System.IO.StreamReader.Peek C# (CSharp) Method

        public override int Peek()
        {
            if (_stream == null)
            {
                throw new ObjectDisposedException(null, SR.ObjectDisposed_ReaderClosed);
            }

            CheckAsyncTaskInProgress();

            if (_charPos == _charLen)
            {
                if (_isBlocked || ReadBuffer() == 0)
                {
                    return -1;
                }
            }
            return _charBuffer[_charPos];
        }

        private IEnumerable<Record> ReadRecords(string fileName)
        {
            var stringBuilder = new StringBuilder();

            using (var reader = new StreamReader(fileName))
            {
                ReadOnlyCollection<string> header;
                if (reader.Peek() >= 0)
                {
                    var first = this.ParseLine(reader.ReadLine(), stringBuilder).ToArray();

                    header = new ReadOnlyCollection<string>(first);
                }
                else
                {
                    yield break;
                }

                for (var i = 0; i < this._numberRecordsToSkip && reader.Peek() >= 0; i++)
                {
                    reader.ReadLine();
                }

                while (reader.Peek() >= 0)
                {
                    var items = this.ParseLine(reader.ReadLine(), stringBuilder).ToArray();

                    yield return new Record(header, items);
                }
            }
        }