Texas Instruments TI-99/4A - Page 148

INPUT
Using Pending Inputs
A
pendmg mput conditIOn IS established when an INPUT statement
with a trailing comma is performed. When the next INPUT
statement using that file is encountered. one of the following actions
will occur:
• If the next INPUT statement has no REC clause - the
computer uses the data in the 110 buffer beginning where
the previous INPUT statement stopped .
• If the next INPUT statement includes a REC clause -
the computer terminates the pending input condition and
reads the specified record into the file's I/O buffer.
If a pending input condition exists and a PRINT statement for the
same file is performed, the pending input condition is terminated
and the PRINT statement is performed as usuaL
If you use a pending input with fife-number 0, the error message
"INCORRECT STATEMENT" is printed and the program stops
runmng.
End-of-file
In sequential processing, to prevent an error when the computer
has no more data to read, you will need to notify the computer that
the end of the file has been reached. To make this easier for you. TI
BASIC includes an End-of-File function called EOF. Be sure to
include the
EOF statement immediately before the INPUT
statement which reads a sequential file. In this way you can
easily cause the computer to stop reading the input file when no
more data is available. The usual procedure is to skip to a
closing routine when EOF is reached
II·t2H
Examples:
>NEW
>100 INPUT #O:A,B,
>110 PRINT A;B
>120 GOTD 100
>RUN
?
* INCORRECT STATEMENT
IN 100
>NEW
>100 OPEN #5:NAME$,SEQUENTIAL
,INTERNAL,INPUT,FIXED
>110 IF EOF(S)
THEN 150
>120 INPUT #S~A,B
>130 PRINT A;B
>140
GOTO 710
>150
CLOSE #5
>160 END
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