compare.sh

#!/bin/bash
file_a=`cat $1`
file_b=`cat $2`
while IFS= read -r line_a
do
    while IFS= read -r line_b
    do
        if [ "$line_a" != "$line_b" ];then
            #echo "$line_a : $line_b"
            echo "$line_b will be deleted"
            echo "----"
            docker rmi -f $line_b
        elif [ "$line_a" == "$line_b" ];then
            #echo "$line_a : $line_b"
            echo "$line_a will be unchanged"
            echo "----"
        fi
    done <<< "$file_b"
done <<< "$file_a"