[Cupt-devel] Bug#680012: wanted: 'cache-only-upgrade'

[A. Costa]

Package: cupt
Version: 2.5.7
Severity: wishlist

Dear Maintainer,

It would be useful for low bandwidth users to have a 'cache-only-upgrade'
option. 

Apt can already do that using:

    apt-get --no-download  --ignore-missing upgrade

...I'm not sure how to make that work for 'cupt', without running both
'cupt update' and 'apt-get update' regularly. To save bandwidth I'd
rather avoid running 'apt-get update'; also, keeping 'apt-get' in sync
with 'cupt' can be difficult.

Application:  suppose a 400M (modem) upgrade needs 24 hours at 5K/sec, but
bandwidth is only available late at night, say 8 hours.  In the
morning, some packages can usually be upgraded, (since their
dependencies have all been fetched), but which packages?  Then at the
end of 3 days, there's new updates, and catching up can be delayed
endlessly.

In the meantime, for users who don't mind a (quite slow) kludge, this 
seems to work:

   # get 'cupt' to just upgrade only what's in the cache.
   # parse upgradeable cached .deb files for '0B', make
   # a list, and install with 'cupt'.
   cupt -y iii `cupt -d -y  safe-upgrade 2> /dev/null | \
   grep -A 2 "The following packages will be upgraded" | \
   tail -n 1 | tr ' ' '\n' | \
   while read p ; do \
       yes q | cupt iii $p 2> /dev/null | \
       grep -q "get 0B" && echo -n $p" " ; \
   done`

HTH...
    

-- System Information:
Debian Release: wheezy/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 3.2.0-3-686-pae (SMP w/2 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968) (ignored: LC_ALL set to C)
Shell: /bin/sh linked to /bin/dash

Versions of packages cupt depends on:
ii  libboost-program-options1.49.0  1.49.0-3.1
ii  libc6                           2.13-34
ii  libcupt2-0                      2.5.7
ii  libgcc1                         1:4.7.1-2
ii  libstdc++6                      4.7.1-2

cupt recommends no packages.

Versions of packages cupt suggests:
ii  libreadline6    6.2-8
ii  sensible-utils  0.0.7

-- no debconf information