Ubuntu Unleashed, Second Edition

more than 50 different software packages and 110MB of hard drive space. If you plan to

build programs for the Linux kernel, you need the Kernel development packages and an

additional 180MB of storage space (not counting temporary disk space required when

building a new kernel).

You should also become familiar with a good text editor. Although GNU purists use the

emacs editing environment to write, edit, and compile programs, many other developers

do just fine with an editor such as

vi or nano for editing source and then use the

command line to run development tools.

When programming for GNOME or KDE, you might find it most convenient to use a

graphical development project manager, such as GNOME’s Glade (the GTK+ User

Interface Builder,

glade-2), Trolltech’s Qt Designer (designer), or KDE’s KDevelop (the

KDE development environment,

kdevelop). These clients enable you to prototype an applica-

tion with graphical drawing tools, which frees you to concentrate on your client’s inter-

face. You can use either to automatically generate all necessary project and source code

files for skeletal applications. See the section “Graphical Development Tools,” later in this

chapter, for more information.

The Process of Programming

Many Linux C programmers start by writing a program that solves an immediate need,

such as a simple command-line program to download or upload phone numbers or other

data to a cellular phone or handheld computer. Many beginners get started by becoming

proficient in using a Linux text editor, researching any required software routines and

reading documentation, browsing available Linux source code, learning how to run a

compiler (such as

gcc, discussed later in this chapter), and then launching into the itera-

tive process of editing, compiling, executing, and testing.

The following sections in this chapter discuss some of the required or helpful software

tools included with Ubuntu. You also see how to create, compile, and run a simple C

program. You’ll also see how to use several graphical prototyping tools (such as Glade,

Designer, or KDevelop) to shorten the process of developing a user interface for graphical

programs; these tools can free up time and effort on those tasks, allowing you to concen-

trate on the core functions of your new program.

Elements of the C/C++ Language

The C programming language has its own syntax—a specific form in which all commands

and code must be written in order to be understood and processed by the computer

system. The syntax you should understand when beginning to program in C includes the

following:

. Comments—Comments are statements that document code and describe the

program. A comment begins and ends with special characters, such as

/* and */,

that tell the compiler to ignore all content between those characters.

Elements of the C/C++ Language

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