#!/usr/bin/perl -w
###############################################################
use strict;
use Data::Dumper;

my $data=qq(key1=value1 key2=value2 key3=value3 key4=value4);
my $v={};

foreach my $pair (split(' ',$data)) {
  my($key,$value)=split('=',$pair);
  $v->{$key}=$value;
}

print Dumper($v);