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practice with linked list

just icyy (9)
I'm just doing some practice with linked list as to study and ran into a problem.
So far I have 4 functions: build a list forward, moving a node from front to back and deleting front, sorting an unsorted list, and a display. The first 2 functions work just fine, but when I execute the program the function to sort the list doesnt work and outputs the same thing as my function to move a node to the back. I don't know if it has something to do with the functions or if I just can't build an unordered LL in the same program as an ordered linked list. 

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#include <iostream>
#include <fstream>
using namespace std;

ifstream infile;

struct nodeType
{
	int info;
	nodeType *link;
};

void buildListFor(nodeType *&first, nodeType *&last);
void display(nodeType *first);
void front2back(nodeType *&first, nodeType *&last);
void sortList(nodeType *&first, nodeType *&last);

int main()
{
	infile.open("LLrac3info.txt");
	nodeType *first = NULL, *last = NULL;
	buildListFor(first, last);
	display(first);
	front2back(first, last);
	display(first);


	sortList(first, last);
	display(first);
}

void buildListFor(nodeType *&first, nodeType *&last)
{
	int digit;
	int count = 0;
	nodeType *newNode;
	infile >> digit;
	cout << "The list is: " << endl;
	while (!infile.eof())
	{
		newNode = new nodeType;
		newNode->info = digit;
		newNode->link = NULL;

		if (first == NULL)
		{
			first = newNode;
			last = newNode;
			count++;
		}
		else
		{
			last->link = newNode;
			last = newNode;
			count++;
		}
		infile >> digit;
	}
}
void display(nodeType *first)
{
	nodeType *current;
	current = first;
	while (current != NULL)
	{
		cout << current->info << endl;
		current = current->link;
	}
}
void front2back(nodeType *&first, nodeType *&last)
{
	cout << "The list after moving front to back and deleting front is: " << endl;
	nodeType *newNode;
	nodeType *temp = first;

	newNode = new nodeType;
	newNode->info = first->info;
	newNode->link = NULL;

	last->link = newNode;
	last = newNode;

	first = first->link;
	delete temp;
}
void sortList(nodeType *&first, nodeType *&last)
{
	cout << "The list aftr being sorted is: " << endl;
	nodeType *newNode;
	nodeType *current;
	nodeType *trail = NULL;
	bool found;
	int newItem;

	infile >> newItem;
	while (!infile.eof())
	{
		newNode = new nodeType;
		newNode->info = newItem;
		newNode->link = NULL;

		if (first == NULL)
		{
			first = newNode;
			last = newNode;
		}
		else
		{
			current = first;
			found = false;

			while (current != NULL && !found)
				if (current->info >= newItem)
					found = true;
				else
				{
					trail = current;
					current = current->link;
				}
			if (current == first)
			{
				newNode->link = first;
				first = newNode;
			}
			else
			{
				trail->link = newNode;
				newNode->link = current;

				if (current == NULL)
					last = newNode;
			}
		}
	}
}
cire (8284)
All sortList does currently is leak memory. The only way first and last are assigned a value is if they were null when the function was entered, and they are not.

Logically a function called sortList should sort a list that already exists. It should not be reading from a file (and, in fact, it probably doesn't since infile is a global stream that has already reached end-of-file.)
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