Using KSAM/XL and KSAM 64 (32650-90886)

Chapter 5 53

Reading File Data

Sequential Access in Physical Record Order

A sequential access in physical record order is really a series of random accesses by

physical record number. The FPOINT and FREADC intrinsics are used to read records in

order of their physical location in the ﬁle. The FPOINT intrinsic sets the physical record

pointer to the position speciﬁed in its record number parameter. The FREADC intrinsic

reads the record speciﬁed by the physical record pointer without reference to the logical

record pointer. A subsequent FREADC intrinsic advances the physical record pointer to the

next physical record. Any record containing a delete ﬂag is ignored and is not read.

The FREADDIR intrinsic also reads ﬁles in physical record order. It positions the pointer to

the record speciﬁed in the record number parameter. A subsequent FREADDIR intrinsic call

repositions the physical record pointer to the next physical record. Note that deleted

records are not ignored with this intrinsic. It is recommended, therefore, that you use the

FPOINT and FREADC intrinsics to read records sequentially in physical record order. Use the

FREADDIR intrinsic only to read a single record identiﬁed by its physical record number.

The FGETINFO intrinsic returns the physical record pointer setting, as well as other

information, for the record most recently accessed. This number is returned in the record

pointer parameter and can be used in a subsequent FPOINT or FREADDIR intrinsic call.