Commands

The special characters “^” and “$” in combination can be used to retrieve words or sentences starting and at the same time ending with a specified character.

The killall command in Linux is used to kill multiple processes. It can kill the processes by their names and groups. killall command works with signals also

The iostat command in Linux displays the system’s resources being used. It can display the CPU or device/disk usage, resource usage report in real time.

The wall command in Linux allows the users to send broadcast messages to all the connected users or the group of users. Here wall command in Linux is discussed.

The “rm -rf” command in Linux is the combination of “-r” and the “-f” options that deletes the specified directory “recursively” and “forcefully”.

The “ls -ltr” lists the content of the specified directory in a (-l)long list format (-r)reversely which is sorted by its last modification date and time(-t).

Linux offers a pre-installed “whereis” command that retrieves the location of the binary, source code, and manual page files of the specified command.

To “capture groups” with the “sed” command line utility use the “capturing parentheses” “\(” “\)” that accesses the specific part of a file to edit it.

In Linux, the “sed” command removes the whitespaces from text files with the combination of its subcommands, supported options, and regular expressions.

The split is a Linux command line utility of Linux considered for breaking down large files into multiple small-size files. See the guide for more explanation.

The ss (Sockets Statistics) is the replacement of the netstat command, helpful for troubleshooting or resolving network-related issues.

In Linux, the “who” is the pre-installed command line utility that provides currently logged-in users along with their additional login information.

The make command allows the users to compile project source files. For compiling the source code, the set of instructions is defined in the “makefile” file.

The dig command is the popular command-line utility for networking administrators to obtain DNS-related information for domain names.

The nohup runs the task in the background without interruption, the disown deletes the background tasks while the ampersand(&) runs the task in the background.

The “-f(follow)” parameter of the “tail” command is mainly used by the system administrator for monitoring the text and log files in real-time.

In Linux, the “nc -l” command creates a simple network server by specifying the and . It is used to test network connectivity.

To match the exact string using the “grep” command, use the “grep -w “matching_string” ” command. It extracts the lines where the strings are matched.

Linux bash scripting uses the “set -x” and “set -v” commands to echo the defined set of shell commands placed in it at any point.

The “bg” places the foreground job in the background, and the “fg” resumes the background jobs. However, the “Ctrl+Z” key keeps the job in a “stopped” state.

In Linux, the sed Command: sed ‘s/\s\s*/ /g’ allows the users to replace more than one whitespace character or tab with a single whitespace globally.

In Linux, multiple edits with a single call to the sed command are performed on a string or a file by repeating the multiple sed patterns (single call to sed).

In Linux, the “arping” command sends ARP requests to the host by specifying the IP address and verifying the availability of hosts on a network.

To find duplicate files in the quickest way, use the “fdupes” command with the “r” option by specifying the directory name.

The “find” is the built-in command for finding files/directories based on their name, username, group, … Read More

The “lftp” command transfers or manages files in a remote machine by making a connection over protocols including UDP, HTTP, FTP, and many more.

To follow the redirect to the URL, execute the “curl -L ” command. Before it, users must ensure that the “curl” command is installed in the system.

To replace a “\n(newline)” to a “,(comma)” use the “sed” command “-z”, “H, h, d, x and y”, “-n, H, h, g, and p ”, “H, x, p”, and “a, b, $! and N” flags.

The sudo apt-get clean command is used to clean the cache memory, which will increase your system performance and reduce the risk of a system crash.

To output the binary representation of a hex number, execute the “echo -n “” | xxd -r -p | xxd -b” command in a Linux terminal.

To sort the output of the “ls” command by modification date use its “-t” argument, and also the “-l(list)” flag that displays the “date&time” of the file/directory.

To count the total number of occurrences of the specified word/pattern, use the “grep” command with the “wc(word count)” and “tr(translates)” options.

To instant search with the “less” command, use the “less ” script by specifying the in the Linux terminal.

The “find -name” locates the files/directories by different parameters name, extensions, or searching and deleting the particular file/directory.

To capture all the UDP packets using the tcpdump command, execute the “sudo tcpdump -i udp” command in a Linux terminal.

The “substr” function of the “awk” command searches for the specified character/pattern starting from the particular position to an optional length.

To decode the base64 string in Linux, you can use the echo statement with the pipe command or decode function, use the text file, or use the bash script.

In Linux, the tmux is the utility to create and manage terminal sessions such as attaching, detaching, or splitting the screen horizontally or vertically.

The “ps -ef | grep processname” command filters out a process from a list of running processes and displays information in the Linux system.

The “chmod +x” makes the file/directory executable for all users while the “chmod 755” sets various types of permissions to the users.

To run the getent command in Linux, follow the general syntax “getent [Options] [Database] [Key]”. It finds the information from the computer’s databases.

The passwd command is used by following the general syntax of the “passwd [Options] [User name]” to set and change the password of user accounts.

In Linux, the 6 best ways to view files are by using the commands, i.e., cat, more, less, nl, xdg-open, and text editors, i.e., nano.

The “ldd” command stands for “List Down Dependencies”, which is used to display executable files or program-shared library dependencies.

Linux offers the “echo “Body” | mailx -a attachment.pdf -s “Subject” [email protected]” command to send and receive email messages.

To use chown recursively, use the “R” flag with the command’s syntax. You can change the user, groups, and both (users and groups) in one command.

Linux offers the “sudo gpasswd -d ” command to remove a user from a group. You can also remove a user record from the “/etc/group” file.

Uncover the power of Linux’s “cmp” command. Compare files & verify integrity with ease. Learn basic usage, benefits, and scenarios to improve efficiency.

Learn how to use the powerful pkg-config command in Linux. Understand its syntax and how to find and manage software packages with ease.

Unlock the power of Linux logs with our guide on mastering the journalctl command. Learn to manage and diagnose system issues in no time efficiently.

The most widely used command line methods to list disk details and mounted file systems in Linux are lsblk, df, cfdisk, lshw, fdisk, hwinfo, and sfdisk.

Linux and most of its distributions support the network command line utility “ethtool” to display and manage the network interface devices.

Linux offers the “nice” commands to run a program with a modified scheduling priority and “renice” for an already-running process.

Linux offers the “reset”, “clear”, and “printf” commands to clear the terminal screen. The user can also use the “Ctrl+L” shortcut key to perform this task.

The xxd command can convert text into hexadecimal text, binary and reverse the hexadecimal to normal text as explained in this guide with different examples.

The important uses of the tcpdump command are explained, which can be very helpful for beginners to monitor the network communication with the tcpdump command.

The nmap command scans the IP addresses on Linux to get their information. We can scan the range of IP addresses with the nmap.

To list only directories recursively, use the “ls(list)”, “du(disk usage)”, “find”, and “tree” command. Read this post for more details.

The crontab offers the “MAILTO” parameter to set the mail address to send notifications. Once the job is executed, an email will be sent to the address.

GNU Debugger (GDB) acts as a compiler for various languages, i.e., C, and C++. Read out this post to get the list of GDB commands and their usage with examples.

The “who”, “w”, and “whoami” are the utilities for displaying the last boot, activities or average load, and currently logged-in user.

Linux offers the “tar” command with the “tvf” option to view the contents of a tar file. It displays the “file names”, “date and time”, and “file location”.

Linux offers the “lsusb” command to display a list of all USB devices connected to the system, including the device’s vendor ID, product ID, and device class.

Linux offers the “scp” command to copy/transfer files between remote systems. Also, you can copy a file from the local to a remote machine and vice versa.

The nmap provides advanced features to scan for vulnerabilities in a specific port, multiple ports, and the range of a port, as shown in the article.

Linux offers the “curl” command to make REST API requests to the server. Different HTTP methods, GET, POST, PUT and DELETE, are used to manage data.

In Linux, the user can use “rsync”, “pv”, ”tar” and the “dd” utility as an alternative to the cp command to show the progress bar and speed.

Linux provides a built-in command line tool “rmdir” command to remove the directories and subdirectories from the local system.