Strange behavior of stdout in C ++

Question

I want my program to display a unix windmill during processing. There is a for loop and at each iteration there is a printf function:

printf("Fetching articles (%c)\r",q);

q is one of the symbols of the windmill (- \ | /) depending on the iteration number.

Problem - it seems that in 100 iterations, there are only two changes in the displayed string, and each iteration takes about one second.

What could be for this?

Here's the whole cycle with two possible symbols for a windmill:

for (int i=0;i<numb_articles;i++) {
  memset(file_path,0x0,BUFF_SIZE);

  url=article_urls[i];

  if (rules->print!=NO_PRINT) {
    url=modify_url(url,rules->printout,rules->print);
    if (url=="NULL")
      continue;
  }

  get_page(url,file_content);

  if (strcmp(rules->save.data(),"NULL")!=0)
    if (!check_save(rules->save,file_content,url))
      continue;

  at_least_one_saved=true;
  numb_articles_accepted++;

  encoding_list[i]=get_encoding(file_content);

  title=get_title(file_content,err_msg);

  if (title=="")
    continue;

  title_list[i]=strdup(title.data());
  filename=get_filename(title);

  int count=numb_fn_found(filename_list,i,filename.data());
  char *tmp = new char[10];
  if (count>0) {
    sprintf(tmp,"(%d)",count);
    filename.insert((size_t)filename.length(),tmp);
  }

  filename_list[i]=strdup(filename.data());

  char q;
  if (i%2==0)
    q='|';
  else q='-';

  printf("Fetching articles (%c)\r",q);

  ofstream output_file;
  sprintf(file_path,TMP_FILE,filename.data());
  strncat(file_path,".html",5);
  output_file.open(file_path);

  output_file << file_content;

  output_file.close();
}

Answer 1

Reset after writing each line:

printf("Fetching articles (%c)\r",q);
fflush(stdout);

stdout .

Answer 2

() . , , . , fflush (stdout), .

Enjoy,

.