The Geek Diary

At one point or another, you have used a joystick or a gamepad of a video console. A joystick is nothing more than a series of buttons and potentiometers. With this device, you can perform or control a wide range of actions. When you connect your joystick to your computer, you are going to check […]

jq is a lightweight and flexible command-line JSON processor much like sed in that it enables you to slice, filter, map, and transform data from one format to another. For instance, it can be used to convert JSON data into CSV (comma-separated values) for loading into a non-JSON–columned MySQL database. You can download it from […]

Debian’s package management system uses the dpkg command to install, remove, and query packages. dpkg-deb is a backend command for building and managing Debian package archives. You’ll often want to use dpkg to pass commands through to dpkg-deb, rather than call dpkg-deb directly. If you encounter below error: dpkg-deb: command not found You may try […]

Quick Emulator (QEMU) is the main component of the QEMU/KVM virtualization technology suit. It provides hardware virtualization and processor emulation. QEMU runs in userspace and, without the need for kernel, drivers can still provide fast system emulation. QEMU supports two operating modes: Full system emulation, where QEMU emulates an entire computer system, including the CPU […]

There are several limitations to consider when preparing for and performing a live migration. One of them is that no operations can be performed on a virtual machine that is being live migrated. Still, you can use virsh on the source compute node to interact with the virtual machine. Specifically: 1. View the current state […]

The traditional Linux and Unix way for finding code coverage is to use gcov to generate the coverage map and lcov to make the output pretty. Code coverage measures if, and if so, how many times, a line of code is executed. This is useful for measuring the efficacy of your test code. In theory, […]

Installed with PulseAudio are the PulseAudio utilities (pulseaudio-utils package). These are command-line utilities for managing PulseAudio and playing sound files. The paplay and pacat will play sound files; pactl will let you control the sound server; and pacmd lets you reconfigure it. Check the man pages for each for more details. Sound Tool Description pabrowse […]

exFAT is the newest Microsoft 64-bit filesystem, a nice upgrade from FAT32. exFAT is a fast, lightweight filesystem for USB sticks and SD media, and supports much larger file and volume sizes than FAT32. Wikipedia cites a 16 EiB maximum file size and 128 PiB maximum volume size. It does not have a journal or […]

arch-chroot command is used to create chroot jail which changes the root directory from the current one (in the virtual system booted from the ISO image) to the real one that is on your disk. Thus, the rest of the commands will consider your disk as the currently booted system and apply the changes. Note […]

vdir command verbosely lists directory contents. Equivalent to ls -lb. By default, list the current directory. Directory entries are sorted alphabetically unless overridden by an option. vdir takes the same options as ls. Syntax Syntax of the vdir command is: $ vdir [options] [files] If you encounter below error: vdir: command not found you may […]