Book Image

Practical C Programming

By : B. M. Harwani
Book Image

Practical C Programming

By: B. M. Harwani

Overview of this book

Used in everything from microcontrollers to operating systems, C is a popular programming language among developers because of its flexibility and versatility. This book helps you get hands-on with various tasks, covering the fundamental as well as complex C programming concepts that are essential for making real-life applications. You’ll start with recipes for arrays, strings, user-defined functions, and pre-processing directives. Once you’re familiar with the basic features, you’ll gradually move on to learning pointers, file handling, concurrency, networking, and inter-process communication (IPC). The book then illustrates how to carry out searching and arrange data using different sorting techniques, before demonstrating the implementation of data structures such as stacks and queues. Later, you’ll learn interesting programming features such as using graphics for drawing and animation, and the application of general-purpose utilities. Finally, the book will take you through advanced concepts such as low-level programming, embedded software, IoT, and security in coding, as well as techniques for improving code performance. By the end of this book, you'll have a clear understanding of C programming, and have the skills you need to develop robust apps.
Table of Contents (20 chapters)

Counting the number of vowels in a file

In this recipe, we will open a sequential text file and count the number of vowels (both uppercase and lowercase) that it contains.

In this recipe, I will assume that a sequential file already exists. Please read Appendix A to learn how to create a sequential file.

How to do it…

  1. Open the sequential file in read-only mode using the following code:
fp = fopen (argv [1],"r");
  1. If the file does not exist or does not have enough permissions, an error message will be displayed and the program will terminate, as shown in the following code:
if (fp == NULL) {
printf("%s file does not exist\n", argv[1]);
exit(1);
}
  1. Initialize the counter that will count the...