ICMP requests can be send to another host to test if host is reachable. However, firewalls can block ICMP requests. The arping is a command line tool for sending ARP...

The ioping is a tool that allows to monitor I/O latency via command line. The ioping displays latency of a storage device in the same way as ping command displays...

Linux kernel is the main component of the Linux operating system. To determine which Linux kernel version is running on the system can be useful when troubleshooting issues. This tutorial...

Every Raspberry Pi has a unique serial number. It is assigned during manufacturing. Serial number is a 32-bit number represented by 16 hexadecimal digits (e.g. 100000007184bc7e). This tutorial shows how...

The ps_mem is a command line tool for checking RAM usage for a programs. This tool calculates the amount of RAM (private memory + shared memory) being used by each...

Sysbench is an open-source command line tool that enables to benchmark system by running various tests for CPU, RAM, disk I/O and database (e.g. MySQL). This tutorial demonstrates how to...

The new keyword allows creating an instance of a class. Since PHP 8.1, the new keyword can be used in initializers (e.g. parameter default values, attribute arguments, etc.). In versions...

Since PHP 8.1, we can use enumerations also called enums. Enum defines a custom type that contains a fixed set of related values. Enum is declared using the enum keyword...

Since PHP 8.0, we can use named arguments. These arguments can be passed to a function or class method based on the parameter name. In PHP 8.0, combining named arguments...

Since PHP 8.0, we can use union types which allows providing two or more types for parameters, return values, and properties. The given value should be one of the specified...