Linux file Permissions

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Simulated environment three users

1, Master testhost simulation user

2. Family member Testauxiliary Simulation group

1 and 2 's family name Testgroup

3, Outsiders testout simulation other

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How do I modify a user group if the Testhost user already exists?

Usermod-g Testgroup Testhost

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Open four conversations for root,testhost,testauxiliary,testout users

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The following creates the file for simulation

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Three User environments view:

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three of them do not belong to root user,root group, so can only belong to this other inside (read and execute, not write)

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It can't be written with vim.

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The modified document is now owned by the owner and belongs to the group, instead

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and thenyou can write this file as a master (testhost).

Root can also

and then testauxiliary and testout still can't write .

One for group permissions and one for other permissions

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Testauxiliary belong to a group of permissions, did not write

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Testout belongs to other rights, not written

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Modify other user permissions under the current owner's user, or under root

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I can't even read it, but I can't do it without the permission of X.

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change the group to WX permission, no R

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I can't read it.

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The ability to write (edit) is to be forced to save, and not to see the previous. Can't do it.

and using the VIM editor will overwrite the original content, unless you use echo to go after the redirect

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deleting files

Controlled by permissions of the parent directory

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Can't delete

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Two graphs one meaning

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Although this file is testhost, deleting the file depends on the permissions of the parent directory.

and the parent directory is /testdir, and the master group is root.

Testhost can only be the permissions of other users, so it cannot be deleted.

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Now add additional user rights to the parent directory, plus w permissions

You can delete

See if other users can delete

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OK

Even if I do not have permission to the file, but I have the authority of the superior directory, you can delete

This article is from the "11745576" blog, please be sure to keep this source http://11755576.blog.51cto.com/11745576/1979380

Linux file Permissions