What are chmod commands and how do I use them?

What are chmod commands and how do I use them?

Chmod commands are used to change the permissions of files and directories in Unix-like operating systems. You can use it to set read, write, and execute permissions.

Can you explain the permission levels in chmod?

Sure! Chmod uses three permission levels: read (r), write (w), and execute (x). These can be set for the owner, group, and others.

How do I set permissions for a file to be readable and writable by the owner only?

You can use the command chmod 600 filename to set the file permissions to read and write for the owner only.

What does the numeric mode 755 mean?

The numeric mode 755 means the owner has read, write, and execute permissions (7), while the group and others have read and execute permissions (5).