parfile = fopen( uniq_param_name, "w" );
  fprintf( parfile, %s %s %s %s %s %s\n", ip, user, pw, 
           remotepath, remotefilename, localfilename );
  fclose( parfile );
  ...
  sprintf(line, "perl ftp_script.perl %s", uniq_param_name);

  do {
     r = system( line );
     ...
  } ...

##</code><code>##

my $parfile = shift;
open( PAR, $parfile );
$_ = <>;
my ( $ip, $user, $passwd, $remotepath, $remotefilename, $localfilename ) = split;
close PAR;
unlink $parfile;  # why wait for the C code to do this?
...