How can I read a paragraph in via the terminal as a single string in C?

Question

I\'m writing a C program that should read in an essay from a user. The essay is divided into multiple paragraphs. I don\'t know how many lines or characters the essay will be,

Answer 1

Hmmm to "not waste space in memory",

then how about excessive calls of realloc()?

char *Read_Paragraph_i(void) {
  size_t size = 0;
  size_t i = 0;
  char *dest = NULL; 
  int ch;
  while ((ch = fgetc(stdin)) != EOF) {
    if (ch == '#') break;
    size++;
    char *new_ptr = realloc(dest, size);
    assert(new_ptr);
    dest = new_ptr;
    dest[i++] = ch;
  }
  size++;
  char *new_ptr = realloc(dest, size+);
  assert(new_ptr);
  dest = new_ptr;
  dest[i++] = '\0';
  return dest;
}

A more sane approach would double the allocation size every time more memory is need, temporally wasting memory and then a final "right-size" allocation.