NET140 - Week Three

Linux Permissions

This week's reading was on permissions for Linux.

There are three types and groups of permissions. They types include: read, write and execute. The three groups are owner, group & all users.

When setting permissions for the owner, this applies to the owner of the directory. For group, it is those assigned to a directory. All users is exactly as it sounds, all users on the system. Read refers to viewing or reading the contents of the file or directory. Write is the permission for a user to write or modify the file or directory. Execute is the capability to execute the file.

These permissions can be designated in the CLI (Command Line Interface) in two ways. You can use the permission commands which is -rwxrwxrwx. The first set is for the owner, the second for the group and the last is all users.

To change them you would add a - to exclude the permission for the particular group. For instance, you want all users to only have read permissions, owner to have all permissions and group to have only read. So you would enter into CLI: -rwxr--r-- [filename]Permissions can also be entered into the CLI in shorthand - which is the octal form representing the binary values. This would be using values like 700 - which this would equate to the owner having (7 = 1,1,1) r,w & x permissions, while groups and all users (0,0,0) have none.

This chapter was fairly straight forward. You can see a lot of these permissions when working with files. Often I have seen the read and write from using word processor - where you can protect your file by making it read only or enabling a document to become writable.