I have a simple requirement. I want to define several variables that will correspond to any number of given packages I want to install via a shell script.

Sample code below:

MISC="shutter pidgin"

WEB="apache2 mongodb"



for pkg in $MISC $WEB; do

    if [ "dpkg-query -W $pkg | awk {'print $1'} = """ ]; then

        echo -e "$pkg is already installed"

    else

        apt-get -qq install $pkg

        echo "Successfully installed $pkg"

    fi

done

Everything kinda works, but the logic seems flawed because it's not reliably installing the packages I want. It either says they've been installed already or it's trying to install packages that have already been installed previously.

I've also been trying with command -v or the following:

if [ "dpkg -l | awk {'print $2'} | grep --regexp=^$pkg$ != """ ]; then

And even with the -n and -z flags to check if the returned string was empty. Pretty sure I'm missing some good sense here.

Do you have any idea what I could do to make sure a package is actually installed or not?

Thanks!