So, found myself installing IRAF on a friend's laptop running Ubuntu. There are some decent tutorials online about the general steps: for example, this one, and the official one. However, they all skip all possible issues that could come up (or at least, that popped up in my case). This …

Need to convert a base 10 integer in a base 2 one? Or, at any rate, convert a number from one numeration system to another? In Ubuntu, the bc utility already integrates these features. It is usually already installed, so you don't have to anything special.

Simply run bc, and …