Radio Shack TRS-80 model III Owner's Manual page 137

H
TRS-80
MODEL
III
DISK
SYSTEM
Often
you'll
want
to
use a
dummy
variable
in a
field statement
to
"pass
over"
a portion of
the buffer
and
start
fielding
it
somewhere
in
the middle.
For example:
FIELD
It 1G
AS CLIENT$(l)t
112 AS
HIST*<1>
FIELD
it
128 AS
DUMMY**
1G
AS CLIENT$(2),
112 AS HIST$(2)
In the
second field
statement,
dummys
serves
to
move
the starting position of
client$(2)
to
position 129. In
this
manner, two
identical
"subrecords"
are
defined
on
buffer
number
1
.
We
won't
actually use
dummy$
to
place data
into
the
buffer or
retrieve
it
from
the buffer.
The
buffer
now
looks
like
this:
16 112
16 112
CL$
d)
HIST$
(D
CL$
(2)
HIST$
(2)
DUMMY$
GET
Read
a
Record from
Disk-
Random
Access
get
mexpti;!imxp2i
'
into^
15.
nmexp2
specifies
which
record
to
get
in
the
lite;
if
omitted, the current
record
will
be
read.
This statement
gets
a data record from
a disk
file
and
places
it
in the specified
buffer.
Before GETting
data
from
a
file,
you must open
the
file
and
assign a
buffer
to
it.
That
is,
a statement
like:
open
u
R" ,nmexpl
filespec
is
required before
the statement:
get nmexpl
y
nmexp2
get
tells
basic
to
read record
nmexp2 from
the
file
and place
it
into the
nmexpl
buffer.
If
you omit
the record
number
in
get, basic
will
read
the current record.
136