The current exim_install script renames old versions as xxxx.O. This is
probably reasonable for the various utilities, but it is less than ideal
for the Exim binary itself. For a start, it leaves a window with no exim
when upgrading. For Exim 4 I am proposing to change things. Anybody have
any views on this (relatively minor) change of action?
1. Instead of copying the binary as "exim", copy it into the bin
directory as "exim-4.xx#n". (The #n is the compile number.) If there is
an existing exim-4.xx#n it will be overwritten unless is it newer than
the new file.
2. If there is no "exim" in the bin directory, create a symbolic link
from "exim" to the new binary.
3. If "exim" _is_ in the bin directory, and is a symbolic link, move it
to point to the new binary. This can be done atomically, by
ln -s temp exim-4.xx
mv -f temp exim
4. If "exim" is in the bin directory and is not a symbolic link, run it
to find its version number, and rename it as "exim-x.xx#n". Then create a
symbolic link to the new version.
The normal actions when upgrading will be 1, 3.
A consequence of this is that old versions will accumulate in the bin
directory and will need manually removing from time to time. I don't see
this as a huge problem.
For binaries other than "exim" itself, I am proposing no change.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
