isatty            173 libavutil/log.c         use_color = (term && isatty(2));
isatty            371 libavutil/log.c         is_atty = isatty(2) ? 1 : -1;
isatty            397 tests/checkasm/checkasm.c         use_color = term && strcmp(term, "dumb") && isatty(2);