Shodan IPCam extractor

#!/bin/bash
#
# By Arsouill3 @ 8ch.net/ipcam/
#
# Shodan IPCam Extractor allows you to download IP (of IPCam) from Shodan.io thanks to its API. You'll need to suscribe either Developer or Freelancer plan
# (https://developer.shodan.io/billing/signup) to use it.
# cURL (http://curl.haxx.se/download.html) and jq (https://stedolan.github.io/jq/download/) are required.
# The script has been written to get all IP (of IPCam) all over the world on a daily basis. If you want to do so, then edit crontab (crontab -e) as follow :
#       * 20 * * * PATH/shodan_ipcam_extractor.sh $country_iso_2letters $date (script will be launched everyday at 8 p.m.)
#
# ./shodan_ipcam_extractor.sh $country_iso_2letters $date :
#       * $country_iso_2letters : Alpha-2 code of a country (https://www.iso.org/obp/ui/#search) | all
#       * $date : all | y (stands for yesterday)

api_key="" # Paste your Shodan's API key here
country=$1
date=$2
today=$(date +'%s')
shodan_today=$(date --date="@$today" "+%d/%m/%Y")
yesterday=$(($today-24*3600))
bfyesterday=$(($yesterday-24*3600))
shodan_bfyesterday=$(date --date="@$bfyesterday" "+%d/%m/%Y")
query1="netwave ip camera country:$country before:$shodan_today after:$shodan_bfyesterday" # Download all IPCam of $country posted on yesterday
query2="netwave ip camera country:$country" # Download all IPCam of $country
query3="netwave ip camera" # Download all IPCam
query4="netwave ip camera before:$shodan_today after:$shodan_bfyesterday" # Download all IPCam posted yesterday

if [ ! -d "./JSON_files" ]
then
        mkdir "./JSON_files"
fi

function collect_ip { # collect_ip $api_key $query
i=1
nbr_ip=1
while [ "$nbr_ip" -gt "0" ]
do
        code_status=$(curl -L -w "%{http_code}" "https://api.shodan.io/shodan/host/search?key=$1&query=$2&page=$i" -o ./JSON_files/shodan_$i.json)
        if [ "$code_status" -ne "200" ]
        then
                echo "Error ! Maybe a lack of credit ? $(date "+%c")" >> ./error_shodan.log
                nbr_ip=0
                i=$(($i+1))
        else
                nbr_ip=$(jq '.matches | length' < ./JSON_files/shodan_$i.json)
                i=$(($i+1))
        fi
done
i=$(($i-1))
rm "./JSON_files/shodan_$i.json"
}

function extract_ip {
nbr_files=$(ls ./JSON_files/ | wc -l)
if [ "$nbr_files" -gt "0" ]
then
        for (( j=1; $j<=$nbr_files; j++ ))
        do
                nbr_ip=$(jq '.matches | length' < ./JSON_files/shodan_$j.json)
                for (( i=0; $i<=$nbr_ip-1; i++ ))
                do
                        ip=$(jq --raw-output .matches[$i].ip_str < ./JSON_files/shodan_$j.json)
                        printf "%s\n" "$ip" >> ./shodan_ip.txt
                done
        rm "./JSON_files/shodan_$j.json"
        echo "File $j processed."
        done
else
        echo "JSON_files directory is empty !"
        exit
fi

# Split shodan_ip.txt into files of 4000 lines max each
if [ -f "./shodan_ip.txt" ]
then
        nbr_line_ip=$(wc -l ./shodan_ip.txt | sed 's/^\(.*\) \..*/\1/')
        split=$(($nbr_line_ip/4000)) # 4000 is nearly the max quantity of IP to prevent Joe's FileDownloader of crashing...
        for (( i=1; $i<=$split; i++ ))
        do
                j=$((4000*$i-3999))
                k=$((4000*$i))
                sed -n -e $j,$k'p' ./shodan_ip.txt > ./shodan_ip_$i.txt
        done
        sed -n -e $(($k+1)),'$p' ./shodan_ip.txt > ./shodan_ip_$i.txt
else
touch ./shodan_ip.txt
fi
}

# Beigining of "main"
if [ "$country" = "all" ]
then
        if [ "$date" = "all" ]
        then
                collect_ip $api_key $query3
                extract_ip
        else
                collect_ip $api_key $query4
                extract_ip
        fi
else
        if [ "$date" = "y" ]
        then
                collect_ip $api_key $query1
                extract_ip
        else
                collect_ip $api_key $query2
                extract_ip
        fi
fi