Overview
ISO/IEC 7942-3:1999 - Information technology: Graphical Kernel System (GKS) - Part 3: Audit trail specifies a file format for recording the sequence of GKS (GKS-94) function calls and their parameters so that a recorded session can be replayed later. The standard defines the structure and grammar of an audit trail file, conventions for element naming, and representations for complex parameter types used by GKS. It is part of the ISO/IEC 7942 family (see Parts 1 and 2).
Keywords: ISO/IEC 7942-3:1999, Graphical Kernel System, GKS audit trail, audit trail file format, GKS-94, computer graphics, playback.
Key topics
- Audit-trail structure
- An audit trail is a sequence of elements bounded by
BEGIN-AUDIT-TRAIL and END-AUDIT-TRAIL.
- Each element corresponds to a GKS function (element names derived from function names).
- Keywords in the audit trail are case-sensitive.
- Grammar and syntax
- The standard provides a formal grammar describing which audit elements must or may appear.
- Suggested concrete syntax uses element names followed by parameter lists in parentheses; implementations may adopt compact representations.
- Data representation rules
- Defines how to represent GKS abstract data types in the file: constants, set types, tuples, functions, discriminated unions and sequences.
- Examples from the standard: sets as
PSET(...), sequences as SEQ(...), tuples as Type(x), function mappings as PSET(Type(-+), ...).
- Implementation considerations
- The representation of basic types (e.g., how names or numbers appear) is left implementation-dependent.
- The standard focuses on recording and playback by the same GKS implementation; portability across different implementations is not covered.
Applications
- Replay and debugging: Capture exact sequences of graphical API calls for regression testing, debugging and diagnostics of GKS-based applications.
- Archiving and provenance: Store reproducible records of generated graphics for long-term archives or audit trails in regulated environments.
- Interoperability testing: Validate consistent behavior of a single GKS implementation across sessions (note: cross-implementation portability is outside this part).
- Tooling and automation: Basis for building playback tools, simulators or visualization repeaters that reproduce previously recorded GKS activity.
Who uses it: graphics software developers, GKS implementers, QA/test engineers, digital archivists, and standards professionals working with computer graphics and image processing.
Related standards
This concise specification is valuable when you need a formal, grammar-based file format to capture and replay GKS function sequences for testing, archival, or diagnostic playback of computer-graphics applications.
Open preview (PDF)Information technology — Computer graphics and image processing — Graphical Kernel System (GKS) — Part 3: Audit trail
