XPORT Programmers Guide Apr81

This document is the XPORT Programmer's Guide, published by Digital Equipment Corporation in April 1981. It serves as a tutorial and reference manual for XPORT Version 1.0, a suite of transportable programming tools designed for the BLISS language across various DEC operating systems (VAX/VMS, TOPS-10, TOPS-20).

The guide focuses on enabling source-level transportability by providing facilities for:

• Transportable Data Structures: Using macros like $FIELD to define data structures that adapt to architectural differences across systems, with features for field positioning, literal definitions, and display.
• System-Independent Input/Output (I/O): A uniform interface for file-level operations (e.g., open, close, delete, rename, backup) and sequential I/O in record, character-stream, and binary modes, managed through Input/Output Blocks (IOBs) and supporting file specification resolution and parsing.
• Dynamic Memory Management: Macros for allocating and releasing memory elements.
• Comprehensive String and Binary Data Handling: Features for creating, initializing, modifying, comparing, scanning, and converting data using specialized descriptors.
• Other System Services: Including message generation and orderly program termination, with built-in error handling through completion codes and action routines.

The manual also includes detailed descriptions of all XPORT macros, control block structures, completion codes, sample programs, and a debugging utility (XDUMP), along with guidance on compiling and linking XPORT programs.