#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

#define INITIAL_BUFFER_SIZE 2

char *aoc_read_input(void) {
  int buffer_size = INITIAL_BUFFER_SIZE;
  char *input_buffer = malloc(buffer_size);
  int chars_read = read(STDIN_FILENO, input_buffer, buffer_size);
  char *buffer_position = &input_buffer[chars_read];

  while (chars_read == buffer_size) {
    buffer_size *= 2;
    input_buffer = realloc(input_buffer, buffer_size);
    buffer_position = &input_buffer[chars_read];
    chars_read += read(STDIN_FILENO, buffer_position, buffer_size / 2);
  }

  input_buffer[chars_read] = 0;
  return input_buffer;
}