Messages are output to an error log. There are situations in which the return value of a function is not enough to determine the cause of an error and resolve the problem. In such a case, examine the error log, as it may contain messages that will allow you to determine the cause of the error.

An error log is usually output to the CUP executing directory. However, when you specify DCTRCPATH in the client environment definition, the error log is output to the directory specified by DCTRCPATH. No error log is output when the specified directory does not exist.

Whether error logging is used depends on the specification of DCTRCERR in the client environment definition. If you omit the specification of DCTRCERR, or specify DCTRCERR to output an error log, two files (dcerr1.trc and dcerr2.trc) are created. When there is no information to be output, no file is created.

The two files are switched in accordance with the round-robin method, and are output chronologically. Thus, old information is deleted in units of files. If a write exceeds the file size specified for DCTRCERR in the client environment definition, the files are switched. If a write does not exceed the specified file size at the beginning of the write, the information is output. Thus, the actual file size may be greater than the specified file size.

Note that the character string output at the beginning of a file is maintenance information.