How to Linux Blog

Using an Arduino board and optiLoader

if Arduino ISP hacks are not working, there is still hope ! And it is called optiLoader. This project, initiated by Bill Westfield is ‘based’ on the ArduinoISP sketch. Optiloader is a sketch designed for...

Reset  User Password in Ubuntu 12.04 using Recovery Mode

Reset User Password in Ubuntu 12.04 using Recovery Mode

This brief tutorial is going to show you how to easily reset your forgotten password in Ubuntu 12.04 Precise. This short tutorial is going to show you . To get started, power on your...

Hide database from user

Hide database from user

These two queries will restrict a user to a single database, so that the user can only see, update, and delete tables from that single database: Replace USER with the MySQL username Replace USERDATABASE...

Restoring a MySQL table back to the database

Restoring a MySQL table back to the database

When we need to restore a single MySQL table from big data MySQL backup.  Most modern text editors should be able to handle a text file that size, if your system is up to it....

PHP Client IP address

PHP Client IP address

Many times we need the visitor’s ipaddress for validation, security, spam prevention, etc. Getting the Visitor’s ipaddress is very easy in PHP. The simplest way to get the visitor’s/client’s ipaddress is using the$_SERVER[‘REMOTE_ADDR’] or $_SERVER[‘REMOTE_HOST’] variables. 1...

DIY SMD metal stencils – the definitive tutorial

DIY SMD metal stencils – the definitive tutorial

In previous posts (here and here) I described my efforts and research to develop a DIY method to make good quality SMD metal stencils at home. I have since experimented some more and I believe I...

Rescue guide for your Adafruit ATmega32u4 breakout board

Rescue guide for your Adafruit ATmega32u4 breakout board

The ATmega32u4 breakout board is a beta product. The hardware is essentially perfect, but the firmware is wonky. At least once, I’ve convinced myself that mine was broken, but I eventually figured it out. Here’s how...

Bootloading an ATmega32u4 with Arduino

Bootloading an ATmega32u4 with Arduino

A month or two ago I ordered some of Atmel’s ATmega32u4 microcontrollers to play around with. I was excited to get them, but at the time I was really busy at work, so I...

Adafruit ATMega32u4 as Arduino

Adafruit ATMega32u4 as Arduino

You can use the Adafruit ATMega32u4 breakout board  as an Arduino Leonardo by flashing the bootloader in Arduino 1.0.1 to the board. To follow this process, you use another Arduino, like the Arduino Duemilanove, as a...

Simple shell script to backup MySQL databases

Simple shell script to backup MySQL databases

Simple shell script to backup MySQL databases.

Example output (with mysql password stored inside script):