C language Pocket reference (1. Introduction)

(Original book: C pocket reference)

CLanguage pocket reference

C language Pocket Reference Manual is a very good book: it can be used as a beginner's entry book, but also as an advanced quick reference manual. This book consists of two parts: Introduction to the C language syntax and introduction to the standard library. The C language syntax in this book is based on the ANSI standard published in 1999 and includes some extensions. In order to allow readers to quickly find the desired content, this book provides an index.

 

1.Introduction

In 1970s, Dennis Ritchie worked in Bell Labs when he developed Unix OS for Dec PDP-11 computers, during which he developed C language. C language originated from the weak programming language BCPL (Basic combined programming language) and B. In 1978, Brian kernighan and Dennis Ritchie released the C language standard for the first time, which is a well-known K & R Standard.

C language is a lightweight programming language for modern computer technology. The language itself is small and almost independent of any hardware. For example, it neither includes the input/output status nor the memory management technology. All functions that complete these functions are included in the extended C standard library.

Significant advantages of C language:

• Simple and compact code

• High machine code execution efficiency

• Almost every system can find the C compiler that can run on it

The first part of this pocket Reference Guide describes the C language and the second part describes the C standard library. The C language is based on the ANSI x3.159 standard, which corresponds to the international standard ISO/IEC 9899. This international standard was published by the International Organization for Standardization in 1990 and was revised in 1995 and 1999, respectively. To obtain the ISO/IEC 9899 standard, log on to the ANSI website. For more information, see http://ansi.org/public/std_info.html.

Currently, almost all common C compilers support the 1995 standard. The extended definition (simplified as ANSI c99) released in 1999 may not be implemented in many compilers, so it will be labeled in this book. The newly added types, functions, and macro definitions in ANSI c99 are marked.

1.1Font conventions

The font printing in this book follows the following conventions:

Italics

Used to introduce new terms or file names.

Same Width font

It is used to represent the C language code and also includes the operator functions and commands.

Equal-width italics

It indicates that the syntax is replaceable.

Same-width simhei

Highlight part of the Code to make it more eye-catching.

(Not yet to be continued. Update again after May 1 :))