Thread: Remove readline notice from psql --version?
Currently, psql --version prints something like psql (PostgreSQL) 9.2beta1 contains support for command-line editing I think the notice about readline is a leftover from the old days when psql was often built without any readline support. Nowadays, this looks like an anomaly, and it doesn't actually contain any information that would be useful nowadays, such as which particular library is used or what kind of history support is active. I suggest we remove this second line, or alternatively, we could add more useful detail, but what?
Peter Eisentraut <peter_e@gmx.net> writes:
> Currently, psql --version prints something like
> psql (PostgreSQL) 9.2beta1
> contains support for command-line editing
> I think the notice about readline is a leftover from the old days when
> psql was often built without any readline support. Nowadays, this looks
> like an anomaly, and it doesn't actually contain any information that
> would be useful nowadays, such as which particular library is used or
> what kind of history support is active. I suggest we remove this second
> line, or alternatively, we could add more useful detail, but what?
Hm, I had actually forgotten that was there. When the question of
"which readline library does this use?" has come up in the past,
we've always been able to get an answer from ldd or local equivalent.
I suppose that could fail in the case of statically linked libraries,
but the practical use for the message seems about nil. I'm good with
just removing it.
regards, tom lane
On Sun, May 20, 2012 at 01:24:21AM +0300, Peter Eisentraut wrote: > Currently, psql --version prints something like > > psql (PostgreSQL) 9.2beta1 > contains support for command-line editing I think this should be replaced with a notice about the actual library used. Cheers, David. -- David Fetter <david@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fetter@gmail.com iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate
Excerpts from David Fetter's message of dom may 20 15:30:52 -0400 2012: > On Sun, May 20, 2012 at 01:24:21AM +0300, Peter Eisentraut wrote: > > Currently, psql --version prints something like > > > > psql (PostgreSQL) 9.2beta1 > > contains support for command-line editing > > I think this should be replaced with a notice about the actual library > used. That was my thought as well, but is it possible to implement it? -- Álvaro Herrera <alvherre@commandprompt.com> The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support
Alvaro Herrera <alvherre@commandprompt.com> writes:
> Excerpts from David Fetter's message of dom may 20 15:30:52 -0400 2012:
>> I think this should be replaced with a notice about the actual library
>> used.
> That was my thought as well, but is it possible to implement it?
And, more to the point, would it be more reliable than checking the
results of system-specific tools such as ldd?
regards, tom lane
Excerpts from Tom Lane's message of dom may 20 23:04:59 -0400 2012: > > Alvaro Herrera <alvherre@commandprompt.com> writes: > > Excerpts from David Fetter's message of dom may 20 15:30:52 -0400 2012: > >> I think this should be replaced with a notice about the actual library > >> used. > > > That was my thought as well, but is it possible to implement it? > > And, more to the point, would it be more reliable than checking the > results of system-specific tools such as ldd? If well implemented, my guess is that it would be. For example recall that in Debian they are shipping psql linked to libedit due to licensing concerns, but then suggest a hack to use LD_PRELOAD to load libreadline instead. So ldd might tell you that it's linked to libedit and fail to notice that at runtime something different is being used. -- Álvaro Herrera <alvherre@commandprompt.com> The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support
Alvaro Herrera <alvherre@commandprompt.com> writes:
> Excerpts from Tom Lane's message of dom may 20 23:04:59 -0400 2012:
>> And, more to the point, would it be more reliable than checking the
>> results of system-specific tools such as ldd?
> If well implemented, my guess is that it would be. For example recall
> that in Debian they are shipping psql linked to libedit due to licensing
> concerns, but then suggest a hack to use LD_PRELOAD to load libreadline
> instead. So ldd might tell you that it's linked to libedit and fail to
> notice that at runtime something different is being used.
[ raised eyebrow ... ] Yeah, but exactly what would it take to produce
an output that told the truth in such a situation? I'll bet a large
amount of money that you would need a separate implementation for every
platform. And this problem just is not worth that.
regards, tom lane