static int perf_parse_file(config_fn_t fn, void *data)
{
	int comment = 0;
	int baselen = 0;
	static char var[MAXNAME];

	/* U+FEFF Byte Order Mark in UTF8 */
	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
	const unsigned char *bomptr = utf8_bom;

	for (;;) {
		int c = get_next_char();
		if (bomptr && *bomptr) {
			/* We are at the file beginning; skip UTF8-encoded BOM
			 * if present. Sane editors won't put this in on their
			 * own, but e.g. Windows Notepad will do it happily. */
			if ((unsigned char) c == *bomptr) {
				bomptr++;
				continue;
			} else {
				/* Do not tolerate partial BOM. */
				if (bomptr != utf8_bom)
					break;
				/* No BOM at file beginning. Cool. */
				bomptr = NULL;
			}
		}
		if (c == '\n') {
			if (config_file_eof)
				return 0;
			comment = 0;
			continue;
		}
		if (comment || isspace(c))
			continue;
		if (c == '#' || c == ';') {
			comment = 1;
			continue;
		}
		if (c == '[') {
			baselen = get_base_var(var);
			if (baselen <= 0)
				break;
			var[baselen++] = '.';
			var[baselen] = 0;
			continue;
		}
		if (!isalpha(c))
			break;
		var[baselen] = tolower(c);
		if (get_value(fn, data, var, baselen+1) < 0)
			break;
	}
	die("bad config file line %d in %s", config_linenr, config_file_name);
}

Unknown