Book Image

Learn C Programming. - Second Edition

By : Jeff Szuhay
Book Image

Learn C Programming. - Second Edition

By: Jeff Szuhay

Overview of this book

The foundation for many modern programming languages such as C++, C#, JavaScript, and Go, C is widely used as a system programming language as well as for embedded systems and high-performance computing. With this book, you'll be able to get up to speed with C in no time. The book takes you through basic programming concepts and shows you how to implement them in the C programming language. Throughout the book, you’ll create and run programs that demonstrate essential C concepts, such as program structure with functions, control structures such as loops and conditional statements, and complex data structures. As you make progress, you’ll get to grips with in-code documentation, testing, and validation methods. This new edition expands upon the use of enumerations, arrays, and additional C features, and provides two working programs based on the code used in the book. What's more, this book uses the method of intentional failure, where you'll develop a working program and then purposely break it to see what happens, thereby learning how to recognize possible mistakes when they happen. By the end of this C programming book, you’ll have developed basic programming skills in C that can be easily applied to other programming languages and have gained a solid foundation for you to build on as a programmer.
Table of Contents (37 chapters)
1
Part 1: C Fundamentals
10
Part 2: Complex Data Types
19
Part 3: Memory Manipulation
22
Part 4: Input and Output
28
Part 5: Building Blocks for Larger Programs

Chapter 20: Getting Input from the Command Line

Up until this point, we have not read any input for any of our programs from any source. All program data has been hardcoded in the program itself. In this chapter, we will begin exploring programming input with one of the simplest available methods—inputting from the console's command line.

We will revisit the main() function with our added knowledge of function parameters and arrays of strings. We will then explore how to retrieve strings via an argument to the main() function.

The following topics will be covered in this chapter:

  • Understanding the two forms of main()
  • Understanding how argc and argv are related
  • Writing a program to retrieve values from argv and printing them
  • Understanding how to use getopt() for simple command-line processing

So, let's dive right in!