NatGeo - Download a month's photos

NG_download_month.sh

#!/bin/sh
CYAN='\033[0;36m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color
currentPath=`pwd`
currentYear=`date +"%Y"`
currentMonth=`date +"%m"`
downloadYear=$1
downloadMonth=$2
force=$3
if [ $# -lt 2 ]
then
 echo "YEAR and MONTH arguments required; eg: ./NG_download_month.sh 2017 06"
 exit
fi
jsonFilename="gallery."$downloadYear"-"$downloadMonth".json"

if [ $currentYear -eq $downloadYear -a $currentMonth -eq $downloadMonth ]
then
 echo "${CYAN}Current month${NC} images get update. Deleting file: $jsonFilename"
 rm $jsonFilename
elif [ $force == '-f' ]
then
 echo "Force deleting file: $jsonFilename"
 rm $jsonFilename
fi

if [ ! -f $jsonFilename ]
then
 echo "${YELLOW}$jsonFilename${NC} unavailable. Downloading..."
 # BASE_URL="http://www.nationalgeographic.com/photography/photo-of-the-day/_jcr_content"
 BASE_URL="https://www.nationalgeographic.com/content/photography/en_US/photo-of-the-day/_jcr_content"
 curl -# ${BASE_URL}/.${jsonFilename} -o $jsonFilename
fi

itemsCount=`cat $jsonFilename | python -c "import sys,json;g=json.load(sys.stdin);print len(g['items'])"`
echo 'Number of images to download: '$itemsCount

for (( i=0; i<$itemsCount; i++ ))
do
 photoOfTheDay=`cat $jsonFilename | python -c "import sys,json;g=json.load(sys.stdin);print g['items']["$i"]['url'] + g['items']["$i"]['originalUrl']"`
 imageFilename=`cat $jsonFilename | python -c "import sys,json,re;g=json.load(sys.stdin);p=g['items']["$i"]['pageUrl'];print re.search('([^\/]+$)', p).group(0)"`
 imageFilename=$downloadYear"-"$downloadMonth"-"$imageFilename'.jpg'
 if [ -f NG_archive/$imageFilename ]
 then
  printf "${YELLOW}Image already exist.${NC} skipping ${CYAN}$imageFilename${NC}\n"
 else
  printf "${YELLOW}Image doesnot exist.${NC} Downloading ${CYAN}$imageFilename${NC}\n"
  curl -# $photoOfTheDay -o NG_archive/$imageFilename
 fi
done