model(4)						     Kernel Interfaces Manual							  model(4)

NAME

       model - HP-UX machine identification

SYNOPSIS

DESCRIPTION

       There are certain inevitable distinctions between HP-UX implementations due to hardware differences.  Where such distinctions exist, condi-
       tional compilation or other definitions can be used to isolate the differences.	Flags and typedefs to resolve these distinctions are  col-
       lected in the header file which contains constants identifying various HP-UX implementations.

       For example, header file contains the following constants whose values are defined in

       Other such constants are added as appropriate when HP-UX extends to other machines in subsequent releases.

       In  addition, has a statement defining the preprocessor constant to represent the specific implementation for which compilation is desired.
       is always equal to one of the constants above.

       Conditional compilation can be used to adapt a single file for execution on more than one HP-UX implementation if the file contains  imple-
       mentation- or architecture-dependent features.  For example, the code segment:

		   <statements>

       causes statements following the if statement to be compiled if the system processor is an HP 9000 Series 400 machine.

       also contains typedefs for several predefined types to enhance portability of certain types of code and files.

       These typedef declarations have been replaced by the header file

	      Signed and unsigned 8-bit integral type.
	      Signed and unsigned 16-bit integral type.
	      Signed and unsigned 32-bit integral type.
	      Signed and unsigned integral type large enough to hold a pointer.

       To port code to use instead of these are the corresponding definitions contained in

	      Signed and unsigned 8-bit integral types.
	      Signed and unsigned 16-bit integral types.
	      Signed and unsigned 32-bit integral types.
	      Signed and unsigned integral large enough to hold a pointer.

       Certain C preprocessor conditional compilation variables are defined to aid in implementation-dependent code.  See cpp(1).

SEE ALSO

       cc(1), cpp(1), inttypes(5), magic(4).

								  TO BE OBSOLETED							  model(4)