Published Book on Amazon
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All of IOT Starting with the Latest Raspberry Pi from Beginner to Advanced – Volume 1 |
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All of IOT Starting with the Latest Raspberry Pi from Beginner to Advanced – Volume 2 |
출판된 한글판 도서
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최신 라즈베리파이(Raspberry Pi)로 시작하는 사물인터넷(IOT)의 모든 것 – 초보에서 고급까지 (상) |
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최신 라즈베리파이(Raspberry Pi)로 시작하는 사물인터넷(IOT)의 모든 것 – 초보에서 고급까지 (하) |
Original Book Contents
13.1.3 Framework for Owner User and Owner Group of File
In Linux, users are grouped and managed according to certain criteria to grant or deny privileges to specific user account or user group of. When classifying the types of users who can be granted authority to files, there are three types as follows:
■ Owner user
It means a specific user account that has ownership of the file.
■ Owner group
It means a specific user group that has ownership of the file.
■ Other
It means all users except owner user and owner group.
For every file and directory on the system, a "owner user" with ownership is assigned to it, and a "owner group" with ownership is specified at the same time. All other users that don't belong to owner user or owner group belons to "other".
When a file is created on the system, the owner user and owner group are automatically assigned to the file. It is automatically specified as follows according to the user account of "working user" used when creating the file:
■ Owner user -- The user account of the working user is specified.
■ Owner group -- The primary group of the working user is specified.
For example, if a new file is created using the "pi" user account, "pi" is assigned to the owner user, and "pi" group defined as the primary group of the "pi" user is assigned to the group.