Some of us unfortunately have to work with multiple databases like Oracle or MySQL. Their respective clients mysql and sqlplus uses "quit" or "exit" to exit sql client.
Oracle's sqlplus uses "quit" or "exit" and MySQL client can be exited using "quit" and "exit" but for compatibility with psql, it also supports "\q" and "\quit".
Postgres psql already support "\q" and "\quit" but I think that could be cool if it supports "exit" and "quit", talking to friends I saw that I am the only that sometimes try to exit psql with "exit'.
The attached patch implements this way to exit psql.