home: references: linux
cat - displays the contents of a file.cd - changes the current directory.cp - copies files and directories.ls - lists files and directories in the current directory.mkdir - creates a new directory.more and less - allow you to view the contents of a file one screen at a time.mv - moves or renames files and directories.rm - removes files and directories.rmdir - removes an empty directory.touch - creates a new empty file or updates the timestamp of an existing file.awk - processes text files by performing operations on individual fields.cat - concatenates files and displays the contents of a file.cut - extracts sections of text from a file.echo - displays a line of text or the value of a variable.grep - searches for text patterns in a file.head - displays the first few lines of a file.sed - processes text files by performing text transformations.sort - sorts lines of text in a file.tail - displays the last few lines of a file.tr - translates or deletes characters in a file.free - displays the total amount of free and used memory in the system.lsof - lists all the open files in the system and displays memory usage for each open file.pmap - provides detailed information about the memory usage of a particular process.ps - displays the processes running in the system along with their process ID, CPU and memory usage.sar - collects and reports on system resource usage, including memory usage.smem - reports on the memory usage of individual processes and memory usage by user.top - provides real-time dynamic view of the processes running in the system, their CPU usage and memory usage.vmstat - reports on the virtual memory statistics of the system, including memory usage, paging and
swapping.curl - transfers data from or to a server, using various protocols such as HTTP, FTP, and more.dig - queries DNS servers for information about domain names and IP addresses.ifconfig - displays network interface configuration information, such as IP addresses and network masks.ip - used to show or manipulate routing, devices, policy routing and tunnels.netcat - reads and writes data across network connections using TCP or UDP protocols.netstat - displays information about active network connections and their status.nmap - scans for open ports on a network host.ping - sends ICMP echo request packets to a host to test if it's reachable and measure the response time.traceroute - shows the path packets take from the local host to a remote host, as well as the response time for each hop.ssh - connects to a remote host securely using the SSH protocol for remote shell access or file transfer.apt - Advanced Package Tool, used to manage packages on Debian-based distributions.dnf - Dandified YUM, used to manage packages on Fedora-based distributions.dpkg - Debian Package, used to install, remove, and manage Debian packages.pacman - Package Manager, used to manage packages on Arch Linux and its derivatives.pip - Package Installer for Python, used to install and manage Python packages.rpm - Red Hat Package Manager, used to install, remove, and manage RPM packages.snap - Snapcraft, used to manage Snap packages on Ubuntu and other distributions.sudo - Superuser Do, used to run commands with elevated privileges.yum - Yellowdog Updater Modified, used to manage packages on CentOS and other Red Hat-based distributions.zypper - Zypper Package Manager, used to manage packages on openSUSE and SUSE Linux Enterprise.chmod - changes the file or directory permissions.chown - changes the owner of a file or directory.groups - displays the groups to which a user belongs.passwd - changes a user's password.su - switches to another user account.sudo - runs a command with administrative privileges.umask - sets the default permissions for new files and directories.useradd - creates a new user account.userdel - deletes a user account.visudo - edits the sudo configuration file.kill - sends a signal to terminate a process.killall - sends a signal to terminate all processes with a given name.nice - adjusts the priority of a process.pgrep - finds processes based on their name or other attributes.pidof - finds the process ID of a running program.ps - reports on the processes running in the system.pstree - displays a tree-like diagram of all processes running in the system.renice - changes the priority of a running process.top - provides a real-time dynamic view of the processes running in the system.uptime - displays how long the system has been running and the average system load over the last 1, 5, and 15 minutes.awk - a text processing tool that searches for and manipulates text patterns.bash - the default shell in most Linux distributions and a popular choice for writing shell scripts.chmod - changes the permissions of files and directories.echo - displays a message or the value of a variable on the terminal.grep - searches for a pattern in a file or stream of text.sed - a text processing tool that performs string manipulations and transformations.sh - the original Bourne shell and a basic but still widely-used shell.source - reads and executes the content of a file in the current shell session.test or [ ] - evaluates an expression and returns a Boolean result.while - a loop that executes a set of commands while a condition is true.chmod - changes the permissions of a file or directory.chown - changes the owner or group of a file or directory.df - displays the amount of disk space used and available on the file system.free - displays the amount of free and used memory in the system.kill - terminates a running process by sending a signal to its process ID.ps - displays the processes running in the system along with their process ID, CPU, and memory usage.reboot - restarts the system.shutdown - shuts down the system.sudo - executes a command with elevated privileges.systemctl - controls system services and processes.df - displays information about the disk space usage of mounted file systems.free - displays information about the amount of free and used memory in the system.hostname - displays the name of the current host.ifconfig - displays network interface configuration information.lscpu - displays information about the CPU architecture and processing units.lsblk - displays information about the available block devices, such as hard drives and USB drives.ps - displays information about the current processes running on the system.top - displays information about the processes running on the system in real-time.uname - displays information about the system kernel.uptime - displays the current uptime of the system.chown - changes the ownership of a file or directory.groupadd - creates a new group.groupdel - deletes a group.groupmod - modifies a group.passwd - changes a user's password.useradd - creates a new user account.userdel - deletes a user account.usermod - modifies a user account.id - displays the user and group IDs of a user.su - allows a user to switch to another user account or to become the root user.