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SAR$ READ
17.2. READ Function/MASM Interface
The SAR$ READ procedures can be called directly from MASM. The SAR$ data
structure definitions and procedure calls are defined by MASM procedures (PROCs).
The element SAR$PROCS contains these PROCs.
17.2.1. READ Packet and Data Area Description
The SAR$ READ function requires a READ packet and data area for the open-input, read,
and close-input calls. The S$ARRPDEF PROC generates the EQUFs defining the READ
packet fields. The word length of the MASM READ packet and data area is at label
SR$PKTWLEN defined by the S$ARRPDEF PROC (the current length is 72 words).
17.2.1.1. Required Information for READ Procedures
The calling program must set the following fields of the READ packet to appropriate
values:
SR$PKTVER
The READ packet data structure version. The current version is equal to the label
SR$CURVER defined by the S$ARRPDEF PROC. SR$PKTVER must not be modified
between calls to the SAR$ READ routine.
SR$FIPADDR
The address of the input file information packet. This packet is supplied by the caller
(see 16.1). Set this field to zero if input is from the runstream.
SR$INPBUF
The address of the input buffer, used to read images from the input file or element.
This field is defined only if input is from an SDF file or element. It is omitted if input
is from the runstream or an alternate READ$ file. Subsection 16.1.2 describes the
input buffer.
SR$INPBUFL
The length in words of the input buffer. It must be of length 28 * dpf * n, where dpf
is the disk prepping factor and n is a positive integer. This field is defined only if
input is from an SDF file or element. It is omitted if input is from the runstream or
an alternate READ$ file.
SR$IMGBUF
The address of the input image buffer into which SAR$ places individual images
from the input buffer. Subsection 16.1.2 describes the image buffer.
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