c++ - libserial readsome 返回奇怪的值（不是错误）

Question

我的操作系统：Ubuntu 14.04

IDE：Ecplipse Mars

库：GCC，libserial

我正在使用libserial通过串行总线进行通信。

#include <SerialStream.h>
#include <iostream>
#include <unistd.h>
#include <cstdlib>
#include <string.h>

/*****************************************************************************/
int main(int argc, char** argv)
{
    using namespace LibSerial ;
    SerialStream serial_port ;
    serial_port.Open("/dev/ttyACM0") ;

    if ( ! serial_port.good() )
    {
        std::cerr << "[" << __FILE__ << ":" << __LINE__ << "] "
                  << "Error: Could not open serial port."
                  << std::endl ;
        exit(1) ;
    }

    serial_port.SetBaudRate( SerialStreamBuf::BAUD_115200 ) ;
    if ( ! serial_port.good() )
    {
        std::cerr << "Error: Could not set the baud rate." << std::endl ;
        exit(1) ;
    }

    serial_port.SetCharSize( SerialStreamBuf::CHAR_SIZE_8 ) ;
    if ( ! serial_port.good() )
    {
        std::cerr << "Error: Could not set the character size." << std::endl ;
        exit(1) ;
    }

    serial_port.SetParity( SerialStreamBuf::PARITY_NONE ) ;
    if ( ! serial_port.good() )
    {
        std::cerr << "Error: Could not disable the parity." << std::endl ;
        exit(1) ;
    }

    serial_port.SetNumOfStopBits( 1 ) ;
    if ( ! serial_port.good() )
    {
        std::cerr << "Error: Could not set the number of stop bits."
                  << std::endl ;
        exit(1) ;
    }

    serial_port.SetFlowControl( SerialStreamBuf::FLOW_CONTROL_NONE ) ;
    if ( ! serial_port.good() )
    {
        std::cerr << "Error: Could not use hardware flow control."
                  << std::endl ;
        exit(1) ;
    }

    while(run)
    {
        int inCount = serial_port.rdbuf()->in_avail();
        if (inCount > 0)
        {
            char buffer[1024];
             // here is the problem     
            int nbytes = serial_port.readsome(buffer, inCount);
            if (!serial_port.good())
            {
                std::cerr << "Error: readsome";
            }

            serial_port.write(buffer, strlen(buffer));
            std::cerr << "read: " << nbytes << "available: " << inCount << "\n";
        }
    }

    serial_port.Close();
    std::cerr << std::endl ;
    return EXIT_SUCCESS ;
}

重点

阅读（）

正确读取并填充缓冲区，但其返回值不如读取值的数量。它总是返回“6394433”。

知道这里出了什么问题吗？