通过串行端口发送wchar_t消息

Question

the problem that I have is that when sending a message L"Second line" to my application to read serial port I am receiving "S econd L ine", but at putty I do received "Second line" I think that is because wchar_t is coded in 16 bit so I have a 00 between every letter. But still don't know how I can fix this, I am new with all these things so it is kind of confusing.

I am not sure if I need to set my byte size to 16 in my application?

I want to send that LPCWSTR LogpszMessage, because I am sending some logs messages from an application. Which is another code, working here must work there.

putty configuration is to 8 bits and this is what I am sending;

#include "stdafx.h"

#include <windows.h>
#include <stdio.h>

typedef _Null_terminated_ CONST WCHAR *LPCWSTR, *PCWSTR;

int main()
{

    LPCWSTR LogpszMessage = L"Second line";
    char bytes_to_send[] = "test1 y test2";

    // Declare variables and structures
    HANDLE hSerial;
    DCB dcbSerialParams = { 0 };
    COMMTIMEOUTS timeouts = { 0 };

    // Open the highest available serial port number
    fprintf(stderr, "Opening serial port...");
    hSerial = CreateFile(
        L"\\\\.\\COM24", GENERIC_READ | GENERIC_WRITE, 0, NULL,
        OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (hSerial == INVALID_HANDLE_VALUE)
    {
        fprintf(stderr, "Error\n");
        return 1;
    }
    else fprintf(stderr, "OK\n");

    dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
    if (GetCommState(hSerial, &dcbSerialParams) == 0)
    {
        fprintf(stderr, "Error getting device state\n");
        CloseHandle(hSerial);
        return 1;
    }

    dcbSerialParams.BaudRate = CBR_115200;
    dcbSerialParams.ByteSize = 8;
    dcbSerialParams.StopBits = ONESTOPBIT;
    dcbSerialParams.Parity = NOPARITY;
    if (SetCommState(hSerial, &dcbSerialParams) == 0)
    {
        fprintf(stderr, "Error setting device parameters\n");
        CloseHandle(hSerial);
        return 1;
    }

    // Set COM port timeout settings
    timeouts.ReadIntervalTimeout = 50;
    timeouts.ReadTotalTimeoutConstant = 50;
    timeouts.ReadTotalTimeoutMultiplier = 10;
    timeouts.WriteTotalTimeoutConstant = 50;
    timeouts.WriteTotalTimeoutMultiplier = 10;
    if (SetCommTimeouts(hSerial, &timeouts) == 0)
    {
        fprintf(stderr, "Error setting timeouts\n");
        CloseHandle(hSerial);
        return 1;
    }

    // Send specified text (remaining command line arguments)
    DWORD bytes_written, total_bytes_written = 0;
    fprintf(stderr, "Sending bytes...");
    /*if (!WriteFile(hSerial, bytes_to_send, sizeof(bytes_to_send), &bytes_written, NULL))
    {
        fprintf(stderr, "Error\n");
        CloseHandle(hSerial);
        return 1;
    }*/

    if (!WriteFile(hSerial, LogpszMessage, wcslen(LogpszMessage) * sizeof(wchar_t), &bytes_written, NULL))
    {
        fprintf(stderr, "Error\n");
        CloseHandle(hSerial);
        return 1;
    }
    fprintf(stderr, "%d bytes written\n", bytes_written);

    // Close serial port
    fprintf(stderr, "Closing serial port...");
    if (CloseHandle(hSerial) == 0)
    {
        fprintf(stderr, "Error\n");
        return 1;
    }
    fprintf(stderr, "OK\n");
    getchar();

    // exit normally
    return 0;
}

Thanks in advance.

Answer 1

I could not do it with WideCharToMultiByte(), yield me error when trying to use LPCWSTR LogpszMessage, so I did the job with wcstombs_s following microsoft documentation and it worked, now when reading the COM port there is no spaces caused by 00 of 16 bit characters.

Thank you Hans Passant !