postgres: could not access the server configuration file "/var/lib/postgresql/data/postgresql.conf": No such file or directory code example

Example: psql: error: could not connect to server: could not connect to server: no such file or directory

psql: could not connect to server: No such file or directory

Is the server running locally and accepting connections on 
Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?