Listing serial ports on Windows - c++

Question

Header
#pragma once
#include <windows.h>
#include <iostream>
#include <stdlib.h>
#include <WinBase.h>
using namespace std;
class SerialPort {
public:
BOOL COM_exists(int port);
};
cpp
#include "stdafx.h"
#include <string.h>
#include "SerialPort.h"
using namespace std;
BOOL SerialPort::COM_exists(int port)
{
char buffer[7];
COMMCONFIG CommConfig;
DWORD size;
if (!(1 <= port && port <= 255))
{
return FALSE;
}
snprintf(buffer, sizeof buffer, "COM%d", port);
size = sizeof CommConfig;
// COM port exists if GetDefaultCommConfig returns TRUE
// or changes <size> to indicate COMMCONFIG buffer too small.
return (GetDefaultCommConfig(L"buffer", &CommConfig, &size)
|| size > sizeof CommConfig);
}
main
#include "stdafx.h"
#include <iostream>
#include "SerialPort.h"
using namespace std;
if(num==1)
{
int i;
for (i = 1; i < 256; ++i)
{
if (COM_exists(i))
{
cout <<"COM%d \n";
}
}
}
I want listing serial ports on Windows ,but I'm having a hard time.
Help me list the serial ports. error code = c3861 ,e0020
I want listing serial ports on windows.
The end of the road ,Select a serial port that can be connected to enable communication.
please help me

Answer 1

Main problem is here
if(num==1)
{
int i;
for (i = 1; i < 256; ++i)
{
if (COM_exists(i))
{
cout <<"COM%d \n";
}
}
}
In C++ code has to go in functions (a simplification but good enough for now) and the program starts with a special function called main. Also cout <<"COM%d \n"; is not the correct way to print a COM port, I've used the correct way in the code below. Also in the code above what is num supposed to be?
Anyway rewrite as follows and you're a little closer
int main() // start of program
{
int i;
for (i = 1; i < 256; ++i)
{
if (COM_exists(i))
{
cout << "COM " << i << "\n";
}
}
}
There are other problems such as the pointless SerialPort class. I would just remove that.
Replace
class SerialPort {
public:
BOOL COM_exists(int port);
};
with
BOOL COM_exists(int port);
and
BOOL SerialPort::COM_exists(int port)
with
BOOL COM_exists(int port)
The code looks like you are trying to learn C++ by cutting and pasting code from the internet. That is never going to work, C++ is a complex language and really needs formal study to be learned effectively. Here's a curated list of C++ books.