Similar to the set user ID permission bit, there is a set group ID (SGID) permission bit. This bit allows a program to run as if it was a member of that group.
Let's look at one example:
$ ls -l /usr/bin/wall
-rwxr-sr-x 1 root tty 19024 Dec 14 11:45 /usr/bin/wall
We can see now that the permission bit is in the group permission set.
$ sudo chmod g+s myfile
$ sudo chmod 2555 myfile
The numerical representation for SGID is 2.
No exercises for this lesson.
What number represents the SGID?