Cisco Routers for the Desperate, 2nd Edition

Command Abbreviation

One interesting feature of the Cisco IOS is that it allows the user to abbreviate command names to the shortest unique abbreviation for a word. For example, one common command we'll use again and again to view settings is show. If you ask your router for all the commands beginning with the letter s, you'll get a whole list.

 router# s?
 *s=show  sdlc  send        set     setup
 show     slip  start-chat  systat
 router#

Note that only the command show begins with the letters sh . You can use the letters sh as an abbreviation for the full word show ...