SETUNDO—Set the UNDO Mode

The SETUNDO primary command determines whether the UNDO command is available and how the history of changes should be managed.

Note: The SETUNDO command is ignored if UNDO from storage is not enabled by the installer or person who maintains the ISPF product. For information on enabling UNDO from storage, see z/OS ISPF Planning and Customizing.

Syntax


                .-STORAGE-.   
>>-+-SETUNDO-+--+---------+------------------------------------><
   '-SETU----'  +-KEEP----+   
                +-RECOVER-+   
                +-ON------+   
                '-OFF-----'

STORAGE: Enables the saving of edit changes in storage. If the setting is changed, and the profile lines are displayed, the profile lines show the value (SETUNDO STG) after the change. Valid abbreviations for STORAGE are STO, STG, STOR and STORE.
KEEP: Has the same effect as STORAGE except the UNDO buffers are not cleared when a SAVE is issued.
Note: The effect of KEEP (UNDO buffers not cleared when a SAVE is issued) ceases if SETUNDO is subsequently issued without the KEEP keyword.
RECOVER: Enables the saving of edit changes through the recovery file only. If recovery is off, it is turned on by this command. If the setting is changed and the profile lines are displayed, the profile lines show the value (SETUNDO REC) after the change. A valid abbreviation for RECOVER is REC.
ON: The same as STORAGE.
OFF: Disables the saving of edit changes in storage. If SETUNDO OFF is specified and recovery is on, then a state of SETUNDO RECOVER is set and UNDO is available from the recovery file. All transactions on the storage UNDO chain are removed, and no changes before SETUNDO OFF can be undone (unless RECOVERY ON is specified). If the setting is changed and the profile lines are displayed, the profile lines show the value (SETUNDO OFF or SETUNDO REC) after the change.

Description

SETUNDO allows you to specify how changes you make during your edit session are to be recorded and used by the UNDO command. UNDO can be run when either SETUNDO or RECOVERY is on. Changes can be recorded in storage, in the recovery file, or in both places. Saving the changes in storage only is the fastest method.

To enable recording in storage:

On the command line, type one of these commands:
- ```
SETUNDO STORAGE
```
- ```
SETUNDO KEEP
```
- ```
SETUNDO
```
Press Enter.

The value of ON is accepted to complement the OFF state.

To use the recovery file:

On the command line, type:
```
SETUNDO RECOVER
```
Press Enter.

If RECOVERY is off, it is turned on by this command.

To turn off recording and disable the UNDO command, enter:

SETUNDO OFF

Note: If recovery is on, setting SETUNDO OFF is the same as specifying SETUNDO REC, and the recovery file is used for UNDO.

Examples

The edit profile shown in Figure 1 shows SETUNDO set to STORAGE and RECOVERY OFF.

Figure 1. SETUNDO STORAGE and RECOVERY OFF