sub textsformat {

# variables:  initialization
...
...
...
my $text =$_[0];

open (MYFILE, "<$text") || 
     die "the file $text is not readable: $!" ;
open (OUTPUT, ">$text.txt")  ||
     die "can not open $text\.txt with the permission write: $!";

LINE: while(<MYFILE>) {
.....
# Algo for formatting a textfile


      };   
close(MYFILE);
close(OUTPUT);
};


sub dir_explorer
{
  my $entry = $_ ;
  if (-d $entry) { 
     ...  # ignore . and .. 
     opendir(DIR, $entry) or die "Can not open $entry: $!";
     open(FILE, ">>$entry.tab") or die "Can not open $entry with the permission write: $!";
     while( defined (my $file = readdir DIR) ) {
         if (-f "$entry/$file") {
           textsformat("$entry/$file"); #  ....
         };
     };
     close(FILE);
     closedir(DIR);
  };
};

find(\&dir_explorer, "/home/dub/S/programming/perl/dp");