On Mon, Jan 30, 2017 at 06:38:16PM +0000, Robie Basak wrote: > > So how about this, just a sketch at the moment rather than a full > > patch? > > Your sketch seems good to me, assuming that "dpkg-query --search" is > permitted from maintainer scripts (I know there are some re-entrancy > problems with some particular types of dpkg-related invocations?)
AFAIK it is safe to run dpkg-query, as it only queries the dpkg database without performing any actions: it can be run as an unprivileged user, for example. (It is equivalent to "dpkg -S", btw.) It is already used in numerous maintainer scripts, as a quick "grep dpkg-query /var/lib/dpkg/info/*.p* shows. With a little more checking, it turns out that the dpkg-query command can be simplified, as it doesn't do a pattern search without an explcit request, so the following should also work: daemonpackage=$(dpkg-query -S /usr/sbin/mysqld 2>/dev/null | cut -d: -f1) The "|| true" is probably also unnecessary, as the pipeline will succeed unless the "cut" command fails, which is highly unlikely. > [...] > > I wondered this too. But without thinking it through in more detail, > it'd certainly be better than what we have now. Fair enough. If implementing it, it should probably be done together with the patches I sent to the other bug report, and applied to both the mysql-server and mariadb-server packages. Best wishes, Julian