Linux相关命令整理

用户管理命令 

1.groupadd(添加组)

 

Usage: groupadd [options] GROUP

Options:
-f, --force exit successfully if the group already exists,
and cancel -g if the GID is already used
-g, --gid GID use GID for the new group(指定组id)
-h, --help display this help message and exit
-K, --key KEY=VALUE override /etc/login.defs defaults
-o, --non-unique allow to create groups with duplicate
(non-unique) GID
-p, --password PASSWORD use this encrypted password for the new group
-r, --system create a system account(创建系统组)
-R, --root CHROOT_DIR directory to chroot into

 

2.groupdel(删除组)

Usage: groupdel [options] GROUP

Options:
-h, --help display this help message and exit
-R, --root CHROOT_DIR directory to chroot into

3.useradd(创建一个新用户或更新默认新用户信息)

Usage: useradd [options] LOGIN
useradd -D
useradd -D [options]

Options:
-b, --base-dir BASE_DIR base directory for the home directory of the
new account
-c, --comment COMMENT GECOS field of the new account
-d, --home-dir HOME_DIR home directory of the new account
-D, --defaults print or change default useradd configuration
-e, --expiredate EXPIRE_DATE expiration date of the new account
-f, --inactive INACTIVE password inactivity period of the new account
-g, --gid GROUP name or ID of the primary group of the new
account
-G, --groups GROUPS list of supplementary groups of the new
account
-h, --help display this help message and exit
-k, --skel SKEL_DIR use this alternative skeleton directory
-K, --key KEY=VALUE override /etc/login.defs defaults
-l, --no-log-init do not add the user to the lastlog and
faillog databases
-m, --create-home create the user's home directory
-M, --no-create-home do not create the user's home directory
-N, --no-user-group do not create a group with the same name as
the user
-o, --non-unique allow to create users with duplicate
(non-unique) UID
-p, --password PASSWORD encrypted password of the new account
-r, --system create a system account
-R, --root CHROOT_DIR directory to chroot into
-s, --shell SHELL login shell of the new account
-u, --uid UID user ID of the new account
-U, --user-group create a group with the same name as the user
-Z, --selinux-user SEUSER use a specific SEUSER for the SELinux user mapping

useradd和adduser命令相同,adduser是useradd的软连接

(1)用户的分类

  超级用户:root,拥有对系统的最高管理权限,UID默认为0。

  虚拟用户:又叫系统用户或伪用户,具有一定特权,与系统或程序服务相关,但没有真正的使用者。一般不会用来登录系统,它主要用于维持某个访问的正常运行,如ftp,apache等。

  普通用户:是一种受限制的用户,一般新建的用户都是普通用户。默认只能执行/bin、/usr/bin、/usr/local/bin以及自身主目录里的命令。

  在CentOS7中系统用户UID为1~999,普通用户UID为1000+;以前的CentOS6中系统用户UID为1~499,普通用户UID为500+

  注意:UID即每个用户的身份标识,虽然可以修改/etc/passwd(命令设置的UID不允许重复),但尽量保持唯一性,类似于每个人的身份证号码

 

#添加hadoop用户 useradd hadoop

4.userdel(删除一个用户)

(1)userdel 用户名(功能描述:删除用户但保存用户主目录 /home/用户名)

(2)userdel -r 用户名(功能描述:用户和用户主目录,都删除)

5.passwd(操作用户密码)

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

#更改hadoop的密码    passwd hadoop

 

6.su(切换用户)

su 用户名

7.id(判断用户是否存在)

uid=0(root) gid=0(root) groups=0(root) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

 

8.who(查看登陆用户信息)

(1)whoami  (功能描述:显示自身用户名称)

(2)who am i  (功能描述:显示登录用户的用户名)

(3)who   (功能描述:看当前有哪些用户登录到了本台机器上)

 

 

 

 

 

posted on 2019-07-14 16:14  bdcyouth  阅读(27)  评论(0编辑  收藏

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