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External Interfaces [ HP Pascal/iX Programmer's Guide ] MPE/iX 5.0 Documentation


HP Pascal/iX Programmer's Guide

External Interfaces 

Your program can interface with its external environment (other routines
and files supported by the operating system) by using physical files,
external routines, and intrinsics.

A physical file is a program-independent entity that the operating system
maintains.  It can be a permanent file on a disk or other medium, or it
can be an interactive file created at a terminal.  Your program can
manipulate a physical file by associating it with a logical file (a file
that the program declares).  Chapter 3, "Input/Output," explains physical
and logical files, which HP Pascal programs use for input/output.

An external routine is a routine that is not in the compilation unit that
calls it.  Its source language can be HP Pascal, HP C, HP COBOL II/XL, HP
FORTRAN 66/V, HP FORTRAN 77, or SPL. Your program can access an external
routine by declaring it with the EXTERNAL directive.  Chapter 9 explains
external routines.

An intrinsic is an external routine that can be called by a program
written in any language that the operating system supports.  An intrinsic
can be written in any supported language, but its formal parameters must
be of types that have counterparts in all the other supported languages.
Your program can access an intrinsic by declaring it with the INTRINSIC
directive.  You need not declare the intrinsic's entire parameter list,
and your program can use an intrinsic function as either a function or a
procedure.  Refer to Chapter 10  for more information on intrinsics.



MPE/iX 5.0 Documentation