Method DoReadTo

util/stream/input.cpp:193–217

        }

        size_t DoReadTo(TString& st, char ch) override {
            auto&& guard = Guard(M_);

            (void)guard;

            const auto r = getdelim(&B_, &L_, ch, F_);

            if (r < 0) {
                if (ferror(F_)) {
                    ythrow TSystemError() << "can not read from stdin";
                }

                st.clear();

                return 0;
            }

            st.AssignNoAlias(B_, r);

            if (st && st.back() == ch) {
                st.pop_back();
            }

            return r;
        }

        TAdaptiveLock M_;
        char* B_ = nullptr;