Linux设置(修改)用户密码命令-passwd

[root@localhost ~]# whoami
root
[root@localhost ~]# passwd 
Changing password for user root.
New password: 
BAD PASSWORD: The password fails the dictionary check - it is too simplistic/systematic
Retype new password: 
passwd: all authentication tokens updated successfully.

[root@localhost ~]# passwd user1
Changing password for user user1.
New password: 
Retype new password: 
passwd: all authentication tokens updated successfully.

[root@localhost ~]# passwd -S user1
user1 PS 2017-03-04 0 99999 7 -1 (Password set, SHA512 crypt.)

[v_blue]user1 PS 2017-03-04 0 99999 7 -1 (Password set, SHA512 crypt.)
格式：共八列，列与列之间用空格字符分隔
    第一列：用户名
    第二列：账户状态；PS为正常、LK为锁定
    第三列：系统当前时间
    第四列：密码最小使用天数(密码使用最小多少天才可更改密码)；默认为0则表示无限制(禁用此功能)
    第五列：密码最大使用天数(密码使用最大多少天需要更改密码)；默认为99999永不过期
    第六列：密码过期前警告天数(密码过期前多少天警告用户更改密码)；默认过期前7天警告
    第七列：密码过期天数(密码过期后多少天用户被锁定)；在此时间段内用户依然可以登录系统并更改密码
    第八列：密码配置状态及密码加密算法；Password locked表示密码已被锁定(账户密码未设置或账户已被锁定)，Password set表示密码已设置，SHA512 crypt表示使用SHA512算法[/v_blue]

[root@localhost ~]# passwd -l user1
Locking password for user user1.
passwd: Success
[root@localhost ~]# passwd -S user1
user1 LK 2017-03-04 0 99999 7 -1 (Password locked.)
[root@localhost ~]# grep user1 /etc/shadow
user1:!!$6$jxOh9OqV$57OBYLRy6/hfPtx1USHScB1L4ydHrsWmyt3elMcRfgb0s7FuxQgvYCIFPDecbjj6BmGb.7CkfB2cpDjtlrkdv/:18094:0:99999:7:::

[root@localhost ~]# passwd -u user1
Unlocking password for user user1.
passwd: Success[root@localhost ~]# passwd -S user1
user1 PS 2017-03-04 0 99999 7 -1 (Password set, SHA512 crypt.)[root@localhost ~]# grep user1 /etc/shadow
user1:$6$jxOh9OqV$57OBYLRy6/hfPtx1USHScB1L4ydHrsWmyt3elMcRfgb0s7FuxQgvYCIFPDecbjj6BmGb.7CkfB2cpDjtlrkdv/:18094:0:99999:7:::

[root@localhost ~]# passwd -n 10 user1
Adjusting aging data for user user1.
passwd: Success
[root@localhost ~]# passwd -S user1
user1 PS 2017-03-04 10 99999 7 -1 (Password set, SHA512 crypt.)

[root@localhost ~]# passwd -x 1000 user1
Adjusting aging data for user user1.
passwd: Success
[root@localhost ~]# passwd -S user1
user1 PS 2017-03-04 10 1000 7 -1 (Password set, SHA512 crypt.)

[root@localhost ~]# passwd -w 15 user1
Adjusting aging data for user user1.
passwd: Success
[root@localhost ~]# passwd -S user1
user1 PS 2017-03-04 10 1000 15 -1 (Password set, SHA512 crypt.)

[root@localhost ~]# passwd -i 30 user1
Adjusting aging data for user user1.
passwd: Success
[root@localhost ~]# passwd -S user1
user1 PS 2017-03-04 10 1000 15 30 (Password set, SHA512 crypt.)

[root@localhost ~]# passwd -S user2
user2 LK 2017-03-04 0 99999 7 -1 (Password locked.)
[root@localhost ~]# echo "123456"|passwd --stdin user2
Changing password for user user2.
passwd: all authentication tokens updated successfully.
[root@localhost ~]# passwd -S user2
user2 PS 2017-03-04 0 99999 7 -1 (Password set, SHA512 crypt.)