Linux-cheat-sheet

System Information Commands

Command	Description
uname	Displays the system information. It provides details about the kernel, operating system, and machine architecture. Commonly used options include: -a - Displays all system information. -r - Shows the kernel release. -m - Prints the machine hardware name. -o - Shows the operating system name.
hostname	Prints the name of the current host system. It displays the hostname that has been set for the system.
uptime	Shows how long the system has been running, as well as the average system load over different time periods.
whoami	Displays the current username. It shows the username associated with the current user session.
w	Displays who is logged in and what they are doing. It provides a summary of currently logged-in users, their activities, and system load.
who	Lists currently logged-in users. It shows information about the users who are currently logged into the system.
id	Prints user and group information. It displays the user and group IDs associated with the current user session.
last	Shows a listing of last logged-in users. It provides information about previous login sessions, including login time and duration.
date	Displays the current date and time. It can also be used to set the system date and time.
cal	Displays a calendar for a specific month or year. It shows a calendar for the current month by default. Commonly used options include: -y - Displays a calendar for the current year. -j - Shows Julian day numbers.
hwinfo	Displays detailed hardware information. It provides comprehensive information about system hardware, including CPU, memory, disk, and network devices.
lshw	Lists hardware information. It displays detailed information about hardware components on the system.
lsblk	Lists block devices. It shows information about block devices such as hard drives and partitions.
fdisk	Manipulates disk partition table. It is used for disk partitioning tasks, including creating, deleting, and resizing partitions.
blkid	Prints block device attributes. It displays information about block devices, such as UUIDs and file system types.
df	Reports file system disk space usage. It shows the amount of disk space used and available on mounted file systems. Commonly used options include: -h - Prints sizes in human-readable format. -T - Shows the file system type.
du	Displays disk usage of files and directories. It calculates the sizes of files and directories and can be used to find out which directories consume the most disk space. Commonly used options include: -h - Prints sizes in human-readable format. -s - Displays only the total size.
free	Displays memory usage. It shows the amount of free and used memory on the system. Commonly used options include: -h - Prints sizes in human-readable format. -m - Displays sizes in megabytes.
ps	Lists running processes. It provides information about the currently running processes on the system. Commonly used options include: -e - Displays information about all processes. -f - Shows full-format listing. -aux - Provides a comprehensive listing of all processes, including those of other users.
top	Displays real-time system information. It shows a dynamic view of system processes, CPU usage, memory usage, and other system metrics.
htop	Interactive process viewer. It is an alternative to top and provides an interactive and colorful display of system processes and resource usage.
systemctl	Controls the system's systemd service manager. It is used to manage services, including starting, stopping, enabling, and disabling them. Commonly used options include: start - Starts a service. stop - Stops a service. status - Shows the status of a service. enable - Enables a service to start on boot. disable - Disables a service from starting on boot.
journalctl	Views and manages systemd journal logs. It allows you to query and view logs generated by the systemd journal. Commonly used options include: -u - Filters logs by a specific unit (service). -f - Displays logs in real-time. -n - Shows the specified number of recent logs.
dmesg	Prints kernel ring buffer messages. It displays the kernel's log messages, including information about hardware, drivers, and system events.
lsmod	Lists loaded kernel modules. It shows a list of currently loaded kernel modules (drivers) on the system.
uname -r	Shows the kernel release version. It prints the version of the Linux kernel running on the system.
lsusb	Lists USB devices. It displays information about connected USB devices, including their vendor and product IDs.
lspci	Lists PCI devices. It shows information about PCI devices connected to the system, such as network adapters and graphics cards.
lsdev	Lists devices on the system. It provides information about various devices connected to the system, including USB, PCI, and SCSI devices.
lsb_release	Prints LSB (Linux Standard Base) information. It displays information about the Linux distribution and version being used.
cat /etc/os-release	Prints information from the /etc/os-release file. It shows details about the Linux distribution, including the name, version, and ID.
lsmod	Lists loaded kernel modules. It shows a list of currently loaded kernel modules (drivers) on the system.
lsb_release -a	Shows LSB (Linux Standard Base) information. It provides comprehensive information about the Linux distribution, including distributor ID, description, release, and codename.
ls -l /proc	Lists process-related information in the /proc directory. It provides access to various system and process-related information through virtual files in the /proc directory.
ps -eo pid,ppid,cmd,%mem,%cpu	Custom process listing. It lists running processes with specific details such as process ID, parent process ID, command, memory usage, and CPU usage percentage.
users	Shows a list of currently logged-in users. It provides a simple list of currently logged-in user names.
finger	Displays information about user accounts. It shows detailed information about user accounts, including login time, idle time, and full name.

File Operations Commands

File Navigation and Listing

Command	Description
ls	Lists files and directories in the current directory. Commonly used options include: -l - Displays detailed information, including permissions and file sizes. -a - Shows hidden files. -h - Prints sizes in human-readable format.
cd	Changes the current directory. It allows you to navigate to different directories within the file system.
pwd	Prints the current working directory. It displays the full path of the current working directory.
tree	Displays the directory structure as a tree. It shows a hierarchical tree view of directories and their contents. Commonly used options include: -L - Limits the depth of the tree. -a - Shows hidden files. -d - Displays directories only.

File Manipulation

Command	Description
cp	Copies files and directories. It duplicates files or directories from a source location to a destination location. Commonly used options include: -r - Copies directories recursively. -i - Prompts for confirmation before overwriting existing files. -p - Preserves file attributes and permissions.
mv	Moves or renames files and directories. It can be used to move files to a different location or rename them within the same directory.
rm	Removes files and directories. It is used to delete files and directories permanently. Commonly used options include: -r - Removes directories recursively. -f - Forces removal without prompting for confirmation. -i - Prompts for confirmation before deleting each file.
touch	Creates an empty file or updates the access and modification timestamps of an existing file. It is commonly used to create placeholder files.
cat	Concatenates and displays file content. It is used to view the contents of a file or combine multiple files into a single file.
head	Displays the first few lines of a file. It is commonly used to preview the beginning of a large file. Commonly used options include: -n - Specifies the number of lines to display.
tail	Displays the last few lines of a file. It is commonly used to view log files or monitor real-time changes. Commonly used options include: -n - Specifies the number of lines to display. -f - Follows the file and displays appended data as it grows.
more	Displays file content one screen at a time. It allows you to scroll through the contents of a file. Press the spacebar to scroll down or press 'q' to exit.
less	Displays file content interactively. It provides advanced features like backward scrolling and searching within the file. Press the spacebar or 'f' to scroll down and 'b' to scroll up. Press 'q' to exit.
nano	Opens a text editor to create or edit files. It is a simple and user-friendly command-line text editor. Commonly used options include: -w - Disables word-wrapping. -r - Recovers unsaved changes from a crashed session.
vi or vim	Opens the Vim text editor. It is a powerful and widely-used text editor with extensive features and customization options.
chmod	Changes file permissions. It allows you to modify the permissions (read, write, execute) for files and directories. Commonly used options include: u - User permissions. g - Group permissions. o - Other (everyone else) permissions. + - Adds permissions. - - Removes permissions.
chown	Changes file ownership. It is used to modify the owner and group of files and directories. Commonly used options include: -R - Applies changes recursively. user:group - Specifies the new owner and group.
chgrp	Changes file group ownership. It is used to modify the group ownership of files and directories. Commonly used options include: -R - Applies changes recursively. group - Specifies the new group.
ln	Creates links between files. It can create hard links or symbolic links (symlinks) to files and directories. Commonly used options include: -s - Creates symbolic links (symlinks). -f - Forces the creation of links, overwriting existing ones. -n - Creates links even if the target does not exist.
find	Searches for files and directories based on various criteria. It allows you to search for files based on their name, type, size, or other attributes. Commonly used options include: -name - Searches for files matching a specific name. -type - Filters files based on their type (regular file, directory, symbolic link, etc.). -size - Searches for files based on their size. -exec - Executes a command on the found files.
grep	Searches for patterns in files. It is used to search for specific strings or patterns within files. Commonly used options include: -i - Ignores case sensitivity. -r - Searches recursively in directories. -l - Lists only the filenames containing the pattern. -v - Inverts the matching, displaying non-matching lines.
file	Determines file type. It identifies the type of a file by examining its content and metadata.
stat	Displays file or file system status. It provides detailed information about a file or file system, including access permissions, size, timestamps, and more.
du	Displays disk usage of files and directories. It calculates the sizes of files and directories and can be used to find out which directories consume the most disk space. Commonly used options include: -h - Prints sizes in human-readable format. -s - Displays only the total size. -c - Shows a grand total at the end.
df	Reports file system disk space usage. It shows the amount of disk space used and available on mounted file systems. Commonly used options include: -h - Prints sizes in human-readable format. -T - Shows the file system type. -i - Displays inode information.
ln	Creates links between files. It can create hard links or symbolic links (symlinks) to files and directories. Commonly used options include: -s - Creates symbolic links (symlinks). -f - Forces the creation of links, overwriting existing ones. -n - Creates links even if the target does not exist.
tar	Archives and extracts files. It is used to create compressed or uncompressed archive files, commonly known as "tarballs". Commonly used options include: -c - Creates a new archive. -x - Extracts files from an archive. -v - Shows verbose output. -z - Compresses or decompresses using gzip. -f - Specifies the archive file name.
gzip	Compresses files using gzip compression. It is commonly used to reduce the size of files and save disk space. The compressed files have the extension .gz.
gunzip	Decompresses files compressed with gzip. It restores the original file from a compressed file.
zip	Compresses files into a ZIP archive. It is used to create compressed archives that can be easily shared or transferred.
unzip	Extracts files from a ZIP archive. It decompresses the contents of a ZIP file and restores the original files.
dd	Copies and converts files. It is used for low-level copying of data, creating disk images, or converting file formats. Be cautious when using this command, as it can overwrite data if used incorrectly.
split	Splits a file into multiple smaller files. It is useful for breaking down large files into manageable parts for storage or transfer. Commonly used options include: -b - Specifies the size of each split file. -l - Splits the file based on the number of lines. -a - Sets the number of digits in the split file names.
md5sum	Calculates and verifies MD5 checksums. It computes the MD5 hash value of a file and can be used to verify the integrity of downloaded files.
sha256sum	Calculates and verifies SHA-256 checksums. It computes the SHA-256 hash value of a file and is commonly used to ensure file integrity.
mount	Mounts a file system. It attaches a file system, such as a hard drive or a network share, to a specified directory in the file system hierarchy.
umount	Unmounts a file system. It detaches a mounted file system from the file system hierarchy.
fdisk	Manipulates disk partition tables. It is used for disk partitioning tasks, including creating, deleting, and resizing partitions.
parted	Manipulates disk partitions. It is a more advanced disk partitioning tool with additional features compared to fdisk.
mkfs	Creates a file system on a partition. It is used to format a partition with a specific file system type, such as ext4, NTFS, or FAT32.
fsck	Checks and repairs a file system. It scans and repairs inconsistencies in a file system, ensuring its integrity.
mount -o remount	Remounts a file system with different options. It allows you to change the mount options of a currently mounted file system.
find	Searches for files and directories based on various criteria. It allows you to search for files based on their name, type, size, or other attributes. Commonly used options include: -name - Searches for files matching a specific name. -type - Filters files based on their type (regular file, directory, symbolic link, etc.). -size - Searches for files based on their size. -exec - Executes a command on the found files.
grep	Searches for patterns in files. It is used to search for specific strings or patterns within files. Commonly used options include: -i - Ignores case sensitivity. -r - Searches recursively in directories. -l - Lists only the filenames containing the pattern. -v - Inverts the matching, displaying non-matching lines.
diff	Compares files line by line. It shows the differences between two files, highlighting added, removed, or modified lines. Commonly used options include: -u - Produces a unified diff format. -r - Performs a recursive comparison of directories. -q - Only reports if the files are different or identical. -c - Provides context lines around the differences.
scp	Copies files securely between hosts. It allows you to securely transfer files between local and remote systems using the SSH protocol.
rsync	Efficiently synchronizes files and directories. It is used for remote or local file synchronization, incremental backups, and mirroring.
wget	Downloads files from the web. It retrieves files from web servers using HTTP, HTTPS, or FTP protocols.
curl	Transfers data using various protocols. It is a versatile command-line tool for making HTTP, HTTPS, FTP, and other network requests.
quota	Manages disk quotas for users and groups. It allows you to set limits on disk usage for individual users or groups.
ln -s	Creates symbolic links (symlinks). It creates a shortcut or reference to a file or directory, pointing to its original location.

Process Management Commands

Process Monitoring and Information

Command	Description
ps	Lists running processes. It provides information about the currently running processes on the system. Commonly used options include: -e - Displays information about all processes. -f - Shows full-format listing. -aux - Provides a comprehensive listing of all processes, including those of other users.
top	Displays real-time system information. It shows a dynamic view of system processes, CPU usage, memory usage, and other system metrics.
htop	Interactive process viewer. It is an alternative to top and provides an interactive and colorful display of system processes and resource usage.
pstree	Displays a tree view of running processes. It shows the hierarchy of processes, illustrating parent-child relationships.
pgrep	Searches for processes by name or attributes. It allows you to find processes based on their name, process ID (PID), or other attributes.
pkill	Terminates processes based on name or attributes. It sends a signal to one or more processes, terminating them based on their name or attributes.
kill	Sends a signal to terminate a process. It allows you to send specific signals to a process, such as SIGTERM for graceful termination or SIGKILL for forceful termination.
killall	Terminates processes by name. It sends a signal to terminate all processes matching a specific name. Be cautious when using this command.
pgrep, pkill, kill, killall with signal number	Terminates processes with a specific signal. You can use these commands with a signal number to send a specific signal to a process. For example, SIGTERM (15) for graceful termination or SIGKILL (9) for forceful termination.
renice	Changes the priority of running processes. It allows you to adjust the scheduling priority of one or more processes, influencing their CPU usage.

Process Control and Manipulation

Command	Description
nohup	Runs a command that ignores hangup signals. It allows a command to continue running even after you log out or close the terminal.
bg	Puts a process in the background. It resumes a suspended or stopped process in the background, allowing it to continue running while you work on other tasks.
fg	Brings a background process to the foreground. It moves a background process to the foreground, allowing you to interact with it and see its output.
jobs	Lists background processes. It shows the status of background processes and their job IDs.
disown	Removes a process from the shell's job control. It detaches a process from the current shell, preventing it from receiving signals and exiting when the shell terminates.
ps -p	Displays information about specific processes. You can use this command with the PID (process ID) to retrieve detailed information about a specific process.
pstree -p	Displays process hierarchy with PIDs. It shows the hierarchy of processes along with their PIDs, illustrating parent-child relationships.
kill -l	Lists available signal names and numbers. It displays a list of signal names and their corresponding numbers, which can be used with the kill command.
nice	Runs a command with a modified scheduling priority. It allows you to adjust the priority of a command to influence its CPU usage and execution time.
ionice	Sets or gets the I/O scheduling class and priority of a process. It is used to control the I/O priority of a process, ensuring fair disk access among multiple processes.
lsof	Lists open files and processes. It displays information about files opened by processes, including the process ID (PID), file descriptors, and more.
fuser	Identifies processes using files or sockets. It helps you find processes that are using a specific file or socket.
strace	Traces system calls and signals of a running process. It allows you to monitor and analyze the interactions between a process and the operating system.
watch	Repeatedly runs a command and displays its output. It executes a command at regular intervals and shows the updated output, allowing you to monitor changes over time.
uptime	Shows how long the system has been running and the system load average. It provides information about the system's uptime, load average, and the number of logged-in users.
systemctl	Controls the system's systemd service manager. It is used to manage services, including starting, stopping, enabling, and disabling them. Commonly used options include: start - Starts a service. stop - Stops a service. status - Shows the status of a service. enable - Enables a service to start on boot. disable - Disables a service from starting on boot.
journalctl	Views and manages systemd journal logs. It allows you to query and view logs generated by the systemd journal. Commonly used options include: -u - Filters logs by a specific unit (service). -f - Displays logs in real-time. -n - Shows the specified number of recent logs.
systemd-analyze	Analyzes system boot-up performance. It provides information about the time taken by different units during the system boot process. Commonly used options include: blame - Lists units and their boot time in descending order. critical-chain - Shows the critical chain of units required for system boot.
at	Schedules commands to be executed at a specified time. It allows you to schedule one-time or recurring tasks to be executed in the future.
crontab	Manages cron jobs for scheduled task execution. It allows you to create, modify, or remove cron jobs that run commands at specific intervals.

Networking Commands

Network Configuration

Command	Description
ifconfig	Configures and displays network interfaces. It provides information about network interfaces and allows you to configure their IP addresses, netmasks, and more.
ip	Manages network interfaces and routing tables. It is a powerful tool for configuring network settings, including IP addresses, routes, and network namespaces.
iwconfig	Configures wireless network interfaces. It allows you to configure wireless network interfaces, including SSID, encryption, and transmit power.
route	Manages IP routing table. It allows you to view and modify the IP routing table, which determines the path for network packets.
netstat	Displays network statistics and connections. It provides information about network connections, routing tables, and network interface statistics.
ss	Displays socket statistics. It shows detailed information about network sockets, including listening ports, established connections, and more.
nmcli	Controls NetworkManager from the command line. It is used to manage network connections and settings through the NetworkManager service.
hostname	Displays or sets the system's hostname. It shows the hostname of the system or allows you to set a new hostname.
dnsdomainname	Shows the system's DNS domain name. It displays the DNS domain name configured for the system.
domainname	Shows or sets the system's NIS/YP domain name. It displays the NIS/YP domain name or allows you to set a new domain name.
netplan	Manages network configuration using Netplan. It is used to configure network interfaces and settings in systems that use Netplan as the network configuration tool.

Network Connectivity

Command	Description
ping	Sends ICMP Echo Request packets to a host. It is used to check network connectivity and measure round-trip time (RTT) to a destination host.
traceroute	Traces the route taken by packets to a destination. It shows the path packets take to reach a destination host, displaying the IP addresses of intermediate hops.
mtr	Combines ping and traceroute functionality. It provides a continuous stream of ping and traceroute data to monitor network connectivity and measure network latency.
nslookup	Queries DNS servers for DNS-related information. It allows you to retrieve information about domain names, IP addresses, and other DNS records.
host	Performs DNS lookups. It translates hostnames to IP addresses and vice versa using DNS.
dig	Performs DNS lookups and displays detailed DNS information. It is a flexible tool for querying DNS servers and retrieving various DNS records.
arp	Displays or modifies the ARP cache. It shows the IP-to-MAC address mappings in the ARP cache or allows you to manually add or remove entries.
ip neigh	Manages the neighbor table (ARP and NDISC cache). It displays and manipulates the neighbor table, which maps IP addresses to MAC addresses.
iptables	Manages firewall rules. It allows you to configure and manage firewall rules, including filtering, network address translation (NAT), and packet mangling.
firewalld	Manages firewall rules using firewalld. It provides a dynamically-managed firewall solution and allows you to configure and manage firewall rules through the firewalld service.
nc	Netcat utility for TCP/IP networking. It is a versatile tool for network debugging and data transfer, allowing you to create connections, listen on ports, and send or receive data.
	ssh
scp	Securely copies files between hosts. It allows you to securely transfer files between local and remote systems using the SSH protocol.
sftp	Securely transfers files between hosts. It provides a secure alternative to FTP, allowing you to transfer files between local and remote systems over SSH.
wget	Downloads files from the web. It retrieves files from web servers using HTTP, HTTPS, or FTP protocols.
curl	Transfers data using various protocols. It is a versatile command-line tool for making HTTP, HTTPS, FTP, and other network requests.
tcpdump	Captures and analyzes network traffic. It captures network packets in real-time and allows you to analyze network protocols and troubleshoot network issues.
wireshark	Graphical network protocol analyzer. It provides a graphical interface to capture, analyze, and dissect network packets in detail.
ifup	Activates a network interface. It brings a network interface up, enabling network connectivity.
ifdown	Deactivates a network interface. It brings a network interface down, disabling network connectivity.
ip link	Manages network interfaces. It displays and manipulates network interfaces, including creating, configuring, and deleting them.
ip addr	Manages IP addresses. It displays and manipulates IP addresses assigned to network interfaces, including adding, deleting, or modifying them.
ip route	Manages routing table entries. It displays and manipulates the IP routing table, allowing you to configure routing paths for network packets.
ip tunnel	Manages IP tunnels. It creates and manages IP tunnels for encapsulating network packets and routing them over other networks.
ethtool	Displays or modifies Ethernet device settings. It provides detailed information about Ethernet devices and allows you to configure their parameters.
ifstat	Displays interface statistics. It shows network interface statistics, including incoming and outgoing traffic rates, packets, and errors.
mii-tool	Displays or modifies Ethernet device settings. It provides information about and allows you to manipulate Ethernet device settings using the MII (Media Independent Interface).
netcat	Reads from and writes to network connections. It is a versatile networking tool that allows you to establish connections, send and receive data, and listen on ports.
iptables	Manages firewall rules. It allows you to configure and manage firewall rules, including filtering, network address translation (NAT), and packet mangling.
firewalld	Manages firewall rules using firewalld. It provides a dynamically-managed firewall solution and allows you to configure and manage firewall rules through the firewalld service.
ipset	Manages IP sets. It is used to manage sets of IP addresses, ports, or other network identifiers, allowing efficient filtering and matching of network traffic.
nmap	Network exploration and security auditing. It is a powerful tool for network scanning, port scanning, and detecting vulnerabilities in network hosts.
tcpdump	Captures and analyzes network traffic. It captures network packets in real-time and allows you to analyze network protocols and troubleshoot network issues.
ngrep	Network grep. It allows you to search for patterns in network traffic and capture packets that match specific criteria.
dstat	Displays system resource usage and statistics. It provides real-time monitoring of various system resources, including CPU, memory, disk, network, and more.
iftop	Displays bandwidth usage on an interface. It shows real-time network bandwidth usage on a specific network interface.
bmon	Monitors network bandwidth usage. It displays real-time network bandwidth usage for multiple interfaces in a graphical format.
nload	Monitors network traffic and bandwidth usage. It shows real-time network traffic and bandwidth usage in a graphical format.
iptraf-ng	Interactive network monitoring tool. It provides a variety of network monitoring features, including real-time traffic analysis, connections monitoring, and more.
wireshark	Graphical network protocol analyzer. It provides a graphical interface to capture, analyze, and dissect network packets in detail.
ss	Displays socket statistics. It shows detailed information about network sockets, including listening ports, established connections, and more.
netstat	Displays network statistics and connections. It provides information about network connections, routing tables, and network interface statistics.
arp	Displays or modifies the ARP cache. It shows the IP-to-MAC address mappings in the ARP cache or allows you to manually add or remove entries.
ip neigh	Manages the neighbor table (ARP and NDISC cache). It displays and manipulates the neighbor table, which maps IP addresses to MAC addresses.
traceroute	Traces the route taken by packets to a destination. It shows the path packets take to reach a destination host, displaying the IP addresses of intermediate hops.
mtr	Combines ping and traceroute functionality. It provides a continuous stream of ping and traceroute data to monitor network connectivity and measure network latency.
dig	Performs DNS lookups and displays detailed DNS information. It is a flexible tool for querying DNS servers and retrieving various DNS records.
nslookup	Queries DNS servers for DNS-related information. It allows you to retrieve information about domain names, IP addresses, and other DNS records.
host	Performs DNS lookups. It translates hostnames to IP addresses and vice versa using DNS.
wget	Downloads files from the web. It retrieves files from web servers using HTTP, HTTPS, or FTP protocols.
curl	Transfers data using various protocols. It is a versatile command-line tool for making HTTP, HTTPS, FTP, and other network requests.
ssh	Secure shell client for remote login. It provides secure remote access to a remote system using the SSH protocol.
scp	Securely copies files between hosts. It allows you to securely transfer files between local and remote systems using the SSH protocol.
sftp	Securely transfers files between hosts. It provides a secure alternative to FTP, allowing you to transfer files between local and remote systems over SSH.
telnet	Establishes a Telnet connection to a remote host. It allows you to interact with remote systems using the Telnet protocol.
nc	Netcat utility for TCP/IP networking. It is a versatile tool for network debugging and data transfer, allowing you to create connections, listen on ports, and send or receive data.
netcat	Reads from and writes to network connections. It is a versatile networking tool that allows you to establish connections, send and receive data, and listen on ports.
iptables	Manages firewall rules. It allows you to configure and manage firewall rules, including filtering, network address translation (NAT), and packet mangling.
firewalld	Manages firewall rules using firewalld. It provides a dynamically-managed firewall solution and allows you to configure and manage firewall rules through the firewalld service.
ipset	Manages IP sets. It is used to manage sets of IP addresses, ports, or other network identifiers, allowing efficient filtering and matching of network traffic.
nmap	Network exploration and security auditing. It is a powerful tool for network scanning, port scanning, and detecting vulnerabilities in network hosts.
curl	Transfers data using various protocols. It is a versatile command-line tool for making HTTP, HTTPS, FTP, and other network requests.
wget	Downloads files from the web. It retrieves files from web servers using HTTP, HTTPS, or FTP protocols.
ssh	Secure shell client for remote login. It provides secure remote access to a remote system using the SSH protocol.
scp	Securely copies files between hosts. It allows you to securely transfer files between local and remote systems using the SSH protocol.
sftp	Securely transfers files between hosts. It provides a secure alternative to FTP, allowing you to transfer files between local and remote systems over SSH.
ftp	Transfers files to and from remote systems. It allows you to connect to FTP servers and perform file transfer operations.
rsync	Efficiently synchronizes files and directories. It is used for remote or local file synchronization, incremental backups, and mirroring.
dig	Performs DNS lookups and displays detailed DNS information. It is a flexible tool for querying DNS servers and retrieving various DNS records.
nslookup	Queries DNS servers for DNS-related information. It allows you to retrieve information about domain names, IP addresses, and other DNS records.
host	Performs DNS lookups. It translates hostnames to IP addresses and vice versa using DNS.
whois	Retrieves domain registration information. It allows you to query WHOIS databases to retrieve information about domain names, including ownership, registration dates, and contact details.
tcpdump	Captures and analyzes network traffic. It captures network packets in real-time and allows you to analyze network protocols and troubleshoot network issues.
tshark	Command-line version of Wireshark. It captures and analyzes network packets from the command line, providing detailed protocol-level information.
ngrep	Network grep. It allows you to search for patterns in network traffic and capture packets that match specific criteria.
ssh-keygen	Generates SSH key pairs. It is used to generate SSH public and private key pairs for secure authentication and encrypted communication.
ssh-copy-id	Installs SSH keys on remote servers. It copies the local SSH public key to