Script which is perform deletion of docker images

docker-image-deletion.sh

#!/bin/bash                                        
if [ "$#" -eq "0" ]; then                          
        echo "Need to specify docker image name"   
        echo "In case if you want to see how much images do you have, just specify image name"        
        echo "Also need to specify count of lines(i.e. count of images) which will be saved"
        echo "Should be something like this: docker-image-deletion.sh 'jenkins' 2"                    
        exit 1                                     
fi                                                 

NUM="^[0-9]+&"                                     

COUNT=$(docker images | grep "^$1 " | wc -l)       

if [ "$#" -eq "2" ] || [[ "$2" =~ "$NUM" ]]; then  

        if [ "$2" -ge "$COUNT" ]; then             
                echo "Wrong number to save images. Count images to save should be less than exist"                                                                                                    
                exit 1                             
        fi                                         

        DELETE_IMAGES=`expr $COUNT - $2`           

        echo "Images which will be deleted"        
        echo "=============================================================="                         
        docker images | grep "^$1 " | tail -n $DELETE_IMAGES                                          
        echo -e "\n\nImages which will be saved"   
        echo "=============================================================="                         
        docker images | grep "^$1 " | head -n $2   
        read -p"Do you want to procced?[y/n]" ANSWER </dev/tty                                        

        if [ "${ANSWER}" == "n" ] || [ "${ANSWER}" == "" ];then                                       
                exit 1                             
        fi                                         

        docker images | grep "^$1 " | tail -n $DELETE_IMAGES | awk '{print $3}' | xargs -d'\n' docker image rm                                                                                               

else                                               

        echo "Images which are available:"         
        echo "=============================================================="                         
        docker images | grep "^$1 "                
fi