[Mimedefang] Does MIMEdefang 'remember' variable values between successive invocations?

[Rolf E. Sonneveld]

Hi,

running 2.71

Within filter_begin the mimedefang-filter script reads in variables from 
a config file (mimedefang-filter.conf), to separate data from script and 
to make changing variables a dynamic process:

# Read variables from configuration file...

    my $success = open CONFIG, "<", "$bindir/mimedefang-filter.conf";
    if ( $success ) {
       while (<CONFIG>) {
          chomp;
          s/#.*//;
          s/^\s+//;
          s/\s+$//;
          next unless length;
          ($var, $value) = split(/\s*=\s*/, $_, 2);
          no strict "refs";
          $$var = $value;
       }
       close CONFIG;

Now, it seems to me it's not as dynamic as I thought it was. I have 
tested manually a number of messages (runs):

Run 1: I define variable $var in mimedefang-filter.conf to be "xyz". 
Works OK.
Run 2: I redefine variable $var to be "abc". Works OK.
Run 3: I removed variable $var from the config file and check in the 
script whether the variable is undefined or not. The variable is not 
undefined: it still contains value "abc"!

Then I run /etc/init.d/mimedefang reread

Run 4: $var is still not defined in mimedefang-filter.conf. This works 
OK, the variable $var is now undefined within the context of the script.

Now I wonder: does MIMEdefang keep state between successive runs? Is 
there a way I can 'clean up' (= undefine) all variables before a run? 
The workaround I now use is, that the variables in the config file are 
defined without a value and then in the script I set the variable to an 
empty string and check the variable for an empty value:

# Read variables from configuration file...

    my $success = open CONFIG, "<", "$bindir/mimedefang-filter.conf";
    if ( $success ) {
       while (<CONFIG>) {
          chomp;
          s/#.*//;
          s/^\s+//;
          s/\s+$//;
          next unless length;
          ($var, $value) = split(/\s*=\s*/, $_, 2);
          no strict "refs";
          $$var = "";
          $$var = $value;
       }
       close CONFIG;

I would prefer to be able to remove or comment out a variable in the 
config file and not having to do a 'reread' of mimedefang.
Any ideas?

/rolf