The LVM is a powerful storage management module which is included in all the distributions of Linux now. It provides users with a variety of valuable features to fit different requirements. The management tools that come with LVM are based on the command line interface, which is very powerful and suitable for automated/batch operations. But LVM's operations and configuration are quite complex because of its own complexity. So many software companies including Red Hat have launched some GUI-based LVM tools to help users manage LVM more easily. Let’s review them here to see the similarities and differences between individual tools.

It's hard to write a bash script of much import without using a pipe or two. Named pipes, on the other hand, are much rarer.

If you've ever used a spreadsheet, you've probably used or seen functions for doing date math—in other words, taking one date and adding some number of days or months to it to get a new date, or taking two dates and finding the number days between them. The same thing can be done from the command line using the lowly date command, possibly with a little help from Bash's arithmetic.

If you use bash you already know what Parameter Expansion is, although you may have used it without knowing its name. Anytime you use a dollar sign followed by a variable name you're doing what bash calls Parameter expansion, eg echo $a or a=$b. But parameter expansion has numerous other forms which allow you to expand a parameter and modify the value or substitute other values in the expansion process.

I've recently written about using bash arrays and bash regular expressions, so here's a more useful example of using them to test IP addresses for validity.

TACACS+ server implementation for Linux operating system, although neat, lacks a graphical user interface which makes daemon configuration a smooth and intuitive process. In the next few paragraphs, we will discuss how to configure the TACACS+ daemon on Linux operating system and demonstrate how to deploy a simple, yet intuitive, GUI used for the configuration of the TACACS+ instance.

Why does ncurses support only eight colors? If you've looked into the color palette available in curses, you may wonder why curses supports only eight colors. The curses.h include file defines these color macros: COLOR_BLACK COLOR_RED COLOR_GREEN COLOR_YELLOW COLOR_BLUE COLOR_MAGENTA COLOR_CYAN COLOR_WHITE But why only eight colors, and why these particular colors? At least with the Linux console, if you're running on a PC, the color range's origins are with the PC hardware.

At times, we need to write shell scripts that are interactive and user executing them need to monitor the progress. For such requirements, we can implement a simple progress bar that gives an idea about how much task has been completed by the script or how much the script has executed. To implement it, we only need to use the “echo” command with the following options and a backslash-escaped character.

Encryption and secure communications are critical to our life on the Internet. Without the ability to authenticate and preserve secrecy, we cannot engage in commerce, nor can we trust the words of our friends and colleagues.