use warnings;
use strict;

use Data::Dumper;

my %app_map;

open my $fh1, '<', 'app.txt' or die $!;

while (my $line = <$fh1>){
    my ($app, $mem, $lang) = split /\s+/, $line;
    $app_map{$app}{mem} = $mem;
    $app_map{$app}{lang} = $lang;
}

close $fh1 or die $!;

open my $fh2, '<', 'app2.txt' or die $!;

while (my $line = <$fh2>){
    my ($app, $cpu, $cores) = split /\s+/, $line;
    $app_map{$app}{cpu} = $cpu;
    $app_map{$app}{cores} = $cores;
}

close $fh2 or die $!;

print Dumper \%app_map;

##</code><code>##

App1 	4 	Perl
App2 	8 	Java
App3 	8 	Java
App4 	4 	PHP
App5 	8 	C#

##</code><code>##

App1 	1.5 	2
App2 	2.5 	4
App3 	2.8 	4
App4 	2.8 	2
App5 	2.8 	2

##</code><code>##

$VAR1 = {
          'App5' => {
                      'lang' => 'C#',
                      'cores' => '2',
                      'cpu' => '2.8',
                      'mem' => '8'
                    },
          'App1' => {
                      'cores' => '2',
                      'cpu' => '1.5',
                      'mem' => '4',
                      'lang' => 'Perl'
                    },
          'App4' => {
                      'cpu' => '2.8',
                      'cores' => '2',
                      'mem' => '4',
                      'lang' => 'PHP'
                    },
          'App3' => {
                      'cpu' => '2.8',
                      'cores' => '4',
                      'mem' => '8',
                      'lang' => 'Java'
                    },
          'App2' => {
                      'mem' => '8',
                      'cores' => '4',
                      'cpu' => '2.5',
                      'lang' => 'Java'
                    }
        };