The C language is a general-purpose, function-oriented programming language that you can use to create applications quickly and easily. C provides high-level control statements and data types similar to other structured programming languages as well as many of the benefits of a low-level language. Portable code is easily written in the C language.

This book describes the library functions provided by The IBM Developer's Toolkit for OS/2 Warp Version 4 (referred to in this book as The Developer's Toolkit) product. Many of the functions are defined by the following language standards:

• The American National Standards Institute C Standard and International Standards Organization, ANSI/ISO 9899-1990[1992], and the amendment ISO/IEC 9899:1990/Amendment 1:1993(E)
  
• The ISO/IEC 9945-1:1990/IEEE POSIX 1003.1-1990 standard
  
• The X/Open Common Applications Environment Specification, System Interfaces and Headers, Issue 4
  
• The IBM Systems Application Architecture (SAA) C Level 2 language definition.

Unless explicitly indicated otherwise, all of the library functions described in this book are also available to C++ programs.