Group Format Errors

Group Format Errors (GFEs) occur when the item count cannot be verified or when a linking frame error has occurred. Most GFEs can be repaired without much difficulty. Nonetheless, repairing GFEs is a detailed task which you must fully understand before you attempt to do it; if you repair a GFE incorrectly, it can only cause more GFEs.

Whenever a GFE is detected, the GFE Handler, a system subroutine, is called by one of the major file and item processing software routines. The handler detects seventeen types of GFEs and prompts the user to respond. The user can choose to abort the process, to repair the GFE manually, to ignore or automatically correct the error, or to truncate the group containing the error. All errors and responses are logged automatically in the SYSTEM-ERRORS file. If the error occurred during a filesave, the user can complete the filesave by skipping all groups containing GFEs.

How the GFE Handler Works

When a GFE is detected, the handler examines the group containing the GFE from the first frame of the group. This examination proceeds in two passes. First the links are examined both for legal forward links and for backward links. When the last frame in the linked set is reached, two segment marks (X'FF') are put in the last two bytes of this frame and the logical item format analysis begins again at the base of the group. This continues until a double segment mark is found. If neither pass detects anything amiss, a transient GFE (Type 0) is logged—without any CRT display—and the calling processor is re-entered.

Transient GFEs can occur when one or more users attempt to access an item in a group that is being updated by another user. The transient GFE disappears on its own. The user, however, should consider its occurrence as a warning of improper group handling and file sizing.

The following topics are presented in this section:

GFE Types

GFE Handler Prompt and Commands

Using the F (Fix) Command