text: #include <assert.h>
  #include <stdio.h>
  
  int main()
  {
      FILE *file = fopen("/sandbox/input.txt", "r");
      assert(file != NULL);
  
      char c = fgetc(file);
      while (c != EOF) {
          assert(fputc(c, stdout) != EOF);
          c = fgetc(file);
      }
  }
  