Sorting number of lists according to indexes and priority

Question

I have a collection of lists with each containing around 6 to 7 values. Like,

list1 = 2,4,7,4,9,5
list2 = 4,3,7.3,9,8,1.2
list3 = 2,2.4,7,9,8,5
list4 = 9,1.6,4,3,4,1
list5 = 2,5,7,9,1,4
list6 = 6,8,7,2,1,5
list7 = 4,2,5,2,1,3

Now I want to sort these with index1 as primary and index3 as secondary and index2 as tertiary and so on. That is, the output should be like:

 2,2.4,7,9,8,5
 2,4,7,4,9,5
 2,5,7,9,1,4
 4,2,5,2,1,3
 6,8,7,2,1,5
 9,1.6,4,3,4,1

I want the list order to be sorted for index1 first and if the values are same for index1 than sorting is done on index3 and if further same than on index2. Here the number of lists are less which can increase to 20 and the indexes can grow up to 20 as well.

The algorithm I want to know is the same as that of iTunes song sorting, in which songs with the same album are sorted first and then by artist and then by rank and then by name. That's the album's if album names are the same then sorting is done on the artist if same, then by rank and so on. The code can be in C/C++/tcl/shell.

Answer 1

sort -n -t ',' -k 1 -k 3 -k 2

Feed the lists as individual lines into it.