how to determine copu usage and io usage for a particular user logged on linux?

[Raghudev Ramaiah]

Hello,
 
How can i collect statistics wrt amount of cpu used , amount of memory used, amouint of  I/O done by a particular user logged into a linux server during a given time interval ?
How do i determine the amount of network traffic to/from a particular user logged in on a linux system?
 
thanks and regards
Raghu

		
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