Date: Mon, 19 Aug 2024 20:06:23 -0400
From: Bruce Momjian <bruce@momjian.us>
To: marc@msys.ch, pgsql-docs@lists.postgresql.org
Subject: Re: Documentation of .pgpass for Unix is incomplete
Message-ID: <ZsPd_1ahHdqcQjgA@momjian.us>
References: <172311029184.915368.14898011794686876553@wrigleys.postgresql.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: 
 <172311029184.915368.14898011794686876553@wrigleys.postgresql.org>
Archived-At: 
 <https://www.postgresql.org/message-id/ZsPd_1ahHdqcQjgA%40momjian.us>
Precedence: bulk

On Thu, Aug  8, 2024 at 09:44:51AM +0000, PG Doc comments form wrote:
> The following documentation comment has been logged on the website:
> 
> Page: https://www.postgresql.org/docs/16/libpq-pgpass.html
> Description:
> 
> The documentation of the .pgpass password file is incomplete in the Unix
> case (https://www.postgresql.org/docs/16/libpq-pgpass.html):
> 
> It does not mention how the .pgpass File is actually found.  One would
> assume it uses the getpwent() function to find the current users
> homedirectory and locate the .pgpass file there, but this is not the case. 
> It only looks at the HOME environment variable.
> 
> If you change the user using setuid() and do not change HOME as well, the
> file not be found.  Or assume you start a DB client as root by using su to
> change the user id, things will not work:
> 
> # /bin/su -c "startx -- " - xpos
> 
> This starts X11 and changes to the user xpos, but it does only change the
> user id, not $HOME.

Well, it is more complicated than checking just HOME because it calls
getpwuid_r() if HOME is not set:

	https://doxygen.postgresql.org/fe-connect_8c.html#a3f49cbb20595c1765bd0db5ff434c9c3

Is it worth going into that detail in the docs?

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Only you can decide what is important to you.