Programming instructions

Intermec Fingerprint 6.13 – Programmer's Guide

7. INPUT TO FINGERPRINT, cont'd.

4. Input from a Sequential

File, cont'd.

When a file is no longer used, it can be closed by means of a CLOSE

statement containing the same reference number as the correspond-

ing OPEN statement. An END statement also closes all open files.

A few instructions facilitate the use of files for sequential input:

EOF (End of File)

The EOF function can connection with the statements INPUT#,

LINE INPUT# and INPUT$ to avoid the error condition "Input past

end". When the EOF function encounters the end of a file, it returns

the value -1 (TRUE). If not, it returns the value 0 (FALSE).

Example:

10 DIM A%(10)

20 OPEN "DATA" FOR OUTPUT AS #1

30 FOR I%=1 TO 10

40 PRINT #1, I%*1123

50 NEXT I%

60 CLOSE #1

70 OPEN "DATA" FOR INPUT AS #2

80 I%=0

90 WHILE NOT EOF(2)

100 INPUT #2, A%(I%):PRINT A%(I%)

110 I%=1+1:WEND

120 IF EOF(2) THEN PRINT "End of File"

RUN

LOC (Location)

The LOC function returns the number of 128-byte blocks, that have

been read or written since the file was OPENed.

This example closes the file "ADDRESSES" when record No. 100

has been read from the file:

10 OPEN "ADDRESSES" FOR INPUT AS #1

.....

200 IF LOC(1)=100 THEN CLOSE #1

.....

LOF (Length-of-File)

The LOF function returns the length in bytes of an OPENed file.

The example illustrates how the length of the file "Pricelist" is

returned:

10 OPEN "PRICELIST" AS #5

20 PRINT LOF(5)

.....

☞

Relational Operators

Also see:

• Chapter 4.9