Extracting a bootable disk image from an ISO image (El Torito)

The El Torito Bootable CD Specification was introduced in the 90's to make it possible to boot a system from a CD. This specification is used till today for bootable ISO images. There are different ways to embed disk images into El Torito ISO images. One way is called hard disk emulation. With this the bootable disk image comes with a DOS/MBR boot record and can be booted by the BIOS/UEFI directly. Unfortunately if you want to boot such an ISO from an USB stick, that won't work out of the box, you need to extract the disk image from the ISO first. This article is about how you can do that easily under Linux.

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How to change the bluetooth device address (BD_ADDR)

Cheap bluetooth adapters often share the same bluetooth address (BD_ADDR). That is especially a problem if you want to use both at the same time with the same device. Fortunately one can change the address of a bluetooth adapter with the bdaddr command (delivered with recent versions of bluez-utils). This is a quick howto for recent versions of bluez.

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Python 2 vs Python 3: Bytes and Strings

Many Linux distributions will or have already switched over to Python 3 as default interpreter when running the python command. At the same time many people are still used to Python 2 and might not be aware of the changes that come with that switch. Especially string and byte handling is different from Python 2. This article is about some common pitfalls and how to prevent them with Python 3.

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One-liner #2: Enabling and Disabling Synaptic Touchpads

If you have a notebook with one of these large touchpads you might have come across this problem: You type something on the keyboard and suddenly the cursor jumps to a different location messing up your text (because you accidently touched the touchpad with your palm). To avoid this syndaemon allows you to automatically lock the touchpad when you type something on the keyboard. Desktop environments like XFCE make use of it. The downside of that is, that it can result in a frozen mouse pointer (for some milliseconds or seconds). Therefore I prefer to disable the touchpad manually by using a shortcut whenever I need that feature.

This post shows a one liner which allows you to disable your Synaptics touchpad temporarily. The same command allows you to enable it later again. By binding the command to a shortcut, you can easily toggle between an enabled or disabled touchpad.

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