perl - How to traverse all the files in a directory and subdirectories as well -

i working on script read file , based on file content have rename file.

problem facing :

1st not able read file in subdirectory. 2nd trying rename file error occuring.

here code:

               folder structur :                         logs                       / / / \                       b c  d                    / \ \                   e file file 

where a,b,c,d,e dir file,file txt file

#!/usr/bin/perl  use strict; use warnings; use file::copy::recursive; use cwd; $file; (@files,@file_01); ($dir_01,$dir_02); $new_file="kernel.txt"; chdir('c:\\abd\\efg'); $dir_01 = getcwd; opendir(dir_01, $dir_01); @files=readdir(dir_01); close(dir_01); foreach $dir_02 (@files) {   opendir (dir_02, "$dir_01"."/"."$dir_02") ;    @file_01=readdir(dir_02);    close(dir_02);     foreach  $file (@file_01)     {       open(fh,"<","$dir_01/$dir_02/$file") or die "can not open file $!\n";         while(my $lines = <fh>)         {           if($lines=~ m/linux kernel version/i || $lines=~ m/usb_state=disconnected/gi)            {             #print "\t$lines\n\n";             rename($file,$new_file) or die "can not change name";             }         }     } }    

rename($file,$new_file)  

will not work did not specify path

rename("$dir_01/$dir_02/$file", $new_file) 

but file matches renamed kernel.txt in current directory. expected behavior?