=== Immutable File Permissions ===
Chattr is a command that can be used to set file attributes that can prevent all users (even root) from deleting a file.
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== Viewing Immutable permissions ==
<sxh bash>
lsattr file
</sxh>
Example output of immutable file:
<sxh bash>
----i---------- filename
</sxh>
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== Setting file attributes with chattr ==
To prevent everyone (even root) from deleting a file:
<sxh bash>
chattr +i file
</sxh>
This will now make the file 'read-only'.
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To undo this:
<sxh bash>
chattr -i file
</sxh>
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== Restricting Editable files ==
You can use the +a attribute to allow users to append information into a file only:
<sxh bash>
chattr +a
</sxh>