Thanks for the replies!
I have found and installed 2.1.2, the latest available version I could find for ubuntu, but it also does not have search function. I guess I will wait for an ubuntu deb package for 2.1.3 to appear.
I did find a 2.1.3 deb, but it wouldn't install (uninstallable dependencies). In the meantime, doing searches with amulegui works fine in place of amulecmd with the same benefit: it starts up and shuts down without interrupting the core.

Thanks again.