On branch master
 Changes to be committed:
   (use "git reset HEAD <file>..." to unstage)

	deleted:    a.out
	new file:   list_dir_tree.c
	deleted:    null.c

 Changes not staged for commit:
   (use "git add/rm <file>..." to update what will be committed)
   (use "git checkout -- <file>..." to discard changes in working directory)

	deleted:    list.c