Useful+Linux+commands

=Extremely useful commands:=
 * ===General usage:===
 * 1) To find size of file : **stat** -c %s 
 * 2) To find number of lines in file : **wc** -l 
 * 3) To read a long file gradually from top : **more** 
 * 4) To show the whole contents of a file : **cat** 
 * ===Advanced usage:===
 * 1) To find disk parameters : **hdparm** -options 
 * 2) To check how fast disk can be accessed use **-t** for general access and **-T** for cached access.