Microsoft KB Archive/32423

Sequential and Relative File Formats

PSS ID Number: Q32423 Article last modified on 04-21-1993

3.00 MS-DOS

Summary: For Sequential and Relative files in Microsoft COBOL Version 3.0, the fixed- and variable-mode formats differ considerably in structure. Fixed-mode files have no file or record headers, and all records are assumed to be the same length (equal to the length of the longest record defined) with short records padded with ASCII spaces. Relative file records are followed by a 2-byte delimiter indicating the presence or otherwise of a record in a slot. Variable-format files have a 128-byte file header containing information on the organization, record lengths, recording mode, and date/time of creation or update. Each record is preceded by a record header containing the length of the record and some other flags. The record itself is only the length given, with no padding. Relative file records are also terminated by the same 2-byte delimiter as fixed-format Relative files.

Additional reference words: 3.00 Copyright Microsoft Corporation 1993.