Linux system Configuration and service Management _ No. 03 Chapter User Management

Hello everyone, I am a bully, yesterday because the work of things, forget more, this morning to make up yesterday's article, weekly Saturday Sunday stop more than two days.

1. User/Group Basic concept: ① concept: Users and Groups:
. Every process (running program) on the system runs as a particular user.
. Every file is owned by a particular user.
. Access to files and directories is restricted by user.
. The user associated with a running process determines the files and directories accessible to that process.
② view current logged-on user information:

                                                               ③ view file owner:[[email protected] ~]# ll/home/ DRWX------. 4 Alice Alice 4096 June 2 15:59 Alice drwx------ . 2 root root 16384 June 1 23:09 lost+found drwxr -xr-x 2 root root 4096 June 2 15:33 Tianyun④ view Run process                                                                            Username:user PID%cpu%MEM VSZ RSS TTY STAT START time COMMAND Root 1 0.0 0.0 19360 1536? Ss 13:29 0:00/sbin/init root 2 0.0 0.0 0 0 ? S 13:29 0:00 [Kthreadd] Root 3 0.0 0.0 0 0? S 13:29 0:00 [MigraTION/0] Root 4 0.0 0.0 0 0? S 13:29 0:00 [ksoftirqd/0]

2. User/Group Management: First of all, we are talking about users such as

Then the user group: the user group is divided into basic groups and additional groups
1 Creating a user
#useradd TestA
#useradd TESTB

2 View User Uid/gid
#cat/etc/passwd
testa:x:1000:1000 (uid:gid-Basic Group ID)
testb:x:1001:1001

3 Create a new group with a query group ID of 1002.
#groupadd Groupt
#cat/etc/group
GOUTPT::1002:

4 Please modify the user's base group to 1002 with "Usermod-g".
#usermod-G Groupt TestA

5 Querying user gid, from 1000 to 1002
#cat/etc/passwd
TESTA:X:1000:1002 (uid:gid-Basic Group ID)
testb:x:1001:1001

Additional groups: 1 creating users
#useradd TestA
#useradd TESTB
2 Viewing Group information
#cat/etc/group
TESTA::1001:
TESTB::1002:
3 Join the user to another group.
Syntax-G Append Group group name User name
Usermod-g Testb TestA
4 Viewing the members of additional groups
#cat/etc/group
TESTA::1001:
Testb::1002:testa (user)

Right (understanding): This part of the people understand that you can,

                                **今天的文章就到这里了，感谢大家的支持，在这里给大家道个歉，因为本人感冒，文章内容结构会整理的不太好，请大家多多包容，谢谢大家，明天见。**

Linux system Configuration and service Management-No. 03 Chapter user Management