Something

#!/bin/bash

keyword=$1

if [[ $1 = "" ]]
then echo "Please input the keyword to be mass unmerged:"
     read keyword
else :
fi

if [[ $keyword = "" ]]; then
        echo "You need to enter a keyword next time"
        exit
fi

ls -R /var/db/pkg/ | grep $keyword | sed 's/\/var\/db\/pkg\///g' | sed 's/://g' | sed 's/-r[0-9]$//g' | sed 's/\.//g' | sed 's/-[0-9]*$//g' | grep \/ | xargs emerge -pC


echo "These are the packages that I will unmerge. Are you sure you want
to go through with this? [y/n]:"

read var

if [ $var = "y" ]; then
        ls -R /var/db/pkg/ | grep $keyword | sed 's/\/var\/db\/pkg\///g' | sed 's/://g' | sed 's/-r[0-9]$//g' | sed 's/\.//g' | sed 's/-[0-9]*$//g' | grep \/ | xargs emerge -C
else
        echo "Sorry to hear that, maybe you should revise your keyword"
        exit
fi