When working as system administrator in the Linux, might need to change user password. This tutorial demonstrates how to do that in the Linux. To change the password of the...

Nginx web server can fail to start if the configuration file contains errors. If any changes were made in a configuration file, it is recommended to check whether syntax is...

Apache web server can fail to start if the configuration file contains errors. If the configuration file was changed, it is recommended to check for errors before restarting the Apache...

Apache web server has many modules that extend core functionality. This tutorial demonstrates how to check which Apache modules are enabled on Ubuntu. The apache2ctl command can be used to...

When working with files in the Linux systems, there may need to find files or directories by name. This tutorial demonstrates how to do that. Create few directories and files...

A MAC (Media Access Control) address is a unique value assigned to a network interface card (NIC, also called network adapter) by the manufacturer to uniquely identify it. This tutorial...

When working as system administrator in the Linux, may be needed to perform network configurations. Before doing this, it can be useful to determine which network interfaces are available in...

Cryptographic hash functions can be used for verifying file integrity. For example, to check that the file has not been altered during transfer over the network. This tutorial explains how...

Certutil is a command line tool that allows to perform various operations related with digital certificates on Windows. Certutil also allows to generate hash of a file such as MD4...

Nmap is a network scanning tool which has various scripts that provide additional functionality. This tutorial shows how to check SSL certificate on server using Nmap. The ssl-cert script allows...