请问在linux里面怎么新建一个用户？

************Create new user*************************
adduser penghan
passwd penghan
#Changing password for user penghan
New password: //input password
Retype new password: //input again
# Updated successfully //Over

********************Change default startup file***********
Method one:
which tcsh
# /bin/tcsh
chsh
# changing shell for penghan
Password: //input your password
New shell [/bin/tcsh]: /bin/tcsh
# Shell changed.
Method two:
Find a file "passwd" in /etc
Open it.
Find your user name,in which line
change "/bin/bash" to /bin/tcsh"

******************************************************
ok!You can start your icfb from your root.

#adduser username