In response to your short example using Mojo::UserAgent: (which I couldn't figure out how to respond to directly):

I modified your code as follows to read url's from a file:

use strict;
use warnings;
use Mojo::UserAgent;

my $filename = 'urls_Mojo.txt';
open(my $fh, '<:encoding(UTF-8)', $filename)
  or die "Could not open file '$filename' $!";
my $y = 0;              # input row count
while (my $row = <$fh>) {
  $y++;
  print $y;
  print " $row";

my $url = $row;

# create a Mojo:UserAgent

my $ua = Mojo::UserAgent->new;

# use $ua to get the url and assign the value of 'subscriber_count' in
+ the json
# to avariable, $subscribers

my $subscribers = $ua->get( $url )->result->json->{subscribers_count};

# print the variable to screen

print "Number of subscribers: $subscribers\n";
}
[download]

it worked when the file 'urls_Mojo.txt' contained

https://public-api.wordpress.com/rest/v1/read/feed/http%3A%2F%2Fthe-ar
+t-of-autism.com%2Ffeed
[download]

but gave a "Can't use an undefined value as a HASH reference" error when I added a second line to 'urls_Mojo.txt' as follows:

https://public-api.wordpress.com/rest/v1/read/feed/http%3A%2F%2Fthe-ar
+t-of-autism.com%2Ffeed
https://public-api.wordpress.com/rest/v1/read/feed/http%3A%2F%2Fanauti
+smobserver.wordpress.com%2Ffeed
[download]

Can you help me figure out how to apply this script to a list of url's in a file? Thanks.