Getting SQLSTATE in psql error messages I have the following problem.  

SELECT * FROM tgvbn();
ERROR:  function tgvbn() does not exist
LINE 1: SELECT * FROM tgvbn();
                      ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.


Since Appendix A of the official documentation only states error_codes and conditional names but not the actual messages, one can only guess that "No function matches..." refers to 42883 / undefined_function.  I can set log_error_verbosity = verbose in postgresql.conf - but that will affect the logs, not the messages returned to the client:


  Controls the amount of detail written in the server log for each
  message that is logged.


Well, I can consult the logs for this piece of information, but is there any means of including it in the error messages?
Based on a_horse_with_no_name's comment, I started searching around psql and found the solution:

\set VERBOSITY verbose
SELECT * FROM tgvbn();

ERROR:  42883: function vfjkb() does not exist
...


Now that goes into .psqlrc.  Details and further options can be found in the psql documentation.