Reading History Records

A binary file may have two groups of variables: those belonging to a set of history records, and non-record variables. The record variables may have different values in each record. The records are labeled by (optional) time and cycle numbers:

jt, time      advance all open record files to record nearest time
jt, f, time   advance file f to record nearest time
jc, f, ncyc   advance file f to record nearest ncyc
get_times(f)  return list of record times
get_ncycs(f)  return list of record cycles