#!/usr/bin/perl
use strict;
use warnings;
use LWP::UserAgent;
use JSON;

my $client = new LWP::UserAgent;
my $json = new JSON;

my %request=('commandlet'=>'memory','output'=>'json');
my $json_request = $json->encode(\%request);

my $web_request = $client->post('http://localhost:12345/query',{ username => 'default',
								password => 'changeme',
								json => $json_request
								});
print $web_request->content; 

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
use JSON;
my $json = new JSON;
my %request=('commandlet'=>'memory','output'=>'json');

my $json_data=$json->encode(\%request);
my $command=sprintf"/usr/bin/curl -d username='%s' -d password='%s' --data-urlencode json='%s' http://localhost:12345/query 2>/dev/null|","default","changeme",$json_data; 

open FH,$command;
while (<FH>){
	print $_;
	}
close FH;

##</code><code>##

Using curl:

real	0m4.006s
user	0m3.060s
sys	0m0.740s

Using LWP

real	0m12.978s
user	0m11.405s
sys	0m1.184s