Re: dpkg/apt voodoo to ask "what version of <pkg> is installed, if any?"

[Dmitriy Matrosov <sgf.dma@gmail.com>]

On 09/12/12 23:44, Kris Deugau wrote:
> I already have this and it's been working well for quite a while:
>
>    dpkg-query --showformat '\${status}\t\${version}\n' -W $pkg
>
> Unfortunately I've just discovered it fails when $pkg is a virtual
> package, and I have no way to tell ahead of time if this is the case or
> not (nor does the caller care).
>
> Is there a single command that can do this for both virtual and real
> packages, a la "rpm -q --whatprovides"?
>
> Some searching turned up references to apt-cache dumpavail, but that
> isn't restricted to the currently installed packages.  The --installed
> option seems to be ignored for dump and dumpavail.
>
> (Please CC me on replies.)
> -kgd
>
>
>    
Hi.

May be something like: (example for mail-transport-agent)

$ apt-cache  showpkg mail-transport-agent \
    | sed -ne'/Reverse Provides/,$p' \
    | sed -ne '2,$s/ .*//p' \
    | xargs -d'\n'  sh -euf -c '
        dpkg-query --showformat 
"\${package}\t\${status}\t\${version}\n" -W "$@" 2>/dev/null \
            | grep -v "not-installed"
        ' sh