The GUD interaction buffer uses a variant of Shell mode, so the commands of Shell mode are available (see section Shell Mode). GUD mode also provides commands for setting and clearing breakpoints, for selecting stack frames, and for stepping through the program. These commands are available both in the GUD buffer and globally, but with different key bindings.
The breakpoint commands are usually used in source file buffers, because that is the way to specify where to set or clear the breakpoint. Here's the global command to set a breakpoint:
Here are the other special commands provided by GUD. The keys starting with C-c are available only in the GUD interaction buffer. The bindings that start with C-x C-a are available in the GUD buffer and also in source files.
gud-step). If the line contains a function call, execution stops after entering the called function.
gud-remove). If you use this command in the GUD interaction buffer, it applies to the line where the program last stopped.
The above commands are common to all supported debuggers. If you are using GDB or (some versions of) DBX, these additional commands are available:
gud-up). This is equivalent to the `up' command.
gud-down). This is equivalent to the `down' command.
If you are using GDB, these additional key bindings are available:
gud-gdb-complete-command). This key is available only in the GUD interaction buffer, and requires GDB versions 4.13 and later.
These commands interpret a numeric argument as a repeat count, when that makes sense.