if you have a "" on your system, you can use
pacman -Qo <file name>
to look up, which package owns the "" in /usr/bin/ directory.
in your case, this does not help.
if you want to list, what files a package installs on your system, you can use (depending on, whether it is a local package you are looking for or not:
pacman -Ql <PACKAGE NAME>
sudo pacman -Fyl <PACKAGE NAME>
if you want to search for a package, which installs a certain file on your system, you can use:
pacman -Ql | grep <FILE NAME>
sudo pacman -Fysx <FILE NAME>
in your case,
sudo pacman -Fysx domainname
gives you a solution: the inetutils package installs a "dnsdomainname" file in usr/bin/ (all files in this directory will automatically get added to your PATH and you can start them without specifying their full path).
i am not sure, whether it is thing you are looking for.
one more point:
there is a package called yp-tools in the AUR. it might be worth checking out.
pacui is a script i have written, which does all of this for you. simply chose "list package files" or "search package files". it automatically searches all files/packages on your system and on the manjaro repositories. it is not possible to do these searches for AUR packages.
“search package files” finds ALL files you are looking for (and which get installed by packages), even .so files and other stuff. if you want to limit your search results to files, which you can actually execute, i strongly recommend to filter your search results for files contained in the usr/bin/ directory (simply start typing and pacui will filter the list you are seeing)!
"list package files" automatically filters the search results for usr/bin/. if you want to see all search results, delete the filter by using the backspace key.