File Permissions and Ownership Flashcards

What numeric permission value represents rwxr-x---?

Answer: 750

rwx=7, r-x=5, ---=0, so the octal value is 750.

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

Answer: Both A and B

Both 'chgrp devs file.txt' and 'chown :devs file.txt' change only the group ownership.

A file has permissions -rw-rw-r--. Which class has write access?

Answer: Owner and group

rw- for owner and rw- for group means both owner and group have write access; others have read-only.

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

Answer: Prevents users from deleting files they do not own

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

Which symbolic permission argument adds execute permission for all users?

Answer: a+x

'a' stands for all (user, group, others), so 'a+x' adds execute for everyone.

What is the default umask value for a regular user on most Linux systems?

Answer: 0022

The default umask for regular users is typically 0022, resulting in files with 644 and directories with 755.

A file is owned by user 'alice' and group 'staff'. The current user is 'bob', who is in the 'staff' group. The file permissions are rw-r--r--. Can bob write to the file?

Answer: No, bob can only read it via group permissions

The group permission is r-- (read-only), so bob, matched as a group member, can only read the file.