Using the source line numbers

The line numbers in the source are used. In the case of a copy operation, these are the lines to be copied from another work file.
When data is read from a file then, in the case of ISAM files, the line numbers are formed from the ISAM key (unless specified to the contrary). In the case of SAM files with the KEY operand specified, the first eight characters of each record are interpreted as the line number.
Any lines with the same line numbers present in the target file are overwritten. The new current line number is formed from the line number of the last line plus the current increment if the line number of the last line has changed. Otherwise it remains unchanged.

The following table indicates the EDT statements for which this procedure is used (in the case of some EDT statements, other procedures may be used in the event of a different format or different operands).

Statement	Comments on operands	General comments
@COPY Format 1	Read in ISAM files with operand specification KEY=LINENUMBER
@COPY Format 2	No target specification
@GET	With operand specification NORESEQ
@MOVE	No target specification
@ON Format 4 + 5	With operand specification KEEP	If the OLD operand is not specified then the target work file is deleted before insertion.
@OPEN Format 1	Open ISAM files with operand specification KEY=LINENUMBER	The work file must be empty before the statement is executed.
@OPEN Format 2	Open a copy of SAM files with specification of KEY operand and open a copy of ISAM files	The work file must be empty before the statement is executed. If a file is already opened with the @OPEN statement (format 2) and a new @OPEN statement (format 2) is issued then the second @OPEN statement is implicitly preceded by a @CLOSE statement, i.e. the work file is implicitly deleted.
@READ	With specification of the KEY operand