Mark,

  Thanks for the help, but there are no lib files to attach to the project.
I've scaled down the code to a bare minimum just to show the linker problem
with the ReadLn function but don't see a way to post the code - is it
possible to post source files on this newsgroup ?

Regards,
ak

In the scaled down version, I only have 3 files : Form1.cpp, Lab Test 2.h, &
Form2.h . The contents of Form1.cpp are :

#include "stdafx.h"
#include "Form2.h"
#include <windows.h>

using namespace K1;

int APIENTRY _tWinMain(HINSTANCE hInstance,
                    HINSTANCE hPrevInstance,
                    LPTSTR    lpCmdLine,
                    int       nCmdShow)
{
    System::Threading::Thread::CurrentThread->ApartmentState =
System::Threading::ApartmentState::STA;
    Application::Run(new Form2());
    return 0;
}

                                        The contents of LabTest 2.h are :

#define MAX_DWELL_SAMPLES 1000              

typedef unsigned short ushort;

#pragma pack(1)

#pragma pack()

/*
***********************
** Function prototypes
***********************
*/

int  ReadLn(FILE *ifile, char line[]);

                                  & the contents of Form2.h are :

#pragma once
#include <stdio.h>
#include <windows.h>
#include <math.h>
#include <sys/timeb.h>
#include <time.h>
#include "LabTest 2.h"

namespace K1
{

using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;

int point_cnt = 0, dwell_samples = 0;  
char ifname[80];
FILE *sfile;
char   *timeline;
int    i, retries;
struct _timeb timebuffer;
BOOL   bStatus;

    /// <summary>
    /// Summary for Form2
    ///
    /// WARNING: If you change the name of this class, you will need to change
the
    ///          'Resource File Name' property for the managed resource
compiler tool
    ///          associated with all .resx files this class depends on.  
Otherwise,
    ///          the designers will not be able to interact properly with
localized
    ///          resources associated with this form.
    /// </summary>
    public __gc class Form2 : public System::Windows::Forms::Form
    {
    public:
        Form2(void)
        {
            InitializeComponent();
        }
       
    protected:
        void Dispose(Boolean disposing)
        {
            if (disposing && components)
            {
                components->Dispose();
            }
            __super::Dispose(disposing);
        }
    private: System::Windows::Forms::Button *  button1;

    private:
        /// <summary>
        /// Required designer variable.
        /// </summary>
        System::ComponentModel::Container* components;

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        void InitializeComponent(void)
        {
            this->button1 = new System::Windows::Forms::Button();
            this->SuspendLayout();
            //
            // button1
            //
            this->button1->Location = System::Drawing::Point(112, 112);
            this->button1->Name = S"button1";
            this->button1->Size = System::Drawing::Size(144, 48);
            this->button1->TabIndex = 0;
            this->button1->Text = S"test button";
            this->button1->Click += new System::EventHandler(this, button1_Click);
            //
            // Form2
            //
            this->AutoScaleBaseSize = System::Drawing::Size(5, 13);
            this->ClientSize = System::Drawing::Size(400, 254);
            this->Controls->Add(this->button1);
            this->Name = S"Form2";
            this->Text = S"Form2";
            this->ResumeLayout(false);

        }       

    private: System::Void button1_Click(System::Object *  sender,
System::EventArgs *  e)
            {

                            FILE *ifile;                         
                            int ret = FALSE, i, status;
                            char line[80];

                            ifile = fopen(ifname, "rt");      
                            if (ifile == NULL) printf("Unable to open %s\n", ifname);
                            else
                            {
                                status = ReadLn(ifile, line);
                                if (status) sscanf(line, "%d", &dwell_samples);         
                                if (dwell_samples > MAX_DWELL_SAMPLES) dwell_samples =
MAX_DWELL_SAMPLES;

                                i = 0;
                                status = ReadLn(ifile, line);
                                while (status)
                                {
                                status = ReadLn(ifile, line);
                                i++;
                                }
                                point_cnt = i;       
                                ret = TRUE;
                            }
                            fclose(ifile);
                           
            }

};

int ReadLn(FILE *ifile, char line[])           
{
 int status, i = 0;
 char buffer;

 status = fread(&buffer, 1, 1, ifile);
 while ((status) && (buffer != '\n') && (i < 80))
 {
 line[i++] = buffer;
 status  = fread(&buffer, 1, 1, ifile);
 }
 line[i] = 0;

 return status;
}

}

Regards,
ak