L1:新建用戶並加入組
# useradd student1
# groupadd caiwubu
# useradd -g caiwubu student2
# useradd -G caiwubu student3
# id student1
# id student2
# id student3
L2:更改用戶信息
# useradd student4
# id kuaiji4
# useradd -G caiwubu student4
# id student1
L3:其他用戶和組的操作
# userdel -r student4
# useradd -s /sbin/nologin student4
# useradd -d /ok test
# useradd -u 888 boss
# echo test | passwd --stdin test
# chage -l test
# chage -d 0 test
# chage -E 2015-10-01 test