GDB indicates its readiness to read a command by printing a string called the prompt. This string is normally ‘(gdb)’. You can change the prompt string with the set prompt command. For instance, when debugging GDB with GDB, it is useful to change the prompt in one of the GDB sessions so that you can always tell which one you are talking to.
Note:
set prompt
no longer adds a space for you after the prompt you set. This allows you
to set a prompt which ends in a space or a prompt that does not.