Re: fixing pg_ctl with relative paths

At Fri, 31 Jul 2020 09:42:42 +0800 (CST), ZHAOWANCHENG <zhaowcheng(at)163(dot)com> wrote in
> At 2014-01-28 21:11:54, "Bruce Momjian" <bruce(at)momjian(dot)us> wrote:
> >On Mon, Jul 1, 2013 at 08:10:14PM -0400, Josh Kupershmidt wrote:
> >> On Thu, Jun 27, 2013 at 11:47 AM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> >> > On Thu, Jun 27, 2013 at 10:36 AM, Josh Kupershmidt <schmiddy(at)gmail(dot)com> wrote:
> >> >> On Wed, Jun 26, 2013 at 12:22 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> >> >>> Though this is a corner case, the patch doesn't seem to handle properly the case
> >> >>> where "-D" appears as other option value, e.g., -k option value, in
> >> >>> postmaster.opts
> >> >>> file.
> >> >>
> >> >> Could I see a command-line example of what you mean?
> >> >
> >> > postmaster -k "-D", for example. Of course, it's really a corner case :)
> >>
> >> Oh, I see. I was able to trip up strip_datadirs() with something like
> >>
> >> $ PGDATA="/my/data/" postmaster -k "-D" -S 100 &
> >> $ pg_ctl -D /my/data/ restart
> >>
> >> that example causes pg_ctl to fail to start the server after stopping
> >> it, although perhaps you could even trick the server into starting
> >> with the wrong options. Of course, similar problems exists today in
> >> other cases, such as with the relative paths issue this patch is
> >> trying to address, or a datadir containing embedded quotes.
> >>
> >> I am eager to see the relative paths issue fixed, but maybe we need to
> >> bite the bullet and sort out the escaping of command-line options in
> >> the rest of pg_ctl first, so that a DataDir like "/tmp/here's a \"
> >> quote" can consistently be used by pg_ctl {start|stop|restart} before
> >> we can fix this wart.
> >
> >Where are we on this patch?
> >
> >--
> > Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
> > EnterpriseDB http://enterprisedb.com
> >
> > + Everyone has their own god. +
> >
> >
> >--
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> >
>
>
> Hi, I encountered the same problem.
> I want to know is there a final conclusion?
> thank you very much!

It seems to me agrouding on parsing issue. We haven't find a way to
parse the content of postmaster.opt properly.

1. For escaped option arguments, we can't find where directory name ends.

"-D" "/tmp/here's a \" quote"

2. We need to distinguish option names and arguments.

"-k" "-D" # "-D" is an arguemnt, not a option name.

3. This is not mentioned here, but getopt accepts "merged" (I'm not
sure what to call it.) short options.

"-iD" "/hoge" # equivalent to "-i" "-D" "hoge"

We need to either let pg_ctl reparse the commandline the same way with
postmaster or let postmaster normalize and/or markup the content of
postmaster.opts so that pg_ctl can read it desired way. That can be as
attached, but the change seems a bit too big..

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center