Programming instructions

Intermec Fingerprint v7.61 – Programmer’s Reference Manual Ed. 7 157

Chapter 2 Program Instructions

LOC

Field of Application

Function returning the current position in an OPEN ﬁ le or the status of

the buffers in an OPEN communication channel.

Syntax LOC(<nexp>)

<nexp> is the number assigned to the ﬁ le or communication channel

when it was OPENed.

Remarks

In a random ﬁ le, LOC will return the number of the last record read or written

by the use of GET or PUT statements respectively.

In a sequential ﬁ le, the number of 128-byte blocks, that have been read or

written since the ﬁ le was OPENed, will be returned.

LOC can also be used to check the receive or transmit buffer of the speciﬁ ed

communication channel:

• If the channel is OPENed for INPUT, the remaining number of characters

(bytes) to be read from the receive buffer is returned.

• If the channel is OPENed for OUTPUT, the remaining free space (bytes)

in the transmit buffer is returned.

The number of bytes includes characters that will be MAPped as NUL.

Examples

This example closes the ﬁ le "addresses" when record No. 100 has been

read from the ﬁ le:

10 OPEN "ADDRESSES" FOR INPUT AS #1

.....

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

.....

This example reads the number of bytes which remains to be received from

the receive buffer of "uart2:":

100 OPEN "uart2:" FOR INPUT AS #2

110 A%=LOC(2)

120 PRINT A%