The TUI also provides a SingleKey mode, which binds several frequently used GDB commands to single keys. Type C-x s to switch into this mode, where the following key bindings are used:
nexti. The shortcut letter ‘o’ stands for “step Over”.
exit the SingleKey mode.
stepi. The shortcut letter ‘i’ stands for “step Into”.
Other keys temporarily switch to the GDB command prompt. The key that was pressed is inserted in the editing buffer so that it is possible to type most GDB commands without interaction with the TUI SingleKey mode. Once the command is entered the TUI SingleKey mode is restored. The only way to permanently leave this mode is by typing q or C-x s.