Salix OS

I've just installed salix64-ratpoison-14.0.1 (this is my first time with slackware). For some reason, sudo appears to be not working. For example, when I do:
$ sudo slapt-get -u
it says something like "slapt-get: command not found". However, slapt-get works after switching to root (good ol' su). Same happens with shutdown command too. I've added my username to both sudo and wheel groups, uncommented corresponding lines from /etc/sudoer but nothing seems to work. Any ideas?
(btw, I installed the official ISO, matched the md5 and used unetbootin to create installation USB in case it matters).

Salix moved to sudo with its 14.1 release; earlier versions use su + root password. I imagine it's quite easy to set it up to work with sudo if you want, but I'm not sure how off the top of my head, and also, there may be a few wrinkles.

Incidentally, the ratpoison edition includes the commands rpshutdown and rpreboot, accessed from the menu or terminal, which shouldn't require root privileges.

I think you must use full path to file

sudo /usr/sbin/slapt-get

or update PATH in /etc/profile or add in ~/.bashrc.

No, you don't need to do that. sudo is not set up in Ratpoison or any Salix edition prior to 14.1.