On Fri, Dec 2, 2016 at 6:13 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Fabien COELHO <coe...@cri.ensmp.fr> writes: > >> In psql, if backslash followed by [CR]LF is interpreted as a > >> continuation symbol, commands like these seem problematic > >> on Windows since backslash is the directory separator: > >> > >> \cd \ > >> \cd c:\somepath\ > >> > >> Shell invocations also come to mind: > >> \! dir \ > > > Thanks for pointing out these particular cases. I was afraid of such > > potential issues, hence my questions... > > Those look like nasty counterexamples, but I think they are not, because > they don't work today. What you get is > > regression=# \cd \ > Invalid command \. Try \? for help. > > AFAICT you would need to write it > > regression=# \cd '\\' > \cd: could not change directory to "\": No such file or directory > > (That's on Unix of course, on Windows I'd expect it to succeed.) > > The reason for this is that psql already has a policy that an unquoted > backslash begins a new backslash command on the same line. Since > there is no command named backslash-return, this is available syntax > that can be repurposed in the direction we want. > > I believe that we need to do basically the same thing in pgbench, and > I'm fine with that because I think we should have an overall policy of > synchronizing the psql and pgbench metacommand syntaxes as best we can. > This will at some point necessitate invention of a quoting rule for > pgbench metacommand arguments, so that you can write a backslash as part > of an argument when you need to. We might not need to do that today > (as I'm not sure there are any use-cases for one), but maybe it'd be best > to just bite the bullet and put it in. > > The review from the committer is arrived at the end of commitfest, so moved the patch into next CF with "waiting on author" status.
Regards, Hari Babu Fujitsu Australia
