2012/4/16 Nguyễn Thái Ngọc Duy [off-list ref]:

+int printf_ln(const char *fmt, ...)
+{
+       int ret;
+       va_list ap;
+       va_start(ap, fmt);
+       ret = vprintf(fmt, ap);
+       va_end(ap);
+       if (ret >= 0)
+               ret += printf("\n");

<snip>

+               ret += fprintf(fp, "\n");

Apart from Jonathan's comment, isn't [f]printf a big hammer for this?
Wouldn't putchar / fputc be a tad more light-weight (and perhaps
clearer)?