usermod [options] LOGIN

• modify a user account 更改用戶屬性

• usermod不允許你改變正在線上的使用者帳號名稱。當(dāng)usermod用來改變userID,必須確認(rèn)這名user沒在電腦上執(zhí)行任何程序

• 查看用戶配置 /etc/passwd user_name:x:uid:gid:commnet:home:shell

• 查看用戶組配置 /etc/shadow username:passwd:lastchg:min:max:warn:inactive:expire:flag

• 注意一旦使用-s /sbin/nologin指定用戶的bash為nologin,則代表該用戶不能登陸系統(tǒng)

• 常用選項(xiàng)

  -a:Add the user to the supplementary group 把用戶追加到某些組中,僅與-G一起使用 
  -d:HOME_DIR 修改用戶的家目錄通常和-m選項(xiàng)一起使用 
  -e:EXPIRE_DATE指定用戶帳號禁用的日期,格式Y(jié)Y-MM-DD 
  -f:INACTIVE 用戶密碼過期多少天后采用就禁用該帳號,0表示密碼已過期就禁用帳號,-1表示禁用此功能,默認(rèn)值是-1 
  -g:force use GROUP as new primary group 修改用戶的gid,改組一定存在
  -G:new list of supplementary GROUPS 把用戶追加到某些組中,僅與-a選項(xiàng)一起使用 
  -l:new value of the login name 修改用戶的登錄名稱 
  -L:lock the user account 鎖定用戶的密碼 
  -m:move contents of the home directory to the new location 修改用戶的家目錄通常和-d選項(xiàng)一起使用 
  -s:new login shell for the user account 修改用戶的shell 
  -u:new UID for the user account 修改用戶的uid,該uid必須唯一 
  -U:unlock the user account 解鎖用戶的密碼
  

1. 新建用戶test,密碼test,另外添加usertest組

   useradd test
   echo "test" | passwd --stdin test
   groupadd usertest
   

2. 把test用戶加入usertest組

   usermod -aG usertest test ##多個組之間用空格隔開 
   

3. 修改test用戶的家目錄

   usermod -md /home/usertest 
   

4. 修改用戶名

   usermod -l testnew(新用戶名稱)  test(原來用戶名稱) 
   

5. 鎖定testnew的密碼

   sed -n '$p' /etc/shadow 
     testnew:$6$1PwPVBn5$o.MIEYONzURQPvn/YqSp69kt2CIASvXhOnjv/t 
     Z5m4NN6bJyLjCG7S6vmji/PFDfbyITdm1WmtV45CfHV5vux/:15594:0:99999:7::: 
    usermod -L testnew 
    sed -n '$p' /etc/shadow 
     testnew:!$6$1PwPVBn5$o.MIEYONzURQPvn/YqSp69kt2CIASvXhOnjv/t 
     Z5m4NN6bJyLjCG7S6vmji/PFDfbyITdm1WmtV45CfHV5vux/:15594:0:99999:7::: 
   

6. 解鎖testnew的密碼

    usermod -U testnew 
    sed -n '$p' /etc/shadow 
     testnew:$6$1PwPVBn5$o.MIEYONzURQPvn/YqSp69kt2CIASvXhOnjv/t 
     Z5m4NN6bJyLjCG7S6vmji/PFDfbyITdm1WmtV45CfHV5vux/:15594:0:99999:7::: 
   

7. 修改用戶的shell

    sed '$!d' /etc/passwd 
     testnew:x:500:500::/home/usertest:/bin/bash 
    usermod -s /bin/sh testnew 
    sed -n '$p' /etc/passwd 
     testnew:x:500:500::/home/usertest:/bin/sh 
   

8. 修改用戶的UID

    usermod -u 578 testnew (UID必須唯一) 
    id testnew 
     uid=578(testnew) gid=500(test) groups=500(test),501(usertest) 
   

9. 修改用戶的GID

    groupadd -g 578 test1 
    usermod -g 578 testnew (578組一定要存在) 
    id testnew 
     uid=578(testnew) gid=578(test1) groups=578(test1),501(usertest) 
   

10. 指定帳號過期日期

    sed -n '$p' /etc/shadow 
     testnew:$6$1PwPVBn5$o.MIEYONzURQPvn/YqSp69kt2CIASvXhOnjv/t 
     Z5m4NN6bJyLjCG7S6vmji/PFDfbyITdm1WmtV45CfHV5vux/:15594:0:99999:7::: 
    usermod -e 2012-09-11 testnew 
    sed -n '$p' /etc/shadow 
     testnew:$6$1PwPVBn5$o.MIEYONzURQPvn/YqSp69kt2CIASvXhOnjv/t 
     Z5m4NN6bJyLjCG7S6vmji/PFDfbyITdm1WmtV45CfHV5vux/:15594:0:99999:7::15594: 
    

11. 指定用戶帳號密碼過期多少天后,禁用該帳號

    usermod -f 0 testnew 
    sed -n '$p' /etc/shadow 
     testnew:$6$1PwPVBn5$o.MIEYONzURQPvn/YqSp69kt2CIASvXhOnjv/t 
     Z5m4NN6bJyLjCG7S6vmji/PFDfbyITdm1WmtV45CfHV5vux/:15594:0:99999:7:0:15594: