Defining multi-line strings in psql

Question

I would like to paste

  123
  456
  789

into psql and to store multi-line string in some variable (ie. :str) for late

Answer 1

A little clunky, but in version 9.3 and up, you can do it with \gset in conjunction with a dollar-quoted literal:

SELECT
$$123
456
789$$ AS str \gset