In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Now we need to start the imagewriter.py script and tell it where to find the Raspbian IMG file."

A block of code is set as follows:

prepare_tv() {
  tv_off # We switch the TV off and on again to force the active channel to the Pi
  sleep 10 # Give it a few seconds to shut down
  echo "on 0" | cec-client -d 1 -s # Now send the on command
  sleep 10 # And give the TV another few seconds to wake up
  echo "as" | cec-client -d 1 -s # Now set the Pi to be the active source
}

Any command-line input or output is written as follows:

pi@raspberrypi ~ $ sudo wget http://goo.gl/1BOfJ -O /usr/bin/rpi-update && sudo chmod +x /usr/bin/rpi-update

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "When your image has finished downloading, you'll need to unzip it, usually by right-clicking on the ZIP file and selecting Extract all or by using an application such as WinZip."