#useradd命令：建立用户帐号和创建用户的起始目录，使用权限是超级用户
[root@VM_168_102_centos ~]# useradd test [root@VM_168_102_centos ~]# id test uid=502(test) gid=502(test) groups=502(test) [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd test:x:502:502::/home/test:/bin/bash
useradd –u UID：创建用户时直接指定UID
[root@VM_168_102_centos ~]# useradd -u 888 test_1 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd test_1:x:888:888::/home/test_1:/bin/bash
useradd –g GID：创建用户时直接指定GID，GID要事先存在
[root@VM_168_102_centos ~]# useradd -g 500 test_2 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd test_2:x:889:500::/home/test_2:/bin/bash [root@VM_168_102_centos ~]# id test_2 uid=889(test_2) gid=500(wanghan) groups=500(wanghan) [root@VM_168_102_centos ~]# useradd -g 777 test_3 useradd: group ‘777‘ does not exist
useradd –G GID：创建用户时直接指定额外组，但组要事先存在
[root@VM_168_102_centos ~]# useradd -G 500 test_3 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd test_3:x:890:890::/home/test_3:/bin/bash [root@VM_168_102_centos ~]# id test_3 uid=890(test_3) gid=890(test_3) groups=890(test_3),500(wanghan)
useradd –d：创建用户时指定用户主目录，如果此目录不存在，则同时使用-m选项，可以创建主目录
[root@VM_168_102_centos ~]# useradd -d /home/qidian -m test_6 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd test_6:x:893:893::/home/qidian:/bin/bash [root@VM_168_102_centos ~]# ls /home abc ceshi openstack qidian test test_1 test_2 test_3 wanghan
说明： –m：创建用户时，强制给用户创建主目录
useradd –M：创建用户，但不创建家目录
[root@VM_168_102_centos ~]# ls /home abc ceshi openstack qidian test test_1 test_2 test_3 wanghan [root@VM_168_102_centos ~]# useradd -M test_7 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd test_7:x:895:895::/home/test_7:/bin/bash [root@VM_168_102_centos ~]# ls /home abc ceshi openstack qidian test test_1 test_2 test_3 wanghan
useradd -c：创建用户指定一段注释性描述，在/etv/passwd中查看
[root@VM_168_102_centos ~]# useradd -c wanghan test_9 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd test_9:x:897:897:wanghan:/home/test_9:/bin/bash
useradd –s：创建用户时指定默认shell，应该指定/etc/shells文件出现的shell
[root@VM_168_102_centos ~]# useradd -s tcsh test_10 useradd: invalid shell ‘tcsh‘ [root@VM_168_102_centos ~]# useradd -s /bin/tcsh test_10 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd test_10:x:898:898::/home/test_10:/bin/tcsh
#groupadd命令：创建一个新组
[root@VM_168_102_centos ~]# groupadd hp [root@VM_168_102_centos ~]# tail -n 1 /etc/group hp:x:2001:
groupadd –g GID：创建新组并指定GID
[root@VM_168_102_centos ~]# groupadd -g 2000 wudi [root@VM_168_102_centos ~]# tail -n 1 /etc/group wudi:x:2000: [root@VM_168_102_centos ~]#
#userdel命令：删除用户，默认保留家目录
[root@VM_168_102_centos ~]# userdel test_9 [root@VM_168_102_centos ~]# tail /etc/passwd test_1:x:888:888::/home/test_1:/bin/bash test_2:x:889:500::/home/test_2:/bin/bash test_3:x:890:890::/home/test_3:/bin/bash test_4:x:891:891::/home/abc:/bin/bash openstack:x:892:892::/home/openstack:/bin/bash test_6:x:893:893::/home/qidian:/bin/bash wanghan11:x:894:894::/tmp/wanghan:/bin/bash test_7:x:895:895::/home/test_7:/bin/bash test_8:x:896:896::/home/test_8:/bin/bash test_10:x:898:898::/home/test_10:/bin/tcsh [root@VM_168_102_centos ~]# ls /home abc ceshi openstack qidian test test_1 test_10 test_2 test_3 test_8 test_9 wanghan
userdel -r：删除用户同时删除其家目录
[root@VM_168_102_centos ~]# userdel -r test_8 [root@VM_168_102_centos ~]# tail /etc/passwd test:x:502:502::/home/test:/bin/bash test_1:x:888:888::/home/test_1:/bin/bash test_2:x:889:500::/home/test_2:/bin/bash test_3:x:890:890::/home/test_3:/bin/bash test_4:x:891:891::/home/abc:/bin/bash openstack:x:892:892::/home/openstack:/bin/bash test_6:x:893:893::/home/qidian:/bin/bash wanghan11:x:894:894::/tmp/wanghan:/bin/bash test_7:x:895:895::/home/test_7:/bin/bash test_10:x:898:898::/home/test_10:/bin/tcsh [root@VM_168_102_centos ~]# ls /home abc ceshi openstack qidian test test_1 test_10 test_2 test_3 test_9 wanghan
#groupdel命令：删除群组，若组中仍包括某些用户，则必须先删除这些用户后，方能删除群组。
[root@VM_168_102_centos ~]# groupdel user1 groupdel: cannot remove the primary group of user ‘user1‘ [root@VM_168_102_centos ~]# groupdel wudi [root@VM_168_102_centos ~]# cat /etc/group | grep "wudi" [root@VM_168_102_centos ~]#
#passwd命令：设定用户密码
管理员修改自身密码：
[root@VM_168_102_centos ~]# passwd Changing password for user root. New password: Retype new password: passwd: all authentication tokens updated successfully.
管理员修改其他用户密码：
[root@VM_168_102_centos ~]# passwd wanghan Changing password for user wanghan. New password: Retype new password: passwd: all authentication tokens updated successfully.
用户修改自身密码：
[wanghan@VM_168_102_centos rott]$ passwd Changing password for user wanghan. Changing password for wanghan. (current) UNIX password: //输入当前密码 New password: Retype new password: passwd: all authentication tokens updated successfully.
passwd –l：锁定用户密码，用户不能修改密码
[root@VM_168_102_centos ~]# passwd -l wanghan Locking password for user wanghan. passwd: Success [root@VM_168_102_centos ~]# su wanghan [wanghan@VM_168_102_centos rott]$ passwd Changing password for user wanghan. Changing password for wanghan. (current) UNIX password: passwd: Authentication token manipulation error
passwd –u：解除用户密码锁定
[root@VM_168_102_centos ~]# passwd -u wanghan Unlocking password for user wanghan. passwd: Success [root@VM_168_102_centos ~]# su wanghan [wanghan@VM_168_102_centos rott]$ passwd Changing password for user wanghan. Changing password for wanghan. (current) UNIX password: New password:
passwd –S：显示用户密码简要信息
[root@VM_168_102_centos ~]# passwd -S wanghan
wanghan PS 2014-08-12 0 99999 7 -1 (Password set, SHA512 crypt.)
#usermod命令：用来修改用户帐号的各项设定
usermod –u UID：修改用户UID
[root@VM_168_102_centos ~]# id openstack uid=892(openstack) gid=892(openstack) groups=892(openstack) [root@VM_168_102_centos ~]# usermod -u 588 openstack [root@VM_168_102_centos ~]# id openstack uid=588(openstack) gid=892(openstack) groups=892(openstack)
usermod –g GID：修改用户GID
[root@VM_168_102_centos ~]# id wanghan uid=500(wanghan) gid=2000(wudi) groups=2000(wudi) [root@VM_168_102_centos ~]# usermod -g 2001 wanghan [root@VM_168_102_centos ~]# id wanghan uid=500(wanghan) gid=2001(hp) groups=2001(hp)
usermod –G GID：修改用户附加组，默认覆盖原有附加组，同时使用-a选项则是再额外添加
[root@VM_168_102_centos ~]# id user1 uid=899(user1) gid=899(user1) groups=899(user1),2000(wudi) [root@VM_168_102_centos ~]# usermod -G 2001 user1 [root@VM_168_102_centos ~]# id user1 uid=899(user1) gid=899(user1) groups=899(user1),2001(hp) [root@VM_168_102_centos ~]# usermod -a -G 2000 user1 [root@VM_168_102_centos ~]# id user1 uid=899(user1) gid=899(user1) groups=899(user1),2000(wudi),2001(hp)
usermod –c：修改用户帐号备注信息
[root@VM_168_102_centos ~]# useradd -c hello user2 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd user2:x:900:900:hello:/home/user2:/bin/bash [root@VM_168_102_centos ~]# usermod -c test user2 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd user2:x:900:900:test:/home/user2:/bin/bash
usermod -d：修改用户家目录，默认不会迁移家目录，同时使用-m则可迁移
[root@VM_168_102_centos ~]# usermod -d /tmp/wanghan user1 [root@VM_168_102_centos ~]# tail /etc/passwd test_2:x:889:500::/home/test_2:/bin/bash test_3:x:890:890::/home/test_3:/bin/bash test_4:x:891:891::/home/abc:/bin/bash openstack:x:588:892::/home/openstack:/bin/bash test_6:x:893:893::/home/qidian:/bin/bash wanghan11:x:894:894::/tmp/wanghan:/bin/bash test_7:x:895:895::/home/test_7:/bin/bash test_10:x:898:898::/home/test_10:/bin/tcsh user1:x:899:899::/tmp/wanghan:/bin/bash user2:x:900:900:test:/home/user2:/bin/bash [root@VM_168_102_centos ~]# usermod -d /tmp/user2/ -m user2 [root@VM_168_102_centos ~]# tail /etc/passwd test_2:x:889:500::/home/test_2:/bin/bash test_3:x:890:890::/home/test_3:/bin/bash test_4:x:891:891::/home/abc:/bin/bash openstack:x:588:892::/home/openstack:/bin/bash test_6:x:893:893::/home/qidian:/bin/bash wanghan11:x:894:894::/tmp/wanghan:/bin/bash test_7:x:895:895::/home/test_7:/bin/bash test_10:x:898:898::/home/test_10:/bin/tcsh user1:x:899:899::/tmp/wanghan:/bin/bash user2:x:900:900:test:/tmp/user2/:/bin/bash
usermod –s：修改用户shell
[root@VM_168_102_centos ~]# tail -n 1 /etc/passwd user2:x:900:900:test:/tmp/user2/:/bin/bash [root@VM_168_102_centos ~]# usermod -s /bin/tcsh user2 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd user2:x:900:900:test:/tmp/user2/:/bin/tcsh
usermod -l：修改用户帐号名称
[root@VM_168_102_centos ~]# tail -n 1 /etc/passwd user2:x:900:900:test:/tmp/user2/:/bin/tcsh [root@VM_168_102_centos ~]# usermod -l user3 user2 [root@VM_168_102_centos ~]# tail -n 1 /etc/passwd user3:x:900:900:test:/tmp/user2/:/bin/tcsh
usermod –L：锁定用户帐号密码，使其无效
[root@VM_168_102_centos ~]# usermod -L wanghan [root@VM_168_102_centos ~]# su wanghan [wanghan@VM_168_102_centos /root]$ passwd Changing password for user wanghan. Changing password for wanghan. (current) UNIX password: passwd: Authentication token manipulation error
usermod –U：解除锁定用户帐号密码
[root@VM_168_102_centos ~]# usermod -U wanghan [root@VM_168_102_centos ~]# su wanghan [wanghan@VM_168_102_centos /root]$ passwd Changing password for user wanghan. Changing password for wanghan. (current) UNIX password: New password:
#groupmod命令：修改群属性定义
groupmod –g GID：修改用户GID
[root@VM_168_102_centos ~]# cat /etc/group | grep "hp" hp:x:2004:user1 [root@VM_168_102_centos ~]# groupmod -g 2008 hp [root@VM_168_102_centos ~]# cat /etc/group | grep "hp" hp:x:2008:user1
groupmod -n：修改群组名称
[root@VM_168_102_centos ~]# cat /etc/group | grep "2008" hx:x:2008:user1 [root@VM_168_102_centos ~]# groupmod -n hp hx [root@VM_168_102_centos ~]# cat /etc/group | grep "2008" hp:x:2008:user1
#chage命令：修改帐号和密码的有效期限
chage –l：查看帐号密码的有效期限
Last password change : Aug 13, 2014 //最近一次修改密码 Password expires : never Password inactive : never Account expires : never Minimum number of days between password change : 0 //密码可更改的最小天数 Maximum number of days between password change : 99999 // 密码保持有效的最大天数 Number of days of warning before password expires : 7 //用户密码到期前，提前收到警告信息的天数
chage –m：设定密码可更改的最小天数
[root@VM_168_102_centos ~]# chage -m 5 wanghan [root@VM_168_102_centos ~]# chage -l wanghan Last password change : Aug 13, 2014 Password expires : Aug 23, 2014 Password inactive : never Account expires : never Minimum number of days between password change : 5
chage –M：设定密码有效的最大天数
[root@VM_168_102_centos ~]# chage -M 10 wanghan [root@VM_168_102_centos ~]# chage -l wanghan Last password change : Aug 13, 2014 Password expires : Aug 23, 2014 Password inactive : never Account expires : never Minimum number of days between password change : 5 Maximum number of days between password change : 10 Number of days of warning before password expires : 7
chage -E：设定帐号的到期日期，0是立即过期，-1永不过期
[root@VM_168_102_centos ~]# chage -E 0 wanghan [root@VM_168_102_centos ~]# chage -l wanghan Last password change : Aug 13, 2014 Password expires : Aug 23, 2014 Password inactive : never Account expires : Jan 01, 1970 //帐号过期日期
[root@VM_168_102_centos ~]# chage -E -1 wanghan [root@VM_168_102_centos ~]# chage -l wanghan Last password change : Aug 13, 2014 Password expires : Aug 23, 2014 Password inactive : never Account expires : never //帐号永不过期
chage –W：设定用户密码到期前，提前收到警告信息的天数
[root@VM_168_102_centos ~]# chage -W 5 wanghan [root@VM_168_102_centos ~]# chage -l wanghan Last password change : Aug 13, 2014 Password expires : Aug 23, 2014 Password inactive : never Account expires : never Minimum number of days between password change : 5 Maximum number of days between password change : 10 Number of days of warning before password expires : 5
#id命令：显示用户ID及所属群组ID
[root@VM_168_102_centos ~]# id uid=0(root) gid=500(wanghan) groups=500(wanghan) [root@VM_168_102_centos ~]# id wanghan uid=500(wanghan) gid=2008(hp) groups=2008(hp)
id -u：显示用户UID，跟-n一起使用则显示用户名
[root@VM_168_102_centos ~]# id uid=0(root) gid=0(root) groups=0(root) [root@VM_168_102_centos ~]# id -u 0 [root@VM_168_102_centos ~]# id -u -n root
id -g：显示基本组ID，跟-n一起使用则显示其基本组名
[root@VM_168_102_centos ~]# id wanghan uid=500(wanghan) gid=2008(hp) groups=2008(hp) [root@VM_168_102_centos ~]# id -g wanghan 2008 [root@VM_168_102_centos ~]# id -g -n wanghan hp
id –G：显示所有组ID，跟-n一起使用则显示所有组名
[root@VM_168_102_centos ~]# id user1 uid=899(user1) gid=899(user1) groups=899(user1),2008(hp) [root@VM_168_102_centos ~]# id -G user1 899 2008 [root@VM_168_102_centos ~]# id -G -n user1 user1 hp
原文地址：http://putongren.blog.51cto.com/9086263/1539263
