Appendix 3: Error and Warning/Information Conditions

Appendix 3: Error and Warning/Information Conditions

The use of the Database Interface Routines is controlled by a system of internal error checks. Incorrect usage of, or input to, the routines will result in an error or warning/information message and usually an error code. The message is output on channels IUMES1 and IUMES2 (see DIINI), and the error code is returned as one of the parameters in the routine which detected the problem. Warning/information messages are not accompanied by an error code.

All messages are presented in the same fixed format which takes the form of a single line of 80 characters. The first two characters are always 'DI'. The next three characters duplicate the error code (IEXIT) which is output by the subroutine detecting the error. The first digit of the error code indicates the severity of the error; this may be 0, 1 , or 2. For warning/information messages characters 3, 4, and 5 are always blank. The error severity number describes the action required to correct the problem.

Warning/information messages require no corrective action. For error codes 001 to 099 routine DIERR need not be called unless the user program specifically requires; the routine causing the error may be called again with changed input, or ignored, depending on the particular problem. For error codes 101 to 199 routine DIERR must be called with ILEVEL = 1 before proceeding. For error codes 201 to 299 routine DIERR must be called with ILEVEL = 2 before proceeding.

Characters 10 to 14 of the error message contain the name of the Database Interface Routine which has detected the error.

Characters 18 to 67 of the error message contain a short piece of text describing the nature of the error.

Characters 71 to 80 of the error message are reserved for supplementary information relating to the error. This field will either contain nothing, a text string, or an integer.

All error, warning, and information messages are routed through a callable Database Interface Routine named DIFMT. Program developers wishing the messages to conform to their own style should re-write this routine to intercept and reformat the messages. A listing of routine DIFMT as it is initially supplied is provided at the end of this Appendix.

The following pages of this Appendix contain a list of all error and warning/information messages that the Database Interface Routines might produce. Some of the error messages may be produced by more than one routine, some may be produced by only one routine. Not all error messages will have supplementary information in the last field.