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

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

map { my($k,$vl) = split('=',$_); 
      $v->{$k}=$vl;
    } split(' ',$data);

print Dumper($v);