On Fri, Aug 17, 2012 at 06:55:14PM +0100, Richard Huxton wrote: > >Well, it'd be nice to allow substitution there ... > > > >>What we can't easily do is to allow quotes to prevent variable > >>substitution in these whole-line commands because we can't process the > >>quotes because that will remove them. > > > >... but if there is then no way to prevent it, that's absolutely > >unacceptable. > > If I'm understanding this correctly, \copy parsing just passes the > query part unaltered as part of a COPY statement back into the > top-level parser. Likewise with the \!shell stuff (but presumably to > execve). > > To handle variable-substitution correctly for \copy we'd need to > duplicate the full parsing for COPY. For \! we'd need something > which understood shell-syntax (for the various shells out there). > Ick. > > Or you'd need a separate variable-bracketing {{:x}} syntax that > could work like reverse dollar-quoting. Also Ick. > > As far as we know this has only inconvenienced one person (me) badly > enough to report a maybe-bug. Thanks for trying Bruce, but I fear > this is one itch that'll go unscratched. > > Rest assured I'm not about to storm off and replace all my > installations with MySQL :-)
Good analysis. Basically we can't hope to fully understand COPY or shell quoting syntax well enough to properly replace only unquoted psql variable references. Therefore, unless I hear otherwise, I will just document the limitation and withdraw the patch. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers