On Tue, Jan 05, 2021 at 10:38:39PM -0600, David Wright wrote: > But here on debian-user, I was really more interested in why the value > of DISPLAY was apparently changed by one su and not the other (or > perhaps by both). The explanation, "probably with an alias for su", > alias su="su -w DISPLAY", doesn't make any sense to me. Explanations?
"su" will leave the DISPLAY variable intact, and "su -" will remove it. I can see no evidence to the contrary, regardless of whether I'm using the ALWAYS_SET_PATH config variable. The behavior is simple and consistent for me. unicorn:~$ cat /etc/debian_version 10.7 unicorn:~$ dpkg -S /bin/su util-linux: /bin/su unicorn:~$ dpkg -l util-linux | tail -n1 ii util-linux 2.33.1-0.1 amd64 miscellaneous system utilities unicorn:~$ cat /etc/default/su ALWAYS_SET_PATH yes unicorn:~$ echo "$DISPLAY" :0 unicorn:~$ su Password: root@unicorn:/home/greg# echo "$DISPLAY" :0 root@unicorn:/home/greg# exit exit unicorn:~$ su - Password: root@unicorn:~# echo "$DISPLAY" root@unicorn:~# vi /etc/default/su root@unicorn:~# cat /etc/default/su # ALWAYS_SET_PATH yes root@unicorn:~# logout unicorn:~$ su Password: root@unicorn:/home/greg# echo "$DISPLAY" :0 root@unicorn:/home/greg# exit unicorn:~$ su - Password: root@unicorn:~# echo "$DISPLAY" root@unicorn:~# If someone is seeing DIFFERENT behavior than this, they have yet to demonstrate it for us.
