_name] = Remove a package.

Searching

  • find [path] -name [search_pattern] = Find files and directories.

  • grep [search_pattern] [file_name] = Search for a specific pattern in a file.

  • grep -r [search_pattern] [directory_name] = Recursively search for a pattern in a directory.

  • grep -i [search_pattern] [file_name] = Case insensitive search.

  • locate [name] = Locate all files and directories related to a particular name.

  • awk '[search_pattern] {print $0}' [file_name] = Print all lines matching a pattern in a file.

  • sed 's/[old_text]/[new_text]/' [file_name] = Find and replace text in a specified file.

  • find [dir_name] -name [search_pattern] = Find files by name.

Service Management

  • systemctl start [service_name] = Start a service.

  • systemctl stop [service_name] = Stop a service.

  • systemctl restart [service_name] = Restart a service.

  • systemctl status [service_name] = Check service status.

  • systemctl enable [service_name] = Enable a service.

  • systemctl disable [service_name] = Disable a service.

Useful Shell Commands

  • man [command] = Display a built-in manual for a command.

  • history = Print the command history used in the terminal.

  • echo [text] = Display the text.

  • who = Show who is logged on.