dread - read record using record number
rno_t dread (buf, record, fcb)
Dread reads the record stored at the record number specified by
record, where record is between 1 and number of records in the
RMSfile. Record is returned by all calls that access the RMSfile.
Fcb is the file block pointer returned by dlopen(C-3) or
Chapter 4, RMS Programming Guide
Dread returns a value of BAD (-1) if record is not within the
range of valid records for the RMSfile, if no record has been
written at the record number specified or if fcb is not an
opened file block pointer.