# System Functions

KEP( ) | Return Prior Record's Key

## Format

KEP(chan[,fileopt])

Where:

chan | Channel or logical file number of your given file.
fileopt | Supported file options (see File Options):
END=stmtref | End-of-File transfer
ERR=stmtref | Error transfer
KEY=string$ | Record key
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 the prior record in file.

## Description

The KEP( ) function returns the key of the record prior to the record in the file specified. The result is based on the:

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

If the current record is at the start of the file, there is no prior record. PxPlus reports Error #2: END-OF-FILE on read or File full on write unless you include an ERR= or END= option.

The system also supports the KEP( ) function for ODBC and many other database file types.

If the '+K' system parameter is not enabled, the 'Record Key' specified must exist on the file.

## See Also

File Handling

## Example

0010 open (13)"CUSTNO"
0020 read (13,key="zzz",dom=0030) ! Go to end of file
0030 let K$=kep(13,end=1000)
0040 read (13,key=K$)R$
0050 print "Key: ",K$," Data: ",R$
0060 goto 0030
1000 print "Back to the start"
1010 end