Re: review: psql: edit function, show function commands patch

On Mon, Aug 2, 2010 at 11:17 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Mon, Aug 2, 2010 at 10:49 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> I'm tempted
>>> to suggest forgetting about any user-configurable parameter and just
>>> provide code that strcmp's the $EDITOR value to see if it recognizes the
>>> editor name, otherwise do nothing.
>
>> With all due respect, that sounds like an amazingly bad idea.  Surely,
>> we'll be forever getting patches to add $MYFAVORITEEDITOR to the list,
>> or complaints that it's not already included.
>
> Well, yeah, that's the idea.  I say that beats a constant stream of
> complaints that $MYFAVORITEEDITOR no longer works at all --- which
> is what your concern was, no?

Well, it'd still work fine for \e foo. It'll just blow up for \e foo
3. My concern isn't really that things that which work now will break
so much as that this new feature will fail to work for a large
percentage of the people who try to use it, including virtually
everyone who tries to use it on Win32.

>> While this is
>> superficially a Nice Thing to Have and I would certainly support it if
>> +linenumber were relatively universal, it's really a pretty minor
>> convenience when you come right down to it, and I am not at all
>> convinced it is worth the hassle of trying to divine what piece of
>> syntax will equip the user's choice of editor with the necessary
>> amount of clue.
>
> The other approach we could take is that this whole thing is disabled by
> default, and you have to set a psql variable EDITOR_LINENUMBER_SWITCH
> to turn it on.  If you haven't read the documentation enough to find
> out that variable exists, well, no harm no foul.

That might be reasonable. Right now the default behavior is to do
+line on Linux and /line on Windows. But maybe a more sensible
default would be to fail with an error message that says "you have to
set thus-and-so variable if you want to use this feature". That seems
better than sometimes working and sometimes failing depending on what
editor the user has configured.

A side question is whether this should be an environment variable or a
psql variable.

--
Robert Haas
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