SUID (Set User ID on execution) and GUID (Group User ID on execution) that uses to give execution permission for running as owner of file.
example of activated suid
passwd command;
ls -l /usr/bin/passwd
-rwsr-xr-x
example of activated guid
wall command;
ls -l /usr/bin/wall
-r-xr-sr-x
info: "s" means that the file is activated for suid or guid.
to activate suid;
chmod u+s myfile.txt
to deactivate suid;
chmod u-s myfile.txt
to activate guid;
chmod g+s myfile.txt
to deactivate guid;
chmod g-s myfile.txt
You may also want to read this entry; http://ozsoyler.blogspot.com/2014/11/what-is-sticky-bit.html
example of activated suid
passwd command;
ls -l /usr/bin/passwd
-rwsr-xr-x
example of activated guid
wall command;
ls -l /usr/bin/wall
-r-xr-sr-x
info: "s" means that the file is activated for suid or guid.
to activate suid;
chmod u+s myfile.txt
to deactivate suid;
chmod u-s myfile.txt
to activate guid;
chmod g+s myfile.txt
to deactivate guid;
chmod g-s myfile.txt
You may also want to read this entry; http://ozsoyler.blogspot.com/2014/11/what-is-sticky-bit.html