Re: Slightly better testing for pg_ctl(1)'s -w...

Sean Chittenden <chitt(at)speakeasy(dot)net> writes:
> pg_ctl(1)'s -w option works well if the default user can automatically
> authenticate without any user intervention. The attached patch checks
> the error message to see if it's asking for a password. The theory
> being that if it's asking for a password, the backend is up. I'm not
> entirely happy with the fact that I'm dependent on the error message
> text, but I couldn't easily figure out a better way to test this via
> libpq(3), so I'm not too unhappy... it's just not elegant.

psql and pg_dump test for this same error string, so you're in good
company on that front, but password prompting is not the only or even
the most likely misleading failure. I believe both the Red Hat and
Debian distributions set the default auth method to IDENT, meaning that
the message you'd likely get is going to be a bleat about IDENT auth
failing, not a password request. Unfortunately that message is going to
be localized, but it should have a SQLSTATE assigned, so you could
check for ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION ...

regards, tom lane