in reply to Sorting files

sure, decorate/sort/undecorate, see Understanding the Schwartzian transform., sorting type question- space problems

basically, tag every line with a calculated key ... for example turn 1.3 and x1.1y into 000001.000003 and x000001.000001y ... whatever makes the sense for the order you want

Then use the gnu sort or some other sort to sort your giant file