Re: Checking integrity of cached debs

[Winston Smith <viloinuxist@yahoo.co.uk>]

Winston Smith wrote: 
> Is there an easy way to check the integrity of cached debs and remove
> corrupt ones? Also, is there an easy way to check the integrity of the
> unchanging parts of installed packages?

Jhair Tocancipa Triana wrote:
> You can install debsums for that,
> 
>     Description: Verify installed package files against MD5 checksums.
>     debsums can verify the integrity of installed package files against
>     MD5 checksums installed by the package, or generated from a .deb
>     archive.

Thank you, Jhair. That takes care of the second question beautifully.

As for checking the integrity of a possibly un-installed cached deb like
/var/cache/apt/archives/akode_4%3a3.3.2-1_i386.deb,
this is the best I know so far:
Drop the 4%3a ("%3a" is url-ese for ":") from the base to obtain
akode_3.3.2-1_i386.deb, which you look for in the "Filename:" field of
the entries in the "Packages" files in /var/lib/apt/lists (or downloaded
packages.gz files from the mirrors in /etc/apt/sources.list). Take the
md5sum from the entry where you find it, and compare it to the actual
md5sum of the cached deb.

Win