From Bash's manual (Controlling the Prompt]1):
\j the number of jobs currently managed by the shell. \$ If the effective uid is 0, #, otherwise $.
What I'd like is to set
when there are no jobs; and
when there are 2 jobs.
How I could I achieve that?
If possible, the solution could be simple, with only basic Bash expansions and possibly Bash builtins.