Overflow Routine

Figure 9 shows the specific steps in the RPG IV overflow routine. The item numbers in the following descriptions refer to the numbers in the figure.

 1 

The RPG IV program determines whether the overflow lines were written previously using the fetch overflow logic (step 30 in Figure 8). If the overflow lines were written previously, the program branches to the specified return point; otherwise, processing continues with step 2.

 2 

All output lines conditioned with an overflow indicator are tested and written to the conditioned overflow lines.

The fetch overflow routine allows you to alter the basic RPG IV overflow logic to prevent printing over the perforation and to let you use as much of the page as possible. During the regular program cycle, the RPG IV program checks only once, immediately after total output, to see if the overflow indicator is on. When the fetch overflow function is specified, the RPG IV program checks overflow on each line for which fetch overflow is specified.

Specify fetch overflow with an F in position 18 of the output specifications on any detail, total, or exception lines for a PRINTER file. The fetch overflow routine does not automatically cause forms to advance to the next page.

During output, the conditioning indicators on an output line are tested to determine whether the line is to be written. If the line is to be written and an F is specified in position 18, the RPG IV program tests to determine whether the overflow indicator is on. If the overflow indicator is on, the overflow routine is fetched and the following operations occur:

• Only the overflow lines for the file with the fetch specified are checked for output.
• All total lines conditioned by the overflow indicator are written.
• Forms advance to a new page when a skip to a line number less than the line number the printer is currently on is specified in a line conditioned by an overflow indicator.
• Heading, detail, and exception lines conditioned by the overflow indicator are written.
• The line that fetched the overflow routine is written.
• Any detail and total lines left to be written for that program cycle are written.

Position 18 of each OR line must contain an F if the overflow routine is to be used for each record in the OR relationship. Fetch overflow cannot be used if an overflow indicator is specified in positions 21 through 29 of the same specification line. If this occurs, the overflow routine is not fetched.

Use the fetch overflow routine when there is not enough space left on the page to print the remaining detail, total, exception, and heading lines conditioned by the overflow indicator. To determine when to fetch the overflow routine, study all possible overflow situations. By counting lines and spaces, you can calculate what happens if overflow occurs on each detail, total, and exception line.