When you define a variable in Java, you must tell the compiler what kind of a variable it is. That is, whether it will be expected to store an integer, a character, or some other kind of data. This information tells the compiler how much space to allocate in the memory depending on the data […]
Archives for September 2021
Basics of Java Variables
A variable is a location in the computer’s memory where a value is stored and from which the value can be retrieved later. Variables are used in a Java program to store data that changes during the execution of the program. They are the basic units of storage in a Java program. Variables can be […]
env Command Examples in Linux
The env command is used to run a command with modified environment variables. By supplying the name of a variable and a value in the key-value pair format, as well as supplying a command to run, you can change the value of the specified variable for that particular command session. If the variable does not […]
gzip Command Examples in Linux
GNU zip (gzip) is a compression utility that reduces the size of selected files. Files compressed with gzip frequently have the .gz file extension. The gzip command has several options. These command options are described in the following table. Option Used To -d Reverse file compression (decompression). -f Force compression or decompression of a file […]
dd Command Examples in Linux
The dd command copies and converts files to enable them to be transferred from one type of media to another. The dd command has various operands, or actions, to perform. Operand Used To if={file name} Specify the file from which data will be read. of={file name} Specify the file to which data will be written. […]
rsyslogd Command Examples in Linux
The syslogd service is the original syslog service on Linux. The rsyslogd service makes several improvements, including support for: TCP instead of UDP as the transport protocol, increasing the reliability of transmitted data. Data encryption using SSL/TLS. Outputting data to various database technologies like MySQL. Buffering data on local systems when the remote receiver is […]
tar Command Examples in Linux
Linux often uses two particular utilities to help manage files. The first utility is tape archiver or tar. The second is a compression utility such as gzip. The purpose of tar is to bundle together multiple files into a single tarball with a .tar extension. This makes functions like downloads much easier since there is […]
yum Command Examples in Linux
The yum command improves the functionality of rpm while still using .rpm packages and maintaining an RPM database. It provides a more straightforward method for managing packages. One of the biggest benefits of YUM is the ability to automatically handle software dependencies. This means that administrators can tell YUM to install a particular package, along […]
route Command Examples in Linux
It is possible to configure a Linux system to act as a router. The role of a router is to pass traffic from one network segment to another, based on the network ID of packets. In order to properly direct traffic to the appropriate subnet (and prevent traffic from getting to certain subnets, too), routing […]
netstat Command Examples in Linux
The netstat (network statistics) command is used to gather information about TCP connections to the system. Depending on the options used, netstat informs the user of existing connections, listening ports on the server, NIC information, etc. Common options for the netstat command include: Option Used To -v Activate verbose mode. -i [interface] Display info about […]