HP 3000 Manuals HP 3000 Manuals
VREADBATCH
Reads contents of current batch record into data buffer in memory.
Syntax
VREADBATCH {comarea}
Parameters
comarea Must be comarea name used when the batch file was opened
with VOPENBATCH. If not already set, the following
comarea items must be set before calling VREADBATCH:
cstatus Set to zero.
comarealen Set to total number of two-byte words
in comarea.
recnum Set to the number of the record in the
open batch file from which data is to
be read (records are numbered from
zero).
VREADBATCH may set the following comarea items:
nfname Set to the name of the form associated
with the data read from the batch file
(used by VGETNEXTFORM to retrieve this
form from forms file).
dbuflen Set to length of data buffer (in bytes)
based on length of data read from batch
record.
deleteflag Set to TRUE (all ones) if delete flag
in batch record indicates record is
deleted; set to FALSE (all zeros)
otherwise.
cstatus Set to nonzero value if call
unsuccessful.
filerrnum Set to file error code if MPE file
error.
Discussion
Use of this intrinsic is demonstrated by the browse/modify mode of ENTRY.
It enables a user to view the data in the batch file. VREADBATCH may
also be used to bring the data from a batch file into the data buffer so
that it can be retrieved by an application with the VGETBUFFER,
VGETFIELD, or VGETtype intrinsics.
To display the data just read onto its associated form, VGETNEXTFORM must
be called before the call to VSHOWFORM.
VREADBATCH reads the record (recnum) in the batch file opened by
VOPENBATCH. The record is read into memory, where VREADBATCH extracts the
batch record control information (refer to the VOPENBATCH description).
This information includes the current form name which is moved to nfname,
the delete flag which is moved to deleteflag, and the data length in
bytes which is moved to dbuflen. The data buffer is not updated if the
deleteflag has been set.
In order to use VREADBATCH, the batch file must be on a direct-access
device and must be created with fixed-length records, not variable-length
records.
Example
COBOL
CALL "VREADBATCH" USING COMAREA.
BASIC
175 CALL VREADBATCH(C(*))
FORTRAN
CALL VREADBATCH(COMAREA)
SPL/PASCAL
VREADBATCH (COMAREA);
The calls shown above read the batch record specified by recnum update
the comarea according to the batch record information stored with the
data, and put the data in the data buffer in memory.