Understanding Directory Permission Strings

When you change the group ownership and permissions of a directory (e.g., /usr/src/k-ver/include), the permission string displayed by ls -ld will reflect these changes. Here’s how to interpret the permission string:

  1. File Type:

    • The first character indicates the type of file:

      • d: Directory

      • -: Regular file

      • l: Symbolic link

  2. Permissions:

    • The next 9 characters represent permissions for the owner, group, and others:

      • r: Read permission

      • w: Write permission

      • x: Execute permission (for directories, this means the ability to enter the directory).

  3. Owner and Group:

    • The owner and group are displayed after the permissions.

  4. Example Permission Strings:

    • Default permissions (before changes):

      drwxr-xr-x 2 root root 4096 Oct 10 12:34 /usr/src/k-ver/include

    • After changing group ownership:

      drwxr-xr-x 2 root developers 4096 Oct 10 12:34 /usr/src/k-ver/include

    • After granting group read permissions:

      drwxr-xr-x 2 root developers 4096 Oct 10 12:34 /usr/src/k-ver/include

    • After removing execute permissions for the group:

      drwxr--r-x 2 root developers 4096 Oct 10 12:34 /usr/src/k-ver/include