BTW - you know that 'printf' and 'fprintf to stdout' are essentially the same thing, right?

The matrix writer should take a file object pointer as an argument so you can pass it a handle to an open file to write it or pass it stdout to display it in your console. Then you should make a function to sort the matrix and one to write the matrix. The creation of the matrix should also be its own function and there needs to be a corresponding matrix free function the releases all the memory it allocated. I would make one function to read the file and create the matrix. This needs to be broken into a series of functions. This will also help you sort things out because you can focus on and debug one thing at a time. For this reason, I think you need to break this into functions.

That is only reasonable for the most trivial of programs and, in my opinion, your program is not quite trivial enough for that to be acceptable. What you have here is a monolithic program - there is one function. c file where the function is and also I use a makefile as well. There's no error code and I've tried everything. M = (int**) malloc(noOfRows * sizeof( int *))

Write in c