title: copy without overwrite and preserve existing files with extended name
body: <p>i need to copy files with specific extensions. but the problem is there are multiple files with same file name.i dont want to overwrite them and store as copy like file _1,file_2 etc. when i tried using unix command line the files are overwitten though i used cp -n.
  is there any way i can do this task using command line or perl ?
  the command i used was </p>
  
  <blockquote>
    <p>find -L . -name "*.txt" -exec cp -n {} -t ~/destination</p>
  </blockquote>