Run a file as root irrespective of who is running it.
It is a file permission, delegated as `s` allowing current user to execute that file as root. Yeah, kinda like a sudo
To set up setuid:
touch delete.sh
@: ls -l
- rw-r--r-- 1 niva niva 0 Dec 5 17:54 delete.sh
chmod u+s delete.sh
@: ls -l
- rwSr--r-- 1 root root 0 Dec 5 17:54 delete.sh
Obeserve here the letter capital `S`. This means setuid is set, but the user that owns the file does not have execute permissions.
So, file to be executable by user do;
chmod u+x delete.sh
- rwsr--r-- 1 root root 0 Dec 5 17:54 delete.sh
