chdir("/")||die "Error:$!\n";
opendir(ROOT_DIR,"/")|| die "Error:$!\n";
foreach $dir_cont (sort readdir(ROOT_DIR)){
  next if $dir_cont =~s/^\.\.?$/;
  if (-f $dir_cont){
    log_sbit($dir_cont) if (-u $dir_cont || -g $dir_cont);
  }
  elsif (-d $dir_cont && opendir(SUB_DIR,"$dir_cont"){
    do_stuff.......
  }

##</code><code>##

/usr/local/bin/some_file  suid
/var/log/.hidden/file  sgid
/home/greco/bin/be_greco  sgid