Handle Multi-Record-Type Fixed-Width Files

Multi-Record-Type Files

Many fixed-width files contain different types of records in a single file, each with a different layout. A common pattern is Header / Detail / Trailer (HDT):

Example File

H20240115BATCH001Company Inc
D001ALICE SMITH        000012345620240110
D002BOB JONES          000098765620240112
D003CHARLIE BROWN      000000150020240114
T003000111261220240115

Record Structures

Header (H):

Field	Pos	Width
RecType	0	1
BatchDate	1	8
BatchID	9	8
CompanyName	17	24

Detail (D):

Field	Pos	Width
RecType	0	1
SeqNo	1	3
Name	4	20
Amount	24	10
Date	34	8

Trailer (T):

Field	Pos	Width
RecType	0	1
RecCount	1	3
TotalAmount	4	10
Date	14	8

Processing Strategy

Since this tool uses a single column definition at a time, process multi-record files in stages:

1. Identify the record type field (usually the first 1-2 characters)
2. Filter lines by type — manually or with a text editor
3. Convert each type separately with its own column definition
4. Combine the results if needed

Tips

• The record type indicator is almost always at the very beginning of each line
• Use presets to quickly switch between different column layouts
• Save your column definitions for each record type for reuse