add album cover art to flac audio files

add_cover_flac.sh

#!/bin/bash
# add cover art image to flac audio files, requires metaflac
# run from working directory

SECONDS=0
COVER=${1}
COUNT=$(ls *.flac | wc -l)
COUNTER='1'
CMD='metaflac'
NC='\e[0m'
WHITE='\e[1;37m'
YELLOW='\e[1;33m'
LIGHT_BLUE='\e[1;34m'
CYAN='\e[0;36m'
RED='\e[0;31m'

displaytime () {
    local T=$SECONDS
    local D=$((T/60/60/24))
    local H=$((T/60/60%24))
    local M=$((T/60%60))
    local S=$((T%60))
    [[ $D > 0 ]] && printf '%d days ' $D
    [[ $H > 0 ]] && printf '%d hours ' $H
    [[ $M > 0 ]] && printf '%d minutes ' $M
    [[ $D > 0 || $H > 0 || $M > 0 ]] && printf 'and '
    printf '%d seconds\n' $S
}

if [ "$1" == "" ]; then
    echo -e "Please enter the path to the cover art. Exiting.\n"
    exit 1
fi

if [[ -e "${COVER}" ]]; then
    echo ""
    echo -e "Cover art file ${WHITE}${COVER}${NC} found. Proceeding...\n"
    else
       echo -e "Cover art file ${WHITE}${COVER}${NC} not found. Exiting.\n"
       exit 2
fi

if ! [ -x "$(command -v ${CMD})" ]; then
    echo -e "${RED}Error: ${CMD} is not installed. Exiting.${NC}\n" >&2
    exit 3
    else
        echo -e "${CMD} found at $(command -v ${CMD}). Proceeding...\n"
fi

if [ "$COUNT" == "0" ]; then
    echo -e "${RED}Error: No .flac files found. Exiting.${NC}\n"
    exit 4
fi

echo -e "Adding ${WHITE}${COVER}${NC} to ${WHITE}${COUNT}${NC} .flac audio files...\n"

for i in *.flac ; do 
	echo -ne "${COUNTER}/${COUNT} - Updating file \"${WHITE}${i}${NC}\" ... "
	${CMD} --import-picture-from="${COVER}" "${i}" 
	echo "Done."
        (( COUNTER++ ))
done 

TIME=$(displaytime)
echo ""
echo -e "Completed in ${YELLOW}${TIME}${NC}.\n"

exit 0