Bash: sorting by two fields

[humbletech99]

I am using bash and need to sort a bunch of numbers that look like the following example:

9.1
9.2
...
9.N
10.1
10.2
...
10.N

I am having trouble because the sort command either sorts by one field or the other, so if I just | sort -n I end up with

9.1
9.20
9.21
...
9.2
9.30
9.31
...
9.3
...
10.1
10.20
10.21
...
10.2

Does anyone have a cunning way of sorting by field one and then subsorting by field 2 without losing the order of the first field? If I sort by field 2 then of course the 9 and 10 at the beginning would could out of order.

[likwid]

I don't understand the problem. What is your desired output?

[humbletech99]

I wanted to make .5 come before .40 because I am sorting IP addresses.

It is ok, there is a little used switch -k which did what I wanted.

[likwid]

I think the search key switch is one of the most used, besides -n. At least, in my Linux scripts it is. Problem is, -k isn't portable. Well, it's only a problem if you intend on running the script on anything besides Linux that isn't using GNU sort.

[likwid]

Actually, scratch that, I think it's the modifiers that may behave differently, that are sometimes used in conjunction with -k.