/etc/login.defs
---------------------------
useradd footstep
/etc/passwd[- bak]
/etc/shadow[- bak] # man 5 shadow
/etc/group[- bak]
/etc/gshadow[- bak]
/home/footstep
/var/mail/footstep
cp -r /etc/skel/.* /home/footstep
chown -R footstep.footstep /home/footstep
-----------------------------
userdel -r footstep
-----------------------------
id # uid,gid,groups
users 顯示當前系統登陸的用戶
w 當前登錄本機的用戶及運行程序
last 查看用戶的登錄日誌
lastlog 查看每個用戶的登錄日誌
finger footstep 查看用戶信息plan,mail(yum install finger)