This book is a complete reference to the C programming language and the C runtimelibrary. As an “In a Nutshell” book， its purpose is to serve as a convenient， reliablecompanion for C programmers in their day-to-day work. It describes all the elements ofthe language and illustrates their use with numerous examples.The present description of the C language is based on the 2011 international C standard，ISO/IEC 9899:2011， widely known as C11. This standard supersedes the C99 standard，ISO/IEC 9899:1999， and its Technical Corrigenda， TC1 of 2001， TC2 of 2004， and TC3 of2007. The first international C standard， ISO/IEC 9899:1990， was published in 1990 andsupplemented in 1995 by Normative Addendum 1 （ISO/IEC 9899/AMD1:1995）。 The1990 ISO/IEC standard corresponds to the ANSI standard X3.159， which was ratified inlate 1989 and is commonly called ANSI C or C89.The new features of the 2011 C standard are not yet fully supported by all compilers andstandard library implementations. In this book， we have therefore labeled 2011 features —such as multithreading， type-generic macros， and new standard library functions — withthe abbreviation C11. Extensions that were introduced by the C99 standard are labeledwith the abbreviation C99.This book is not an introduction to programming in C. Although it covers thefundamentals of the language， it is not organized or written as a tutorial. If you are new toC， we assume that you have read at least one of the many introductory books， or that youare familiar with a related language， such as Java or C+