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Version: 3.1.X

isofile_match_with_fdt

Overview​

isofile_match_with_fdt is a CISIS utility designed to validate and match ISO-2709 records against a Field Definition Table (FDT).

Its primary goal is to ensure that the fields present in an ISO file are compatible with the field structure defined in a given FDT, identifying inconsistencies, undefined fields, and structural mismatches before database loading or migration.

This tool is particularly useful in ABCD workflows, where FDT consistency is critical for correct indexing, data entry forms, and record validation.

Purpose​

The utility performs the following tasks:

  • Reads an ISO-2709 input file record by record

  • Loads and parses an FDT file

  • Extracts field tags from each ISO record

  • Compares record fields against:

    • Defined FDT field tags
    • Field properties and constraints

  • Reports mismatches and inconsistencies

  • Optionally filters or flags problematic records

Supported Standards​

  • Input format: ISO 2709
  • FDT format: CDS/ISIS Field Definition Table
  • Output: Validation messages (stdout / log-style output)

Command-Line Usage​

isofile_match_with_fdt -i <input.iso> -f <database.fdt> [options]

Command-Line Options​

OptionDescription
-iPath to the ISO input file
-fPath to the FDT file
-rReports records with undefined or invalid fields
-sSilent mode (only critical errors reported)
-vDisplays version information
-hDisplays help and usage instructions

Processing Logic​

1. FDT Loading​

  • Opens the specified FDT file

  • Parses:

    • Field tags
    • Field attributes

  • Stores FDT entries internally for fast lookup

2. ISO Record Processing​

For each ISO-2709 record:

  1. Read record leader
  2. Parse directory entries
  3. Extract field tags
  4. Compare each field tag with the loaded FDT definitions

Matching Rules​

A field is considered valid if:

  • The field tag exists in the FDT
  • The tag follows expected numeric formatting
  • The entry does not violate internal FDT constraints

A field is considered invalid if:

  • The tag does not exist in the FDT
  • The directory entry is malformed
  • The field structure exceeds predefined limits

Output Behavior​

The utility reports:

  • Record number
  • Field tag involved
  • Description of the inconsistency

Example output:

Record 124:
  Undefined field: 950
Record 130:
  Field not declared in FDT: 990

This output is intended for diagnostic and corrective workflows, not for direct machine consumption.

Error Handling​

The utility includes protections against:

  • Invalid directory entry counts
  • Malformed ISO records
  • Missing or unreadable FDT files

When a fatal error is detected, processing stops to avoid misleading results.

Limitations​

  • The utility performs structural matching only

  • It does not validate:

    • Subfield content
    • Repeatability rules
    • Input masks or value ranges

  • Assumes the ISO file is structurally correct (ISO-2709 compliant)

Typical Use Cases in ABCD​

  • Pre-validation of ISO files before database import
  • Ensuring legacy records match current database structures
  • Debugging indexing or search issues caused by undefined fields
  • Auditing ISO exchanges between different ABCD installations

Compilation​

Typically compiled as part of the CISIS toolchain:

gcc -o isofile_match_with_fdt isofile_match_with_fdt.c [cisis libraries]

Compilation flags depend on the CISIS version and local build configuration.

  • mx
  • isofile_iso_to_utf
  • i2id
  • isisvalidate