I have to take exception with previous statements about a lack of central package tracking in debian-based distros. This is completely false. The /var/lib/dpkg directory is used exactly for that purpose. This way all of the apt-based (which as previously pointed out is all dpkg-based anyway) can query any installed package and do stuff with it.
To prove it to yourself strace some dpkg or apt commands. strace -o /tmp/dpkg.out dpkg -l >/dev/null && less /tmp/dpkg.out strace -o /tmp/dpkg.out dpkg --get-selections >/dev/null && less /tmp/dpkg.out strace -o /tmp/dpkg.out apt-cache search chrome >/dev/null && less /tmp/dpkg.out You'll notice that with any of these commands that they open() and read() /var/lib/dpkg/status among others files. Cheers, bd On Sat, Feb 25, 2012 at 12:32 PM, Mike Connors <[email protected]> wrote: > > > > Explain why I should not expect apt to know about all packages > > installed on the computer. You see, in my silly way I assumed that > > whenever a package was installed, regardless of what package manager > > installed it, it would then be listed in a central database file of > > installed apps. Thus, all package managers would know about it. The > > whole operating system would know about it. Menu editors would know > > about it. Even (gasp!) the user of the computer would be able to find > > out about it. There would be no confusion and fragmentation of function. > > > > > Because the package manager is only going to know about the software you > installed with it as there's a difference when software > is installed from source (not a .deb or .rpm *package*) in which the user > may be required to sort out dependencies and conflicts verses > letting the package manager logic sort it out. > > The level and complexity of the logic, the richness of features and keeping > the integrity of installed software intact are the reasons > package managers exist. Before then everything was installed / removed by > hand. How fun it must have been to be a Sys Admin then. > > There is however a way to create a virtual package when installing from > source which would create a place holder in the package system inventory > which would allow you to search the package system for source installed > software and to also keep track of all the dependencies. > > http://www.debian.org/doc/manuals/apt-howto/ch-helpers.en.html#s-equivs > _______________________________________________ > PLUG mailing list > [email protected] > http://lists.pdxlinux.org/mailman/listinfo/plug > _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
