Command History, REDO

System Debug maintains a very short history of command lines in the form of a stack. Commands in the stack can be displayed with the HIST (or LISTREDO) command, and may be reexecuted with the DO command or edited prior to reexecution with the REDO command.

Commands read from outer level or interactive input are pushed onto the history stack. Currently, commands read from USE files are also pushed onto the stack. Commands executed as part of macro commands are not pushed.