use LWP::UserAgent;
use HTTP::Request;
my $user = "JIRAusername";
my $password = "Lamepassword";
my $jira_url = "put_your_server_here";
my $ck=LWP::UserAgent->new( );
my $getline= $jira_url . '/jiraurl/rest/auth/1/session'; 
my $request = new HTTP::Request (GET => $getline, HTTP::Headers->new('Content_Type' => 'application/json') );
$request->authorization_basic($user, $password);
my $answer = $ck->request ($request);
my $cookie = $answer->header('Set-Cookie');


##</code><code>##

my $ua=LWP::UserAgent->new( keep_alive => 1 );
my $key = 'existing_issue_code'; #this is just for test. You can use any issue you get from web JIRA
$getline=$url . '/rest/api/latest/issue/' . $key;
$request = new HTTP::Request (GET => $getline, HTTP::Headers->new('Cookie'=> $cookie ) );
$answer = $ua->request ($request);