In this book, you will find a number of text styles 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: "The rosdep command-line tool must be installed and initialized before you can use ROS."

A block of code is set as follows:

#include <ros/ros.h>
#include <dynamic_reconfigure/server.h>
#include <chapter2_tutorials/chapter2Config.h>

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

dynamic_reconfigure::Server<chapter2_tutorials::chapter2Config>::CallbackType f;

  f = boost::bind(&callback, _1, _2);

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

$ sudo apt-get install python-rosdep
$ sudo rosdep init
$ rosdep update

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "When it finishes, you can start your virtual machine by clicking on the Start button."