#!/usr/bin/perl -wl

    use strict;

    my $s = "FOO=1 BAR= RED BOO = 5.6 BAZ =3";

    my %h;
    $h{lc $1} = $2 while $s =~ s/(\S+)\s*=\s*(\S+)//;

    print $_, "\t=> ", $h{$_} for keys  %h;

    __END__
    Prints:

    foo     => 1
    baz     => 3
    bar     => RED
    boo     => 5.6

##</code><code>##

    #!/usr/bin/perl -wl

    use strict;

    my $s =  "FOO=1 BAR= RED BOO = 5.6 BAZ =3";

    my @a = split /[\s=]+/, $s;
    my %h = map {$_%2 ? $a[$_] : lc $a[$_]} 0..$#a;

    print $_, "\t=> ", $h{$_} for keys  %h;