Fixed-Width Format
In the fixed-width format each field occupies a fixed column range, with no delimiter; fields are located by position, common in mainframe and banking data.
Purpose
To provide a compact delimiter-free and quote-free format for legacy systems and high-throughput batch processing, parsed by column offset.
Mechanism
Each field defines a start column and a width; parsing cuts the substring [start, start+width) and trims it. Numbers are right-aligned, text left-aligned, padded with spaces. A COBOL copybook describes the layout.
Use cases
- Mainframe data exchange
- Bank reconciliation files
- COBOL batch processing