Linux添加用户组和添加用户

Linux添加⽤户组和添加⽤户1.⽤户组
添加组：groupadd 组名
[root@Server-n93yom ~]# groupadd dev
[root@Server-n93yom ~]# cat /etc/group | grep dev
dev:x:10011:
[root@Server-n93yom ~]#
删除组：groupdel 组名
[root@Server-n93yom ~]# groupdel dev
[root@Server-n93yom ~]# cat /etc/group | grep dev
[root@Server-n93yom ~]#
查询组：cat /etc/group 或者使⽤管道来精确查询 cat /etc/group | grep dev
[root@Server-n93yom ~]# cat /etc/group
root:x:0:
bin:x:1:
daemon:x:2:
sys:x:3:
adm:x:4:
tty:x:5:
disk:x:6:
lp:x:7:
mem:x:8:
kmem:x:9:
wheel:x:10:
cdrom:x:11:
mail:x:12:postfix
man:x:15:
dialout:x:18:
floppy:x:19:
games:x:20:
tape:x:30:
video:x:39:
ftp:x:50:
lock:x:54:
audio:x:63:
nobody:x:99:
users:x:100:
utmp:x:22:
utempter:x:35:
ssh_keys:x:999:
input:x:998:
systemd-journal:x:190:
systemd-bus-proxy:x:997:
systemd-network:x:192:
dbus:x:81:
polkitd:x:996:
tss:x:59:
dip:x:40:
postdrop:x:90:
postfix:x:89:
sshd:x:74:
check:x:1000:check
cfyuser:x:10000:
consul:x:10002:
rabbitmq:x:10003:
mysql:x:10009:
prometheus:x:10004:
grafana:x:10005:
logstash:x:10006:
nginx:x:995:
tomcat:x:10008:
guanbin:x:10010:
dev:x:10011:
/etc ⽬录是专门⽤来保存系统配置信息的⽬录
group 是保存组信息的⽂件
2.⽤户
添加⽤户：useradd -m -g 组新建⽤户名注意：-m ⾃动建⽴⽤户家⽬录； -g 指定⽤户所在的组，否则会建⽴⼀个和⽤户名同名的组[root@Server-n93yom ~]# useradd -m -g dev test1
[root@Server-n93yom ~]#
dev为⽤户组，test1为⽤户名
查询⽤户：在/etc/passwd⽂件下存储的是⽤户的list
[root@Server-n93yom ~]# cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
games:x:12:100:games:/usr/games:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
nobody:x:99:99:Nobody:/:/sbin/nologin
systemd-bus-proxy:x:999:997:systemd Bus Proxy:/:/sbin/nologin
systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin
dbus:x:81:81:System message bus:/:/sbin/nologin
polkitd:x:998:996:User for polkitd:/:/sbin/nologin
tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
postfix:x:89:89::/var/spool/postfix:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
check:x:1000:1000:check:/home/check:/bin/bash
cfyuser:x:10000:10000::/home/cfyuser:/bin/bash
consul:x:10002:10002::/opt/cloudchef/consul:/sbin/nologin
rabbitmq:x:10003:10003::/etc/rabbitmq:/sbin/nologin
mysql:x:10009:10009::/home/mysql:/bin/bash
prometheus:x:10004:10004::/home/prometheus:/sbin/nologin
grafana:x:10005:10005::/home/grafana:/bin/bash
logstash:x:10006:10006::/home/logstash:/bin/bash
nginx:x:997:995:nginx user:/var/cache/nginx:/sbin/nologin
tomcat:x:10008:10008::/opt/cloudchef/tomcat:/sbin/nologin
test:x:10010:10010::/home/test:/bin/bash
test1:x:10011:10011::/home/test1:/bin/bash
只查找test1⽤户
[root@Server-n93yom ~]# id test1
uid=10011(test1) gid=10011(dev) groups=10011(dev)
[root@Server-n93yom ~]#
uid为⽤户id, gid为组id
修改和创建密码 passwd ⽤户名如果不加⽤户名则默认修改当前登录者的密码
[root@Server-n93yom ~]# passwd test1
Changing password for user test1.
New password:
BAD PASSWORD: The password is shorter than 8 characters
Retype new password:
passwd: all authentication tokens updated successfully.
[root@Server-n93yom ~]#
设置好密码后，使⽤此账号和密码登录
➜ ~ ssh test1@192.168.85.163
test1@192.168.85.163's password:
Last failed login: Mon Jul 2217:00:05 CST 2019from192.168.1.53 on ssh:notty There were 3 failed login attempts since the last successful login.
[test1@Server-n93yom ~]$
设置⽤户不能修改密码
[root@Server-n93yom ~]# passwd -l test1 //在root下，禁⽌test1⽤户修改密码的权限Locking password for user test1. //锁住test1不能修改密码
passwd: Success
[root@Server-n93yom ~]# su test1 //切换⽤户
[test1@Server-n93yom root]$ passwd //修改密码
Changing password for user test1.
Changing password for test1.
(current) UNIX password:
passwd: Authentication token manipulation error //没⽤权限修改密码
[test1@Server-n93yom root]$
清除密码
[root@Server-n93yom ~]# passwd -d test1 //删除test1的密码
Removing password for user test1.
passwd: Success
[root@Server-n93yom ~]# passwd -S test1 //查看test1的密码
test1 NP 2019-07-220999997 -1 (Empty password.) //密码为空
[root@Server-n93yom ~]#
passwd 帮助命令
[root@Server-n93yom ~]# passwd --help
Usage: passwd [OPTION...] <accountName>
-k, --keep-tokens keep non-expired authentication tokens
-d, --delete delete the password for the named account (root only)
-l, --lock lock the password for the named account (root only)
-u, --unlock unlock the password for the named account (root only)
-e, --expire expire the password for the named account (root only)
-f, --force force operation
-x, --maximum=DAYS maximum password lifetime (root only)
-n, --minimum=DAYS minimum password lifetime (root only)
-w, --warning=DAYS number of days warning users receives before password
expiration (root only)
-i, --inactive=DAYS number of days after password expiration when an account
becomes disabled (root only)
-S, --status report password status on the named account (root only)
--stdin read new tokens from stdin (root only)
Help options:
-?, --help Show this help message
--usage Display brief usage message
[root@Server-n93yom ~]#
3.设置密码失效时间
可以编辑/etc/.defs来设定⼏个参数，以后设置⼝令默认就按照参数设定为准：
PASS_MAX_DAYS 99999
PASS_MIN_DAYS 0
PASS_MIN_LEN 5
PASS_WARN_AGE 7
当然在/etc/default/可以找到如下2个参数进⾏设置：
# useradd defaults file
GROUP=100
HOME=/home
INACTIVE=-1
EXPIRE=
SHELL=/bin/bash
SKEL=/etc/skel
CREATE_MAIL_SPOOL=yes
通过修改配置⽂件，能对之后新建⽤户起作⽤，⽽⽬前系统已经存在的⽤户，则直接⽤chage来配置。

chage [选项] ⽤户名
chage命令是⽤来修改帐号和密码的有效期限。

-m：密码可更改的最⼩天数。

为零时代表任何时候都可以更改密码。

-M：密码保持有效的最⼤天数。

-w：⽤户密码到期前，提前收到警告信息的天数。

-E：帐号到期的⽇期。

过了这天，此帐号将不可⽤。

-d：上⼀次更改的⽇期。

-i：停滞时期。

如果⼀个密码已过期这些天，那么此帐号将不可⽤。

-l：例出当前的设置。

由⾮特权⽤户来确定他们的密码或帐号何时过期。

chage -l root 查root账号的信息
[root@Server-n93yom ~]# chage -l root
Last password change : Jul 22, 2019
Password expires : never
Password inactive : never
Account expires : never
Minimum number of days between password change : 0
Maximum number of days between password change : 99999
Number of days of warning before password expires : 7
[root@Server-n93yom ~]#
chage -M 60 test 设置密码过期时间为60天
chage -I 5 test 设置密码失效时间为5天
以test1账号为例，再查⼀次信息账号信息
[root@Server-n93yom ~]# chage -l test1
Last password change : Jul 22, 2019
Password expires : Sep 20, 2019
Password inactive : Sep 25, 2019
Account expires : never
Minimum number of days between password change : 0
Maximum number of days between password change : 60
Number of days of warning before password expires : 7
从上述命令可以看到，在密码过期后5天，密码⾃动失效，这个⽤户将⽆法登陆系统了。