-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On 06/03/2014 07:19 AM, Horatio Leragon wrote:
[that on 2014-06-03 at 5:08, Andrei POPESCU wrote:] >> Maybe you didn't mean it this way, but dpkg does indeed do >> dependency checking. When provided with a bunch of .deb files to >> install it will take care of proper ordering when needed (Depends:, >> Pre-Depends:, etc.) and will refuse to install packages without >> satisfied dependencies unless > --force switches are used. > > What happens if we choose to use --force switches to install software > with unsatisfied dependencies? That depends on a number of other factors. Literally speaking, dpkg will simply unpack the package's files into their appropriate places and (attempt to) run the preinst, postinst, and any other relevant processing scripts, just as it does on any install. If the preinst, postinst, or other processing scripts rely on the availability of something which (due to unsatisfied dependencies) is not installed, then the install process will be aborted at that point, but AFAIK everything that was done prior to that will remain. If one of the files installed by the package is already on the system, whether because it was also installed by a different package or because you created it by hand or for some other reason, that file will be replaced during the install process. If the original file was required by some other software, then that other software may stop working after the "--force" install. Once the "--force" install is complete, if you try to run the installed program, it may fail to run - for example, if it relies on a library which did not get installed. So in general, installing packages with '--force' is risky; it *can* work just fine if your system happens to be in the right configuration and if you're lucky, but in many cases it will result in something breaking. There's more, and there are some scenarios where it can actually be a good idea; in fact, I suspect apt-get uses 'dpkg --force' itself in some cases, to resolve complex dependency situations during package upgrades. (If you look at the output of 'apt-get dist-upgrade' or 'apt-get install [packagename]', you may occasionally see a line saying something like "Dependency problems, but removing anyway as you request"; if I'm not mistaken, this is the result of apt-get using 'dpkg --force' on an uninstall request.) But for the most part, using 'dpkg --force' is a bad idea unless you know *EXACTLY* wnat you're doing. >> The apt tools are useless without dpkg, however, dpkg will happily >> install .deb files downloaded by any other means. > > What are these "any other means"? Literally any other means of getting a .deb file onto your computer. Downloading it via "save as" in a Web browser, downloading it using a command-line download program such as wget, copying it from another computer onto a Flash drive and then copying it from the Flash drive onto your computer, et cetera. - -- The Wanderer Secrecy is the beginning of tyranny. A government exists to serve its citizens, not to control them. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBCgAGBQJTjb2YAAoJEASpNY00KDJrYhUQAKKLXK1G1RhnZeMxsgMkGxti 1Y505K6eFFlHCWJsrejm2mLibnNgDUxG6JMPWrRZotFkxR2kN4tETAqIWVBJsjEM P6eclaUInt/jT6gYdanwtImwtQOmC0TZnBZXEuXrsLcZrjNv8L8x9Gcd/eECcwkg Rf7WjYHeuqNor1GEyboELusqLvi7O/Ss1MNmD1/PFebVW0yhHoeQuQIHdzmvyO63 FhKtHErF8Vgs2FctkOStdgHIiYOf+Ok/ZvDqGaqDuE8J9JZZx93WoREl3AouFrDr +OZ/Gp67YnzqQjBmOfDIXkFQlMvJ6Zn2/T+4SQ3/5THVKx87CP4aooa0BcqjZ5UZ /CjfH2PJZU014ywDZgQ7ksZf3dTtsQH0/er2+U2KfGv/B8w3KI796CoHAkwwrO1w m42dY3odz1G/ugtjknaafdASQaz2t7wPzwXMz+vL32DYi625Yb75aAHVxOZgsQOz ItaPLsJ4DrpWhUNtu5jhHeuDoFngG1U2jKTSr4M8DWEwSiHFxeSGBAqTy2WD1uCH 5kb5UaktpTs6daVs4gzLBDneSkJl7On2xcM90xxX1lI/044clwqyr2ZUpRp+Zynl xuyivHReZZUJSZxffhaBtbm/x5/vcCu/c42nY/JHWsQoY58uXf5JT92cizeIoHqy 2CyLeyemDeGHBB9hkRZF =vWG4 -----END PGP SIGNATURE----- -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/538dbd98.5070...@fastmail.fm