The user can formulate a condition with job variables and constants in the ADD-CJC-ACTION, SKIP-COMMANDS and WAIT-EVENT commands, and in the ONEVT macro. Simple conditions can be combined to form complex conditions by means of logical operators.
The effect of the command depends on the status of the condition in each case (“satisfied” or “not satisfied”). Changes in this condition status are caused by events, i.e. changes in the values of the job variables specified there. The system informs the appropriate job of every event relevant to the condition (e.g. a MODIFY-JV command for a job variable used in the condition). The condition is evaluated and, if it is “satisfied”, the actions provided for this case are carried out. The value change can be carried out by any job which possesses the appropriate access rights for the user job variable. Special job variables which are only permissible in conditions of the SKIP-COMMANDS command can only be changed by the system (e.g. date or time).
The order in which the user job is informed of events determines the order in which the events are processed within the job (i.e. the order of condition analyses). It is not possible to inform jobs of the creation of job variables. This means that conditional commands whose job variables do not yet exist are rejected. On the other hand, existing conditional
commands or macros become invalid if the catalog containing the JV is definitively exported, or if the conditions are explicitly deleted by means of the REMOVE-CJC-ACTION command or the DONEVT macro.