====== chmod ======

  * chmod [Options]... Mode [,Mode]... file...
  * chmod -R 755 *.txt <-------------- recursive example


  * read 4
  * write 2
  * execute 1

  * **# 	Permission 	        rwx 	Binary**
  * 7 	read, write and execute rwx 	111
  * 6 	read and write 	        rw- 	110
  * 5 	read and execute 	r-x 	101
  * 4 	read only 	        r-- 	100
  * 3 	write and execute 	-wx 	011
  * 2 	write only 	        -w- 	010
  * 1 	execute only 	        --x 	001
  * 0 	none 	                --- 	000