Hey Guillem.
On Fri, 2024-02-16 at 05:26 +0100, Guillem Jover wrote:
>
> Thanks!
Well rather: thank you, for your constant efforts to DPKG and the whole
ecosystem.
> > At least it seems to make it impossible to definitely find out
> > whether a package
> > is not installed (respectively not existant).
>
> Exactly.
Maybe it would also be worth to elaborate on:
1 The requested query failed either fully or partially, due to no
file or package being found (except for --control-path,
--control-list and --control-show were such errors are fatal).
My understanding would have been, that e.g. when searching for a
package, 1 would in practise mean that it doesn't exist at all (when
looking from APT’s PoV) respectively is in the state 'not-installed'.
So I guess for end-users it might be helpful to be told that, i.e. that
these two things (non-existing from APT) and non-installed are the same
from DPKG’s PoV, and would trigger 1.
Also perhaps notifying somewhere that 'not-installed' will never really
show up anywhere as a printed query result.
> This is used for field names, be them real or virtual, so erroring
> out
> on fields that do not exist would seem bad. But there's the
> distinction between the real fields and virtual ones, where the
> latter
> always contain a colon. So I guess I could make the latter, at least
> warn if they do not exist. My main concern with making them errors,
> is
> that this would break backwards and/or forwards compatibility, where
> you could not use a new or renamed field with old or new releases.
Warnings are at last difficult to use when scripting.
And btw: it also succeeds if there's no colon, e.g.:
$ dpkg-query --showformat='${foobar}' --show 2>/dev/null ; echo $?
0
Thanks,
Chris.
PS: In the dpkg-query manpage, there's:
Desired action:
u = Unknown
i = Install
h = Hold
r = Remove
p = Purge
Package status:
n = Not-installed
c = Config-files
H = Half-installed
U = Unpacked
F = Half-configured
W = Triggers-awaiting
t = Triggers-pending
i = Installed
Error flags:
<empty> = (none)
R = Reinst-required
I think, when these are actually printed, the full names are all
lowercase, i.e. installed not Installed ... might perhaps make sense to
align that?
