Linux Questions & Answers on File Permissions for Freshers

1. The file permission 764 means:

a) Every one can read, group can execute only and the owner can read and write
b) Every one can read and write, but owner alone can execute
c) Every one can read, group including owner can write, owner alone can execute
d) Every one can read and write and execute

Answer: c

2. The permission -rwxr–r– represented in octal expression will be

a) 777
b) 666
c) 744
d) 711

Answer: c

3. Effective user id can be set using following permission

a) 0777
b) 2666
c) 4744
d) 1711

Answer: c

4. Effective group id can be set using following permission

a) 0777
b) 2666
c) 4744
d) 1711

Answer: b

5. Sticky bit can be set using following permission

a) 0777
b) 2666
c) 4744
d) 1711

Answer: d

6. The permission -rwSr–r– represented in octal expression will be

a) 0777
b) 2666
c) 4744
d) 4644

Answer: d

7. The permission -rwxr-sr– represented in octal expression will be

a) 0777
b) 2766
c) 2744
d) 2754

Answer: d

8. If user tries to remove (rm) a readonly file (444 permission), what will happen?

a) The file is removed successfully (and silently)
b) The rm command prompts for a confirmation, the command is successful upon confirmation
c) The rm command prompts for a confirmation, however the operation fails because of insufficient permissions
d) The rm command fails because of insufficient permissions

Answer: b

9. A user does a chmod operation on a file. Which of the following is true?

a) The last accessed time of the file is updated
b) The last modification time of the file is updated
c) The last change time of the file is updated
d) None of the mentioned

Answer: c

10. If the umask value is 0002. what will be the permissions of new directory

a) 777
b) 775
c) 774
d) 664

Answer: b

11. What is the command to set the execute permissions to all the files and subdirectories within the directory /home/user1/direct

a) chmod –r +x /home/user1/direct
b) chmod –R +x /home/user1/direct
c) chmod –f –r +x /home/user1/direct
d) chmod –F +x /home/user1/direct

Answer: b

12. The permission -rwxr-xr-t represented in octal expression will be

a) 0777
b) 1755
c) 1754
d) 2754

Answer: b

13. With a umask value of 112, what is the default permission assigned to newly created regular file?

a) —x–x-wx
b) -rw-rw-r–
c) -r-xr-x-r–
d) -rw-rw-r–

Answer: d

14. Which command is used to assign read-write permission to the owner?

a) chmod a+r file
b) chmod o+r file
c) chmod u=rw file
d) chmod og-r file

Answer: c

15. Given the command
$ chmod o-w datafile

a) sets write permission to everyone for datafile
b) sets write permission to others for datafile
c) clears write permission to everyone for datafile
d) clears write permission to others for datafile

Answer: d

16. Which of these commands will set the permissions on file textfile to read and write for the owner, read for the group, and nothing for everyone else?

a) chmod 046 textfile
b) chmod 640 textfile
c) chmod 310 textfile
d) chmod rw r nil textfile

Answer: b

17. If you are a root user, how can you grand execute permission only for the owner of the file project1?

a) chmod +x project1
b) chmod u+x project1
c) chmod a+x project1
d) chmod U+X project1

Answer: b

18. A user executes the following command successfully:
$ chmod +x file1.txt
Which of the following is true of the output of this command?

a) The command results in adding execute permission to the user who ran this command
b) The command results in adding execute permission for the owner of the file
c) The command results in an error since the file is not an executable file
d) The command results in adding execute permission for all users (i.e., user,group & others)

Answer: d

19. What does chmod +t do?

a) wrong syntax
b) set effective userid for filename
c) set effective groupid for filename
d) set the sticky bit

Answer: d

20. Which of the following umask settings doesn’t allow execute permission to be set by default on directory files

a) 222
b) 111
c) 000
d) 444

Answer: c

21. Which of the following umask settings allow execute permission to be set by default on regular files

a) 222
b) 111
c) 000
d) None of the mentioned

Answer: d

22. The command chmod 4777 a.out

a) will set the suid bit of a.out
b) will set the suid bit of a.out only if the command is issued by root
c) is not a valid command
d) will set the sticky bit of a.out

Answer: a