#define ANSI
#define WIN32_LEAN_AND_MEAN
#define _WIN32_WINNT   0x0501

#include <windows.h>
#include <winuser.h>
#include <Dbt.h>

#include <string>
#include <iostream>
#include <stdexcept>

#define HID_CLASSGUID {0x4d1e55b2, 0xf16f, 0x11cf,{ 0x88, 0xcb, 0x00, 0x11, 0x11, 0x00, 0x00, 0x30}}
#define CLS_NAME "DUMMY_CLASS"
#define HWND_MESSAGE     ((HWND)-3)

LRESULT message_handler(HWND__* hwnd, UINT uint, WPARAM wparam, LPARAM lparam)
{
    switch (uint)
    {
    case WM_NCCREATE: // before window creation
        return true;
        break;

    case WM_CREATE: // the actual creation of the window
    {
        // you can get your creation params here..like GUID..
        LPCREATESTRUCT params = (LPCREATESTRUCT) lparam;
        GUID InterfaceClassGuid = *((GUID*)params->lpCreateParams);
        DEV_BROADCAST_DEVICEINTERFACE NotificationFilter;
        ZeroMemory(&NotificationFilter, sizeof(NotificationFilter));
        NotificationFilter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
        NotificationFilter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
        NotificationFilter.dbcc_classguid = InterfaceClassGuid;
        HDEVNOTIFY dev_notify = RegisterDeviceNotification(hwnd, &NotificationFilter,
                                                           DEVICE_NOTIFY_WINDOW_HANDLE);
        if(dev_notify == NULL)
        {
            throw std::runtime_error("Could not register for devicenotifications!");
        }
        break;
    }

    case WM_DEVICECHANGE:
    {
        PDEV_BROADCAST_HDR lpdb = (PDEV_BROADCAST_HDR) lparam;
        PDEV_BROADCAST_DEVICEINTERFACE lpdbv = (PDEV_BROADCAST_DEVICEINTERFACE) lpdb;
        std::string path;
        if (lpdb->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE)
        {
            path = std::string(lpdbv->dbcc_name);
            switch (wparam)
            {
            case DBT_DEVICEARRIVAL:
                std::cout << "new device connected: " << path << "\n";
                break;

            case DBT_DEVICEREMOVECOMPLETE:
                std::cout << "device disconnected: " << path << "\n";
                break;
            }
        }
        break;
    }

    }
    return 0L;
}

int main(int argc, char* argv[])
{
    HWND hWnd = NULL;
    WNDCLASSEX wx;
    ZeroMemory(&wx, sizeof(wx));

    wx.cbSize = sizeof(WNDCLASSEX);
    wx.lpfnWndProc = reinterpret_cast<WNDPROC>(message_handler);
    wx.hInstance = reinterpret_cast<HINSTANCE>(GetModuleHandle(0));
    wx.style = CS_HREDRAW | CS_VREDRAW;
    wx.hInstance = GetModuleHandle(0);
    wx.hbrBackground = (HBRUSH)(COLOR_WINDOW);
    wx.lpszClassName = CLS_NAME;

    GUID guid = HID_CLASSGUID;

    if (RegisterClassEx(&wx))
    {
        hWnd = CreateWindow(CLS_NAME, "DevNotifWnd", WS_ICONIC,
                            0, 0, CW_USEDEFAULT, 0, HWND_MESSAGE,
                            NULL, GetModuleHandle(0), (void*)&guid);
    }

    if(hWnd == NULL)
    {
        throw std::runtime_error("Could not create message window!");
    }

    std::cout << "waiting for new devices..\n";

    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}

C Language online compiler

Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!

Read inputs from stdin

OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.

#include <stdio.h>
int main()
{
    char name[50];
    printf("Enter name:");
    scanf("%s", name);
    printf("Hello %s \n" , name );
    return 0;
    
}

About C

C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.

Key features:

  • Structured Programming
  • Popular system programming language
  • UNIX, MySQL and Oracle are completely written in C.
  • Supports variety of platforms
  • Efficient and also handle low-level activities.
  • As fast as assembly language and hence used as system development language.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition if-else is used.

if(conditional-expression) {
   // code
} else {
   // code
}

You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to if-else-if ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  // code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {  
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

One dimentional Array:

data-type array-name[size];

Two dimensional array:

data-type array-name[size][size];

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

Two types of functions are present in C

  1. Library Functions:

Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,

  1. User defined functions:

User defined functions are the ones which are written by the programmer based on the requirement.

How to declare a Function

return_type function_name(parameters);

How to call a Function

function_name (parameters)

How to define a Function

return_type function_name(parameters) {  
  //code
}