Podcast Beta
Questions and Answers
What does a umask value of 002 mean for new files created in the system?
Which chmod command would you use to grant read, write, and execute permissions to the owner, and only read permissions to the group and others?
What octal value represents having no permissions at all?
When the default umask is set to 000, what will be the default permissions for a newly created directory?
Signup and view all the answers
What is the effect of the command 'chmod 644 practice' on the permissions of the file named 'practice'?
Signup and view all the answers
What does the 'd' at the beginning of the mode field indicate?
Signup and view all the answers
What characters in the mode field represent the permissions for the user (owner) of the file?
Signup and view all the answers
How would you add read permission for the user (owner) of a file named 'list1' using chmod?
Signup and view all the answers
In the command 'chmod g-w list1', what is the effect of this command?
Signup and view all the answers
Which of the following best describes what the 'chmod' command does?
Signup and view all the answers
What does the last three characters in the mode field represent?
Signup and view all the answers
If a file's permission string is 'rw-r--r--', which of the following groups has write permission?
Signup and view all the answers
When using symbolic values with chmod, what does the '+' symbol signify?
Signup and view all the answers
What is the effect of using the command 'chmod a-rwx practice'?
Signup and view all the answers
Which command would you use to allow write permission for the group and others in a directory named 'docs'?
Signup and view all the answers
What happens when the command 'chmod u-x sport' is executed and the user tries to enter the 'sport' directory?
Signup and view all the answers
If 'r', 'w', and 'x' respectively represent read, write, and execute permissions, what does the octal representation of 'rwx' equal?
Signup and view all the answers
What command correctly sets the permissions of a file to allow read and write access for all users while removing execute permission?
Signup and view all the answers
When using octal values with the chmod command, which represents no permissions?
Signup and view all the answers
What is the outcome of executing 'chmod go-w practice' on the directory?
Signup and view all the answers
To set only read permission for the group on a file named 'file.txt', which command should you use?
Signup and view all the answers
Study Notes
File and Directory Permissions
- The mode field in the
ls -l
command output shows file permissions. - A "d" at the start of the mode field indicates a directory, a "-" shows a file, and an "l" signifies a link to another file.
- The mode field has three sections: user, group, and others, each with read, write, and execute permissions represented by "r", "w", and "x".
- Hyphens within the mode field indicate that a permission is not granted.
The chmod Command
- The
chmod
command changes file or directory permissions. - It can be used with symbolic or octal values.
- Symbolic specifications include class of user (u, g, o, a), how permissions are changed (+, -, =), and permissions (r, w, x).
- Octal specifications use a 3-digit number representing the combined permissions (read = 4, write = 2, execute = 1).
The umask Command
- The
umask
command controls the default permissions given to newly created files and directories. - The system administrator usually sets the initial umask value.
- The initial umask is typically 000, resulting in default directory permissions of 777 (rwxrwxrwx).
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers essential aspects of file and directory permissions in Linux, including the interpretation of the 'ls -l' command and the application of 'chmod' and 'umask' commands. Test your understanding of how to manage user, group, and others' permissions effectively within a Linux environment.