#!/usr/local/perl5/bin/perl
use strict;
use warnings;
use JSON::XS;
use File::Slurp qw( read_file );

open(my $fh, '<', '/tmp/test') or die $!; # contains list of file names

my @fields;
my $uuts = {};
while(<$fh>) {
    chomp;
    next if !-e "/tmp/files/$_.json";
    my $decoded = decode_json( read_file("/tmp/files/$_.json") );
    push @fields, $decoded;
}
$uuts->{People} = [ @fields ];
my $coder = JSON::XS->new->ascii->pretty->allow_nonref;
my $pretty_printed_unencoded = $coder->encode ($uuts);
print $pretty_printed_unencoded;