#include <stdio.h>

void main()
{
  char buffer[256];
  FILE* read_f = fopen("./sample.txt", "r");
  FILE* write_f = stdout;

  int b = 0;

  // read the second half of the file by seeking to end
  // and rewinding to the midpoint.
  // fseek() does not return a position!
  //     fp     offset   base
  fseek(read_f,   0,   SEEK_END);
  b = ftell(read_f);
  fseek(read_f, (b/2),  SEEK_SET);

  do {
    b = fread(buffer, 1, 255, read_f);
    fwrite(buffer, 1, b, write_f);
  } while(!feof(read_f));

  // maybe need fflush(write_f);
  close(read_f);
}