// file: lecture_14/example.cc
//
// a simple program to play around with data types, including
// pointers and arrays
//

// system include files
//
#include "example.h"

// function: main
//
// main program starts here
//
int main(int argc, char** argv) {

  // declare a character string
  //
  /*
  char joe[] = "Joe";

  // declare some other arrays
  //
  float sig[] = {1.0, 2.0, 3.0};
  short int ssig[] = {27, 99, 39};

  short int* ptr = ssig;
  fprintf(stdout, "sig = %u\n", ssig);
  fprintf(stdout, "the value at memory location (%u) = %d\n", ssig, *ptr);

  float* fptr = (float*)(void*)ssig;
  fprintf(stdout, "the value at memory location (%u) = %f\n", ssig, *fptr);
  
  // open a file
  //
  FILE* fp = fopen(argv[1], "r");
  if (fp == (FILE*)NULL) {
    fprintf(stderr, "[%s] Ouch - an error has occurred\n", argv[0]);
    return -1;
  }

  // allocate space to hold each line
  //
  char buf[MAX_LINE_LENGTH];

  // count the number of lines
  //
  long num_lines = 0;
  while (fgets(buf, MAX_LINE_LENGTH, fp)) {
    num_lines++;
  }
  fprintf(stdout, "the number of lines in %s is %d\n", argv[1], num_lines);

  // we must rewind the file
  //
  rewind(fp);

  // size the lines array to only what I need
  //
  char* lines[num_lines];

  // loop over the file
  //
  num_lines = 0;
  while (fgets(buf, MAX_LINE_LENGTH, fp)) {

    // copy the line to lines[]
    //
    lines[num_lines] = new char[strlen(buf) + 1];
    //    lines[num_lines] = (char*)malloc(strlen(buf) + 1);
    strcpy(lines[num_lines], buf);
    num_lines++;
  }

  fprintf(stdout, "number of lines read = %d\n", num_lines);
  for (long i = 0; i < num_lines; i++) {
    fprintf(stdout, "[%d] %s", i, lines[i]);
  }

  // clean up memory
  //
  for (long i = 0; i < num_lines; i++) {
    delete [] lines[i];
  }

  // close file
  //
  fclose(fp);
*/
  
  // allocate more memory
  //
  char* pchr = new char[MAX_LINE_LENGTH];
  strcpy(pchr, "Today is a Friday after an exam.");
  fprintf(stdout, "pchar: %s\n", pchr);
  fprintf(stdout, "pchar+1: %s\n", pchr + 1);

  float* fptr = (float*)pchr;
  fprintf(stdout, "float value = %f\n", *fptr);

  /*
  char* str = pchr;
  long i = 0;
  while (*str != (char)NULL) {
    fprintf(stdout, "[%d] value = %c (%d)\n", i, *str, *str);
    i++;
    str++;
  }

  long N = 3;
  short int ssig[N] = {27, 99, 39};
  short int* ptr = ssig;
  i = 0;
  while (N > 0) {
    fprintf(stdout, "[%d] value = %d\n", i, *ptr);
    N--;
    i++;
  }
*/

  // exit gracefully
  //
  return(0);
}