The replay command is a combination command, equivalent to issuing a save -1 followed immediately by a restore. The replay command takes a negative number argument, which it passes to the save portion of the command. By default, the value of -number is -1, so the replay command works as an undo command, restoring the last run until,but not including the last command issued.
To rep lay the current debugging run, minus the last debugging command issued, type:
(dbx) replay
To replay the current debugging run and stop the run before a specific command, use the –number option, where number is the number of commands back from the last debugging command.
(dbx) replay -number