# System Functions

KEF( ) | Return First Key of File

## Format

KEF(chan[,fileopt])
Where:

chan | Channel or logical file number of the file to reference.
fileopt | Supported file options (see File Options):
END=stmtref | End-of-File transfer
ERR=stmtref | Error transfer
KNO=num | string$ | File access key number (num) or name (string$)
stmtref | Program line number or statement label to which to transfer control.

## Returns

Key of first record in file.

## Description

The KEF( ) function returns the key of the first record in the file specified. The result is based on the:

- Current file access key or
- Access key specified using the KNO= option

The KEF( ) function can also be used in TCP (Transmission Control Protocol) to identify local sockets.

## See Also

File Handling

## Example

open (1) "CUSTNO"
......
F$=kef(1),L$=kel(1)
print "Customers range from ",F$,"->",L$
......
end