Microsoft KB Archive/21188

Record and File Locking Capabilities in MS-DOS Version 2.00

PSS ID Number: Q21188 Article last modified on 11-16-1992

2.00 MS-DOS

Summary: File- and record-locking syntax are accepted by the Microsoft COBOL Compiler under MS-DOS Version 2.x, but are ignored at run time. This means that files used in a multi-user environment under MS-DOS Version 2.x are unprotected by MS COBOL. Under MS-DOS Versions 3.10 and later, exclusive file locking for all file types is supported. Record locking also is supported for Relative files. However, record locking for Indexed files is not supported with this release. Regardless of whether record locking is specified for an Indexed file, any Indexed file opened for OUTPUT or I/O will be locked with the Exclusive option. No locking will be done for Indexed files opened for INPUT.

Copyright Microsoft Corporation 1992.