Linux Permissions 2

Question 1

What does the sticky bit do when set on a directory?

Accepted Answer

Prevents users from deleting files they do not own

Answer

The sticky bit on a directory restricts file deletion so only the file owner, directory owner, or root can remove files.

Question 2

Which octal value represents rwxr-x--- for a file?

Accepted Answer

750

Answer

rwx=7 for owner, r-x=5 for group, ---=0 for others gives octal 750.

Question 3

What is the effect of the setgid bit on a directory?

Accepted Answer

New files inherit the directory's group ownership

Answer

When setgid is set on a directory, newly created files and subdirectories inherit the directory's group rather than the creator's primary group.

Question 4

A file has permissions -rw-rw-r--. What is the umask that likely produced this from a default of 666?

Accepted Answer

002

Answer

A umask of 002 subtracts write permission from others (666 - 002 = 664, i.e., rw-rw-r--).

Question 5

Which command changes the group ownership of a file to 'devs'?

Accepted Answer

Both A and B

Answer

Both `chgrp devs file.txt` and `chown :devs file.txt` correctly change the group ownership of a file.

Linux Practice Test