Date:        Tue, 7 Mar 2000 17:16:54 +0100
    From:        Thilo Manske <Thilo.Manske@HEH.Uni-Oldenburg.DE>
    Message-ID:  <20000307171654.E25607@WintelKiller.HEH.Uni-Oldenburg.DE>

  | Well, since nearly nothing except vi uses /var/tmp in the proper way
  | (i.e. for stuff that may be of need for longer than a few minutes)

That's never really been the "proper way".   Originally there was just /tmp.
They was often too small, so /usr/tmp was added as an alternative for
things that were too big for /tmp.  (/usr/tmp later transformed to /var/tmp).
After that, /tmp was made into a "clear at boot" system and editor
temp files were moved to /usr/tmp.   And then taking advantage of that,
/tmp became often mounted via MFS (which forces clear at boot).

These days, generally /tmp is for things that are small, prefer fast
access, and truly transient.  If any of those assumptions are
violated, /var/tmp is the better choice.

  | my /tmp has about twice as much space free as my /var/tmp, e.g.

I suspect that is the unusual case.

  | Most programs (tar, pax, compiler stuff, many, many packages - nearly
  | everything except updateddb.csh?) use /tmp as default to store their
  | temporary files

sort doesn't.   sort and updatedb are the two which have a tendancy to
generate huge files (sometimes).

  | ---often larger than the average stuff updatedb.csh creates---

You must have small filesystems - the updatedb files I've seen
can run to hundreds of MB.

  | Nobody should make asumptions about the size of /tmp or /var/tmp,

If there are to be any defaults at all, some kinds of assumptions need
to be made - the ideal is not to just change things to suit the needs of
any odd user - but to look at the common case.

  | i.e. wich of the two has more free space. It's about purpose:
  | Store temporary stuff you will need after the next [re]boot in /var/tmp
  | and everything else in /tmp. (At least this is how I understand hier(7))

hier(7) tells you that /tmp can be cleared at boot, and /var/tmp
won't be - that's important knowledge.  I don't think it was ever
intended to mandate that only files which you want kept beyond
reboots should go in /var/tmp.

  | So (IMHO) updatedb.csh really should use /tmp - if this doesn't work for
  | some user [s]he will have to adjust the size of /tmp or set TMPDIR (e.g. in
  | weekly.conf) to something else - as [s]he has to do with every other program.

I'd say exactly the opposite - put things back the way they were, if
some user needs /tmp to be used because they have a very small /var, then
they get to set TMPDIR ...

kre

ps: is no-one else other than me itrritated that updatedb is written in
csh rather than sh - if there's no objection, I'll convert it.
Previous experience doing this is that non-trivial scripts usually shrink
to about half the size, and become an order of magnitude clearer
when this is done...