I'm not at ease with C language, so it is very hard to read.
My intuition is that the readline part operation is applied before the shell variable interpolation, is it correct?
> Is the message in this file: **(those will not be rescanned for more escape sequences!)** is present into the file, to tell that no further interpolation can be performed into both Psql and shell variables?
Thanks in advance for your feedbacks and/or workarounds,