Setuid - Set User ID¶
The process's effective user ID gets set to that of the program file itself (rather than that of the user running it).
S- just the setuid bit
s- setuid bit and execute x
- Dir - No effect on DIRs
Setgid - Set Group ID¶
The process's effective group ID gets set to that of the program file (rather than that of the user's primary group).
- Dir - any files created in that directory will have the same group as that directory
r w x 4 2 1 = 7
chmod g-w ChangeLog chmod 744 ChangeLog