Book Image

Extreme C

By : Kamran Amini
5 (1)
Book Image

Extreme C

5 (1)
By: Kamran Amini

Overview of this book

There’s a lot more to C than knowing the language syntax. The industry looks for developers with a rigorous, scientific understanding of the principles and practices. Extreme C will teach you to use C’s advanced low-level power to write effective, efficient systems. This intensive, practical guide will help you become an expert C programmer. Building on your existing C knowledge, you will master preprocessor directives, macros, conditional compilation, pointers, and much more. You will gain new insight into algorithm design, functions, and structures. You will discover how C helps you squeeze maximum performance out of critical, resource-constrained applications. C still plays a critical role in 21st-century programming, remaining the core language for precision engineering, aviations, space research, and more. This book shows how C works with Unix, how to implement OO principles in C, and fully covers multi-processing. In Extreme C, Amini encourages you to think, question, apply, and experiment for yourself. The book is essential for anybody who wants to take their C to the next level.
Table of Contents (23 chapters)

Removal of the gets function

In C11, the famous gets function is removed. The gets function was subject to buffer overflow attacks, and in older versions it was decided to make the function deprecated. Later, as part of the C11 standard, it was removed. Therefore, older source code that uses the gets function won't be compiled using a C11 compiler.

The fgets function can be used instead of gets. The following is an excerpt from the gets manual page (man page) in macOS:

SECURITY CONSIDERATIONS
The gets() function cannot be used securely. Because of its lack of bounds checking, and the inability for the calling program to reliably determine the length of the next incoming line, the use of this function enables malicious users to arbitrarily change a running program's functionality through a buffer overflow attack. It is strongly suggested that the fgets() function be used in all cases. (See the FSA.)