Typical Errors in COBOL Applications

Typical Errors

Some kinds of potential errors are common to many COBOL programs. In almost every case, these conditions should cause the program to abort. Even the exceptions usually deserve a warning message.

Input File Errors

Empty file

Missing header

Missing trailer

Wrong record count on trailer

No data between header and trailer

Wrong sort sequence

Cycle error

Invalid record type

Faulty structure; e.g. multiple record types which must reflect some kind of hierarchical arrangement

Output File Errors

No data to write, except maybe for header and trailer

Out of space -- especially on a small machine like a PC (thanks to Dave Demaree for reminding me of this one)

Working Storage Table Errors

Table overflow

Empty table

Invalid data

Internal Errors

Invalid parameter passed to subprogram

Nonsensical sequence of calls to subprogram (e.g. trying to read a file after closing it)
Fatal error reported by subprogram

Invalid status code returned by subprogram

Inability to allocate enough memory

Corrupted data structures

Unexpected selection of default in a case structure (e.g. WHEN OTHER in an EVALUATE statement)

Unexpected return code from IMS or some other subsystem

Any inconsistency indicating the presence of a program bug

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