#include <stdio.h>

#define MAX_CHARS_PER_LINE 100

int main ()
{
  int lineNumber;                           // We'll track line numbers.
  char inputLine [MAX_CHARS_PER_LINE + 1];  // Need an extra char for string-terminator.
  char ch;                                  // Variable into which we'll read each char.
  int cursorPosition;                       // Position in inputLine for current char.
  FILE *dataFile;                           // The file.

  // Open the file.
  dataFile = fopen ("testfile", "r");

  // Initial value - first line will be "1".
  lineNumber = 0;

  // Initial position of cursor within inputLine array:
  cursorPosition = 0;

  // Get first character.
  ch = fgetc (dataFile);

  // Keep reading chars until EOF char is read.
  while (ch != EOF) {

    // If we haven't seen the end of a line, put char into current inputLine.
    if (ch != '\n') {

      // Of course, we have exceeded the space allotted.
      if (cursorPosition >= MAX_CHARS_PER_LINE) {
        // Can't append.
        printf ("Input line size exceeded - exiting program\n");
        exit (0);
      }

      // OK, there's space, so append to inputLine.
      inputLine[cursorPosition] = ch;
      cursorPosition ++;

    }
    else {

      // Need to place a string-terminator because that's not in the file.
      inputLine[cursorPosition] = '\0';

      // Print.
      lineNumber ++;
      printf ("Line %4d: %s\n", lineNumber, inputLine);

      // Reset cursor.
      cursorPosition = 0;

    }

    // Get next char.
    ch = fgetc (dataFile);

  } // end while


  // Done.
  fclose (dataFile);

}