File permission defines who can read and/or write to the file, and is the file executable or not.

To see a file permissions you can open the terminal and run the command (replace filename with the name of your file or directory)

ls -ld filename

result:

The string “drwxr-xr-x” is the file permission, let’s see what each letter represent

• The first character (d) indicates that it is a directory. If it were a regular file, it would be represented by (-).

The next three characters represent the permissions for the owner of the directory:

• rwx means the owner has read (r), write (w), and execute (x) permissions on the directory. The owner can view, modify, and navigate into the directory.

The next three characters represent the permissions for the group that the directory belongs to:

• r-x means the group has read (r) and execute (x) permissions, but does not have write (w) permission. The group members can list the contents of the directory and navigate into it, but cannot modify or create new files or directories within it.

The last three characters represent the permissions for other users (neither the owner nor part of the group):

• r-x means other users have read (r) and execute (x) permissions, but do not have write (w) permission. Other users can view the directory's contents and navigate into it, but cannot make changes to it.

So to read a file permission:

1. the first letter indicate the filetype
2. the next three letter indicate the owner permissions
3. the next three letter indicate the group permissions
4. the next three letter indicate others permissions
5. permissions letter are: r for read, w for write, x for execute