su: permission denied error

By using command prompt access the device shell/terminal. then use the su command getting permission denied error. Why this happening?

how can i solve this pro开发者_开发知识库blem.

Well, i have hear'd of it, don't know exactly, but i think one needs to root the device in order to get those privileges......

First try

shell>man su

The command su take some parameters like -l after that you have to enter the user password. If you type:

su -l root

then the root password is going to be asked. Probably you can cope your problem by using the "sudo" command. (try "man sudo").