What is true about the owner of a file?
What is true about the owner of a file?
Each file is owned by exactly one user and one group. This ownership structure is fundamental to file systems in Unix-like operating systems. The owner of a file has specific permissions that can be set independently for the user, group, and others. While the owner can change these permissions, merely being the owner does not automatically grant full permissions. Other options provided either incorrectly describe these systems, like suggesting that the owner always has full permissions or that the owner cannot be changed, or describe behaviors not inherently true, such as assuming files disappear when a user is deleted.
Answer is A. C is not true, the file owner is independent of the file group D is not correct, deletion of user from system has no impact on the files on the system (unless a script is set up to trigger upon user deletion) E is true, a file's owner and group can be changed at any time by a user with sufficient privileges. B is the only one that is a bit confusing. Although the owner of a file can assign themselves full permissions, by default files will ordinarily not have the executable bit set, so for most files the owner will have read/write permissions only.
Answer is A.
A. Each file is owned by exactly one user and one group.
Here is a quick explanation for people like me who were initially confused about a file having only one group: In Unix-like operating systems, a file can have only one group owner. However, there is a feature called "file access control lists" (ACLs) that allows for more fine-grained control over file permissions and can be used to grant additional permissions to specific users or groups beyond the owner and group associated with the file. With ACLs, you can specify permissions for multiple users and groups on a file, providing more flexibility than the traditional owner-group-other model. ACLs enable you to set permissions for specific users or groups without changing the file's primary group ownership. It's important to note that while ACLs provide additional flexibility, they are not universally supported on all file systems or systems. Their availability depends on the specific operating system and file system in use. Additionally, managing permissions through ACLs can be more complex than using the standard owner-group-other model.