Book Image

Learn C Programming

By : Jeff Szuhay
Book Image

Learn C Programming

By: Jeff Szuhay

Overview of this book

C is a powerful general-purpose programming language that is excellent for beginners to learn. This book will introduce you to computer programming and software development using C. If you're an experienced developer, this book will help you to become familiar with the C programming language. This C programming book takes you through basic programming concepts and shows you how to implement them in C. Throughout the book, you'll create and run programs that make use of one or more C concepts, such as program structure with functions, data types, and conditional statements. You'll also see how to use looping and iteration, arrays, pointers, and strings. As you make progress, you'll cover code documentation, testing and validation methods, basic input/output, and how to write complete programs in C. By the end of the book, you'll have developed basic programming skills in C, that you can apply to other programming languages and will develop a solid foundation for you to advance as a programmer.
Table of Contents (33 chapters)
Section 1: C Fundamentals
Section 2: Complex Data Types
Section 3: Memory Manipulation
Section 4: Input and Output
Section 5: Building Blocks for Larger Programs

Trimming the input string from fgets()

It would be extremely handy if the C Standard Library provided routines to trim whitespace both before and after a string. As we have seen, some of the input routines preserve whitespace, including <newline>, and some of the routines do not. Other languages provide functions such as trimLeft(), trimRight(), and trim(), that trim both the left and right sides of a string.

Thankfully, writing such a function is not too cumbersome in C. Consider the following function:

int trimStr( char* pStr ) {
size_t first , last , lenIn , lenOut ;
first = last = lenIn = lenOut = 0;

lenIn = strlen( pString ); //
char tmpString[ lenIn+1 ]; // Create working copy.
strcpy( tmpStr , pString );//
char* pTmp = tmpStr; // pTmp may change in Left Trim segment

// Left Trim
// Find 1st non-whitespace char; pStr will point to that.
while( isspace( pTmp[ first ] ) )
pTmp += first;
lenOut = strlen( pTmp ); // Get new length after Left Trim.
if( lenOut...