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
13.2 Changing Permission on File
13.2.1 Changing Owner User and Owner Group of File
13.2.1.1 "chown" Command – Change Owner User of File
To change the owner user of a file, use the "chown" command. You can change the owner user information, and if necessary, change the owner group for the file at the same time.
[Command Format]
| chown [OPTION]... [OWNER] [:[GROUP]] FILE... |
[Command Overview]
■ This changes the owner user of a file.
■ User privilege -- Super user.
[Detail Description]
■ This command changes the owner user and owner group for a specific file. You can change only the owner user, or change the owner group together.
■ When changing a owner group, execute the command in the format ": group name". If you specify only a colon (:) and do not specify a group name, it is changed to the primary group of the owner user.
[Main Option]
| --help | display this help and exit |
| -R, --recursive | operate on files and directories recursively When working on a directory, all of the subdirectorys and files under the directory are changed at once |
[Used Example]
To change the owner user of directory "manual01" to "root", do the following task.
| pi@raspberrypi ~ $ sudo chown root ./testdata/manual01 |
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If you view the details of the file again after the operation is completed, you can see that the owner for "manual01" has been changed to "root".
| pi@raspberrypi ~ $ ls ./testdata/ -l |
| total 16 drwxr-xr-x 2 root pi 4096 Mar 24 02:26 manual01 drwxr-xr-x 2 pi pi 4096 Mar 24 02:26 manual02 -rw-r--r-- 1 pi pi 18 Mar 24 02:10 user_guide01.txt -rw-r--r-- 1 pi pi 18 Mar 24 02:10 user_guide02.txt |
13.2.1.2 "chgrp" Command - Change Owner Group of File
Owner group of a file can be changed using the "chgrp" command.
[Command Format]
| chgrp [OPTION]... GROUP FILE... |
[Command Overview]
■ This changes the owner group of a file
■ User privilege -- Super user.
[Detail Description]
■ None
[Main Option]
| --help | display this help and exit |
| -R, --recursive | operate on files and directories recursively When working on a directory, all of the directorys and files under the directory are changed at once |
[Used Example]
To change the owner group for directory "manual01" to "root", do the following task.
| pi@raspberrypi ~ $ sudo chgrp root ./testdata/manual01 |
If you check the details of the file again after the operation is completed, you can see that the owner group for "manual01" has been changed to "root".
| pi@raspberrypi ~ $ ls ./testdata/ -l |
| total 16 drwxr-xr-x 2 root root 4096 Mar 24 02:26 manual01 drwxr-xr-x 2 pi pi 4096 Mar 24 02:26 manual02 -rw-r--r-- 1 pi pi 18 Mar 24 02:10 user_guide01.txt -rw-r--r-- 1 pi pi 18 Mar 24 02:10 user_guide02.txt |