while (<DATA>) {
    chomp;
    my ($var, $value);
    if ( /\s*(\w+)\s*=\s*([^;]+)/ || /\s*(?:set|setenv)\s+(\w+)\s+([^;]+)/ ) {
        ($var, $value) = ($1, $2);
    } else {
        next;
    }
    while ($value =~ /\\$/) {
        my $temp .= <DATA>;
        chomp $temp;
        $temp =~ s/^\s*//;
        $temp =~ s/\s*$//;
        $value =~s/\\$/$temp/;
    }
    if ($value =~ s/^\$(\w+)//) {
        $value .= $env_var{$1} || '';
    }
    $env_var{$var} = $value;
}

foreach my $key (keys %env_var) {
    print "$key = $env_var{$key}\n";
}

__DATA__

NAME1 = VALUE1
set NAME2 = VALUE2
setenv NAME3 = VALUE3
   NAME4=VALUE4 \
         VALUE5