Guardian C Library Calls Reference Manual

Guardian TNS C Library Calls Reference Manual—128833 2-1

Summary of Library Header Files

The macros and functions in the Guardian TNS C run-time library are declared in 20

header files. Each header contains declarations for a related set of library functions and

macros, as well as variables and types that complete that set. If you use a function in the

library, you should include the header file in which it is declared. Do not declare the

routine yourself because the declarations in the header files have provisions for several

situations that can affect the form of a given declaration, including:

•

Whether the routine is implemented internally as a function or a macro

•

Whether the function is written in a language other than C

•

Whether you are compiling for the small or large memory model

•

Whether you are compiling for the 16-bit or 32-bit (wide) data model

In addition, the header files use function prototypes to declare functions. These

prototype declarations enable the C compiler to check parameters and arguments for

compatibility, ensuring that calls to the library functions provide the correct number and

type of arguments.

A single set of C library header files support both the Guardian and Open System

Services (OSS) environments.

This section summarizes the contents of the 20 header files that declare the functions,

macros, types, and variables in the C run-time library. These header files are:

asserth ctypeh errnoh fcntlh floath limitsh

localeh mathh memoryh nonstoph setjmph signalh

sqlh stdargh stddefh stdioh stdlibh stringh

talh timeh

The header file cextdecs is described in the C/C++ Programmer’s Guide.

The header asserth defines the assert macro, which enables you to insert run-time

diagnostics in a program. After developing and debugging your program, you can

disable all the diagnostics by defining the identifier NDEBUG as a macro before

including asserth. When you do this, asserth defines assert as:

#define assert(ignore)

This effectively disables all diagnostics.

The header ctypeh declares routines that perform character testing and mapping

operations. These routines are:

isalnum isalpha isascii iscntrl iscsym iscsymf

isdigit isgraph islower isprint ispunct isspace

isupper isxdigit toascii tolower toupper