kill
The kill command in Linux is used to terminate processes by sending specific signals to them. By default, it sends the SIGTERM signal (signal 15), which requests the process to stop gracefully. If a process doesn’t respond to SIGTERM, you can use SIGKILL (signal 9) to force immediate termination. Example commands: Kills the process with […]
df
The df command in Linux displays information about file systems, showing details such as mounted filesystems, their sizes, used space, available space, and usage percentages. It’s a versatile tool for checking disk space and can be customized with various options. Command examples: Display all mounted filesystems. Show inode information instead of disk blocks. Output sizes […]
alias
The alias command in Linux allows you to create shortcuts for frequently used commands or sequences of commands. This is particularly useful for streamlining your workflow by making complex or lengthy commands easier to execute with a simple name. Examples This example creates an alias ls that shows colored file listings, enhancing readability. The alias […]
sudo
The sudo command in Linux is used to execute a command with the privileges of another user, typically the root user. It allows you to perform administrative tasks that require elevated permissions. When you use sudo, it prompts you for your password (if needed) and temporarily grants you access to perform the task as if […]
apt
The apt command is a powerful tool used for managing packages in Ubuntu and other Debian-based Linux distributions. It simplifies tasks like installing, updating, and removing software by interacting with package repositories, making it more user-friendly than older tools like dpkg. Example Commands: This command updates the package list and upgrades all installed packages to […]
passwd
The passwd command in Linux is used to change user passwords. When run without arguments, it prompts the user for their current password and then allows them to set a new one. System administrators can use sudo passwd username to reset another user’s password. The command also offers options like -d to remove a password, […]
ps
The ps command in Linux is used to view information about running processes. It displays details such as the process ID (PID), user, CPU usage, memory usage, and the command executed. This command is essential for system monitoring and management. Example Commands: This command shows a basic list of running processes, including PID, USER, CPU%, […]
grep
The grep command in Linux is a powerful tool for searching text patterns within files. It allows users to specify a pattern, such as a word or phrase, and efficiently finds all matching lines. Examples: Searches for the word “security” in ‘messages.log’. Ignores case, finding both “Security” and “security”. Outputs matches preceded by the line […]
head
The head command in Linux is a versatile tool used to display the beginning of a file. By default, it shows the first six lines, making it ideal for quickly previewing large files without reading through their entirety. Examples: Displays the first ten lines of filename. Displays the first 16 lines of file.txt. Redirect a […]
ssh
The `ssh` command in Linux stands for Secure Shell and is used for establishing a secure remote connection between two computers. It encrypts data during transmission, making it ideal for tasks like remote login, file transfers, and executing commands on distant servers. Examples of SSH Commands: Connects to a remote server using the specified username […]