How to parse this JSON object/string? - json

Question

I am trying to parse the JSON written # http://a0.awsstatic.com/pricing/1/ec2/sles-od.min.js
Here is a quick snippet from above link:
{vers:0.01,config:{rate:"perhr",valueColumns:["vCPU","ECU","memoryGiB","storageGB","sles"],currencies:["USD"],regions:[{region:"us-east",instanceTypes:[{type:"generalCurrentGen",sizes:[{size:"t2.micro",vCPU:"1",ECU:"variable",
...
...
...
...
Please visit the aforementioned link to see the complete JSON.
As seen above, none of the keys of above JSON have Double Quotes around them.
This leads to malformed JSON string and my JSON parser is failing at it. I also tried putting this JSON in http://www.jsoneditoronline.org/ and it fails as well.
Now, this is the same link which is used by Amazon to display various prices of their EC2 instance. So I think I am missing something here. My Googling led me to believe that above thing is not JSON and is instead JSONP.. I don't understand what is that.
Could you help me understand how to parse this JSON. BTW, I am doing this work in perl using JSON Module.
Some background:
Amazon Web Services does not have an API to get Pricing info programmatically. Hence I am parsing these links which is what amazon is doing while displaying pricing information here. Besides, I am not from programming space and perl is all I know.

Answer 1

Like you said JSONP or "JSON with padding" can't be parsed by json parser because it is not json (it is a different format). But it is actually a json with the prefix (padding)
The padding is typically the name of a callback function that wraps json.
In this case, its default callback names 'callback' and we can do a bit hackiest way by using Regular Expression to capture json that is wrapped by 'callback()' like this
s/callback\((.*)\);$/$1/s;
Also, if you would like to use JSON library, you can enable allow_barekey which means you don't need those quotes around those keys.
Below is my working code. I use LWP::Simple to get the content for the given and Data::Dump to print the isolated data structure.
use strict;
use warnings;
use LWP::Simple;
use JSON;
my $jsonp = get("http://a0.awsstatic.com/pricing/1/ec2/sles-od.min.js")
or die "Couldn't get url";
( my $json = $jsonp ) =~ s/callback\((.*)\);$/$1/s; #grap the json from $jsonp and store in $json variable
my $hash = JSON->new->allow_barekey->decode ( $json );
use Data::Dump;
dd $hash;
Outputs:
{
config => {
currencies => ["USD"],
rate => "perhr",
regions => [
{
instanceTypes => [
{
sizes => [
{
ECU => "variable",
memoryGiB => 1,
size => "t2.micro",
storageGB => "ebsonly",
valueColumns => [{ name => "os", prices => { USD => 0.023 } }],
vCPU => 1,
},
{
ECU => "variable",
memoryGiB => 2,
size => "t2.small",
storageGB => "ebsonly",
valueColumns => [{ name => "os", prices => { USD => 0.056 } }],
vCPU => 1,
},
{
ECU => "variable",
memoryGiB => 4,
size => "t2.medium",
storageGB => "ebsonly",
valueColumns => [{ name => "os", prices => { USD => 0.152 } }],
vCPU => 2,
},
{
ECU => 3,
memoryGiB => 3.75,
size => "m3.medium",
storageGB => "1 x 4 SSD",
valueColumns => [{ name => "os", prices => { USD => "0.170" } }],
vCPU => 1,
},
....

Answer 2

As said in comments above, it is not JSON so it can't be parsed by JSON parser... But for an quick & (very)dirty work, you can try the JSON::DWIW module.
The next code:
use 5.014;
use warnings;
use WWW::Mechanize;
use Data::Dump;
use JSON::DWIW;
my $mech = WWW::Mechanize->new();
my $jsonstr = $mech->get('http://a0.awsstatic.com/pricing/1/ec2/sles-od.min.js')->content;
($jsonstr) = $jsonstr =~ /callback\((.*)\)/s;
my $json_obj = JSON::DWIW->new;
my $data = $json_obj->from_json( $jsonstr );
dd $data;
prints a structure what maybe is what you want, e.g.:
{
config => {
currencies => ["USD"],
rate => "perhr",
regions => [
{
instanceTypes => [
{
sizes => [
{
ECU => "variable",
memoryGiB => 1,
size => "t2.micro",
storageGB => "ebsonly",
valueColumns => [{ name => "os", prices => { USD => 0.023 } }],
vCPU => 1,
},
{