Re: Explicit psqlrc

On Jul 21, 2010, at 12:31 PM, Alvaro Herrera wrote:

> Excerpts from Peter Eisentraut's message of mié jul 21 10:24:26 -0400 2010:
>> On tis, 2010-07-20 at 11:48 -0400, Robert Haas wrote:
>>> It's tempting to propose making .psqlrc apply only in interactive
>>> mode, period.  But that would be an incompatibility with previous
>>> releases, and I'm not sure it's the behavior we want, either.
>>
>> What is a use case for having .psqlrc be read in noninteractive use?
>
> Even if there weren't one, why does it get applied to -f but not -c?
> They're both noninteractive.


So not to let the thread drop, it appears that we're faced with the following situation:

1) The current behavior is inconsistent with the psqlrc handling of -c and -f.
2) The current behavior is still historical and we presumably want to maintain it.

I'm not sure of the cases where we're willing to break backwards compatibility, but I do know that it's not done
lightly. So perhaps for this specific patch, we'd need/want to punt supporting both -c's in conjunction with -f's, at
leastuntil we can resolve some of the ambiguities in what the actual behavior should be in each of these cases.  This
couldstill be a followup patch for 9.1, if we get these issues resolved. 

And as long as we're redesigning the bike shed, I think a better use case for supporting multiple sql files would be to
supportthem in such a way that you wouldn't need to provide explicit -f flags for each.  Many programs utilize the '--'
tokenfor an "end of options" flag, with the rest of the arguments then becoming something special, such as filenames.
Sowhat about adding the interpretation that anything after '--' is interpreted as a filename?  That will allow the use
ofshell wildcards to specify multiple files, and thus allow something like: 
 $ psql -U myuser mydatabase -- *.sql $ psql -- {pre-,,post-}migration.sql

while still being unambiguous with the current convention of having an unspecified argument be interpreted as a
databasename.  This would make it possible to actually specify/use multiple files in a fashion that people are used to
doing,as opposed to having to explicitly type things out or do contortions will shell substitutions, etc. 

Regards,

David
--
David Christensen
End Point Corporation
david@endpoint.com