Re: PW#5-13: New virtual packages>
Christian Schwarz <schwarz@monet.m.isar.de> writes:
> > However, managing /bin/sh through alternatives sounds like a good
> > idea to me.
Ian wrote:
>Be careful; I'm not sure whether update-alternatives guarantees always
>to have one link present. This needs to be looked at _very_
>carefully. We must not allow the system to pass even momentarily
>though a state where /bin/sh does not exist.
AFAICT, update-alternatives wouldn't change /bin/sh at all, only
/etc/alternatives/sh (or whatever's used), but it -does- seem to be
careful to create a new symlink /etc/alternatives/sh.dpkg-tmp and rename
it to /etc/alternatives/sh after that's succeeded. More critical, I
think, is making sure that calls to update-alternatives only occur at
the correct times in the shells' maintainer scripts.
Incidentally, one way to ensure that there's always a /bin/sh installed,
even when bash isn't essential, would be to have all the editors "Provide:
posix-sh" and have another essential package depend on posix-sh.
Preferably the chosen package would be one that actually uses sh...
sysvinit for example. A lot of base packages could probably be made
non-essential this way...
--
Charles Briscoe-Smith
White pages entry, with PGP key: <URL:http://alethea.ukc.ac.uk/wp?95cpb4>
PGP public keyprint: 74 68 AB 2E 1C 60 22 94 B8 21 2D 01 DE 66 13 E2
Reply to: