The following syntax describes how to form absolute and relative references to generation data groups (GDGs) and generation files.
GDG and GDS syntax >>-gdgBaseName-+------------------------+---------------------->< +-.gxxxxvyy--------------+ '-(--+-*------------+--)-' +-+-----+--mmm-+ | '- - -' | '- +nnnn-------'
gdgBaseName can be any valid file name. However, avoid specifying a base name that looks like an absolute or relative reference, for example, my(+1)Base.
An absolute name is thus of the form gdgBaseName.gxxxxvyy.
A reference to the entire group is of the form gdgBaseName(*) or gdgBaseName.
It is an error to refer to a nonexistent generation.
A relative name for an existing generation is thus of the form gdgBaseName(mmm) or gdgBaseName(-mmm).
A number greater than 1 can cause generation numbers to be skipped. For example, if only one generation exists and gdgBaseName(+3) is specified, two generations are skipped.
It is not an error to open for input a reference such as gdgBaseName(+1234) if the reference resolves to an existing file in the group.
related concepts
Generation data groups
related tasks
Using generation data groups
related references
Insertion and wrapping of generation files
File specification