find_linenum
off_t find_linenum(off_t);
linenum = find_linenum(pos);
linenum = find_linenum(pos);
(len = ch_length()) > 0 && find_linenum(len) != 0);
linenum = find_linenum(len - 1);
(linenum = find_linenum(len)) <= 0)
(last_linenum = find_linenum(len)) <= 0)
linenum = find_linenum(pos);
linenum = find_linenum(pos);
curtag->tag_linenum = find_linenum(linepos);