您可以为bufio.Scanner编写自定义bufio.SplitFunc。例如：

// Mostly bufio.ScanLines code:
func ScanPDFLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
    if atEOF && len(data) == 0 {
        return 0, nil, nil
    }
    if i := bytes.IndexAny(data, "\r\n"); i >= 0 {
        if data[i] == '\n' {
            // We have a line terminated by single newline.
            return i + 1, data[0:i], nil
        }
        advance = i + 1
        if len(data) > i+1 && data[i+1] == '\n' {
            advance += 1
        }
        return advance, data[0:i], nil
    }
    // If we're at EOF, we have a final, non-terminated line. Return it.
    if atEOF {
        return len(data), data, nil
    }
    // Request more data.
    return 0, nil, nil
}

像这样使用它：

scan := bufio.NewScanner(r)
scan.Split(ScanPDFLines)

当我阅读一个旧的Mac生成的文件，只有CR行结束时，我遇到了一个边缘情况，如果CRLF被分割到缓冲区边界，可接受的答案会将它们视为单独的行结束符。如果缓冲区以CR结尾，你基本上需要提前退出并请求更多的数据。

func scanLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
    if atEOF && len(data) == 0 {
        return 0, nil, nil
    }
    if i := bytes.IndexAny(data, "\r\n"); i >= 0 {
        if data[i] == '\n' {
            // We have a line terminated by single newline.
            return i + 1, data[0:i], nil
        }
        // We have a line terminated by carriage return at the end of the buffer.
        if !atEOF && len(data) == i+1 {
            return 0, nil, nil
        }
        advance = i + 1
        if len(data) > i+1 && data[i+1] == '\n' {
            advance += 1
        }
        return advance, data[0:i], nil
    }
    // If we're at EOF, we have a final, non-terminated line. Return it.
    if atEOF {
        return len(data), data, nil
    }
    // Request more data.
    return 0, nil, nil
}