Radio Shack TRS-80 model III Owner's Manual page 142

DISK
BASIC
This function
checks
to
see
whether
all
characters
up
to
the end-of-file
marker
have been accessed, so
you
can avoid input past
end
errors
during sequential
input.
Assuming nmexp
specifies
an open
file,
then
EOF(nmexp)
returns (false)
when
the
eof
record has not yet
been
read,
and
-
1
(true)
when
it
has
been
read.
Examples
IF
E0F(5) THEN
PRINTEND
OF
FILE"FILENM*
IF
EOF(NM)
THEN CLOSE
NM'Z
The
following
sequence of
lines
reads
numeric
data
from data/txt
into the
array a(
).
When
the
last
data character in the
file is
read, the
eof
test
in line
30
"passes," so the
program branches out of
the disk
access loop, preventing
an input
past
end
error
from
occurring.
Also note that the variable
i
contains
the
number
of elements input into
array a(
).
5
DIM A<100>
'ASSUMING THIS
IS
A
SAFE VALUE
10
OPEN
"I"
tl
*
"DATA/TXT"
20 11=0
30
IF
E0F(
I
)
THEN
70
40
INPUTtti
tfi(IX)
50
n.=n.+i
S0 GOTO 30
70
REM PROGRAM
CONTINUES HERE AFTER
DISK INPUT
LOC
Get Current Record
Number
file
number
is
a
numeric expression specifying the buffer for
a currently-
opiinrt^
loc
is
used
to
determine the current
record
number,
i.e.,
the
number of
the
last
record read since the
file
was opened,
loc
is
only valid
after
a get.
Example
PRINT LOC(l)
141