Permisos 🌵

• Nmonic : 421 ugo

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

http://www.tutonics.com/2012/12/linux-file-permissions-chmod-umask.html

Permission Flags

r w x
4 2 1 = 7

Changing Permissions

chmod g-w ChangeLog
chmod 744 ChangeLog