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 (38 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

Opening files for reading and writing

We can now create a program to open a file for reading and another file for writing. This is where our file I/O exploration will begin and continue through the remaining chapters of this book. The following program is our starting point:

#include <stdio.h>
#include <stdlib.h>     // for exit()
#include <string.h>     // for strerror()
#include <sys/errno.h>  // for errno
int main( void ) {
  FILE* inputFile;
  FILE* outputFile;
  
  char inputFilename[] = "./input.data";
  char outputFilename[] = "./output.data";
  
  inputFile = fopen( inputFilename , "r" );
  if( NULL == inputFile )  {
    fprintf( stderr, "input file: %s: %s\n", 
     ...