Bash loop cURL+ wget API extraction

Script to automate a set of sequential downloads from bounded list of Ids.

Use cURL to get the JSON data from the API and then extract the relevant fields to create a nice CSV download and finally remove the unnecessary quote characters in the output.

Linux commands used

• cURL
• wget
• tr

#!/bin/bash

timestamp() {
	date +%Y-%m-%dT%H:%M:%S%z
}

printLine() {
	printf "$(timestamp): $1\n"
}

while getopts s:u:k:e: option
do
case "${option}"
in
s) start=${OPTARG};;
u) api_url=${OPTARG};;
k) key=${OPTARG};;
e) end=${OPTARG};;
esac
done

if test -z "$start"
then
	printLine "No start id specified"
	exit 1
fi

if test -z "$end"
then
	printLine "No end id specified"
	exit 2
fi

if test -z "$api_url"
then
	printLine "No API url specified"
	api_url="<DEFAULT_API_URL>"
fi
printLine "API url to use $api_url"

if test -z "$key"
then
	printLine "No API key specified"
	exit 4
fi

if (( start > end ));
then
	printLine "$start id > $end id"
	exit 3
fi

while (( start <= end )); do
	name=`curl $api_url?Id=$start\&api_key=$key\&format=json | jq '.queries | .[] | .notes + "_" + (.latitude|tostring) + "," + (.longitude|tostring) + ".csv"' | tr -d '"'`
	echo $name
	get=`wget -O $name $api_url/$start?api_key=$key`
    echo "$get"
	start=$[start+1]
done