Need help in programming language "C",(only C not C# or no c++)

For this homework, you will be making a command line utility, columnSorter. This program will require one command line parameter, the number of a column. This program will read input data on stdin, saving each line it reads in a list. It will then sort the list based on the values in the indicated column, then it will write all of the data out to stdout.

The input data should be in the form of CSV (comma-separated-value). Each line can be divided into a number of columns, being split at commas. We have a couple of simplifications here, just to make this problem a little more manageable:

1. Every line has the same number of columns

2. All of the entries are simple values, integers or words. The text values aren't quoted, and there are no commas inside a value.

Here is a short example of some input:

Sam,15,banana

Julie,23,grape

Scott,12,kiwi

If the program was asked to sort by column 1 (the names), the output would be:

Julie,23,grape

Sam,15,banana

Scott,12,kiwi

but if the program was asked to sort by column 2 (the numbers), the output would be:

Scott,12,kiwi

Sam,15,banana

Julie,23,grape

Your program should use at least one structure, and should have at least a couple of functions.