HP 3000 Manuals HP 3000 Manuals
Including Multi-User Syntax in Your Program This section describes the additional syntax you must include to allow your programs to be run in a shared file environment. You do not have to use program calls to make your files shareable, because file sharing is handled with COBOL syntax. All of the syntax that is used to make data files shareable is an extension to the ANSI 1985 standard X3.23, and this syntax is based on IBM's 8100 DPPX multi-user specification, though it does not implement that specification. All X/Open multi-user features are supported. With the extra syntax you can make data files shareable or lock an entire file. The latter is an exclusive lock which denies access to the file by other operators. Existing programs written using previous Micro Focus COBOL products can be easily modified to make them suitable for use in a shared file environment. If you require the default locking, all you have to do is submit your original source programs to the cob command. For any other kind of locking you must add the required syntax to your source program before submitting it to the cob command. If your program does not already contain a status item then you must declare one in your program, and you must also add any code you require to handle specific status information. When a file status data item is included in your program, whenever the program tries to access a file a status is returned in this data item. From the value in this data item you will know whether the operation was successful or not. See the section Input-Output Error Handling in Chapter 18 , File Status for details.