sub log {
  open (LOG,">>log") || die $!;
  print LOG "$_[0]\n";
  close LOG;
}

##</code><code>##

sub sub-name {
  log("Entering sub-name");
  ...
  log("Leaving sub-name");
}

##</code><code>##

log("querying VAX: $vaxen_query");
execute $vaxen_query;

log("SQL query: $mangled_sql_query");
execute $mangled_sql_query;