How do I get the disk drive serial number in C/C++

There are a few ways to do this. You could make calls using system to get the information.

For Linux:

system("hdparm -i /dev/hda | grep -i serial");

Without using system:

static struct hd_driveid hd;int fd;if ((fd = open("/dev/hda", O_RDONLY | O_NONBLOCK)) < 0) {    printf("ERROR opening /dev/hda\n");    exit(1);}if (!ioctl(fd, HDIO_GET_IDENTITY, &hd)) {    printf("%.20s\n", hd.serial_no);} else if (errno == -ENOMSG) {    printf("No serial number available\n");} else {    perror("ERROR: HDIO_GET_IDENTITY");    exit(1);}

For Windows:

system("wmic path win32_physicalmedia get SerialNumber");

Without using system (Based on Getting WMI Data ):

hres = pSvc->ExecQuery(    bstr_t("WQL"),    bstr_t("SELECT SerialNumber FROM Win32_PhysicalMedia"),    WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,     NULL,    &pEnumerator);hr = pclsObj->Get(L"SerialNumber", 0, &vtProp, 0, 0);

Here is a complete solution for Windows which wraps WMI calls without using cmd or system .
So you can easily get anything from WMI including hard drive serial number.

All you have to do is to call :

getWmiQueryResult(L"SELECT SerialNumber FROM Win32_PhysicalMedia", L"SerialNumber");

PS. It's based on official documentation and additionally does some better error handling and cleanup. Also you might want to use this or this for creating WQL queries.

#include "stdafx.h"#define _WIN32_DCOM#include <iostream>#include <comdef.h>#include <Wbemidl.h>#include <vector>#include <string>#pragma comment(lib, "wbemuuid.lib")enum class WmiQueryError {    None,    BadQueryFailure,    PropertyExtractionFailure,    ComInitializationFailure,    SecurityInitializationFailure,    IWbemLocatorFailure,    IWbemServiceConnectionFailure,    BlanketProxySetFailure,};struct WmiQueryResult{    std::vector<std::wstring> ResultList;    WmiQueryError Error = WmiQueryError::None;    std::wstring ErrorDescription;};WmiQueryResult getWmiQueryResult(std::wstring wmiQuery, std::wstring propNameOfResultObject, bool allowEmptyItems = false) {    WmiQueryResult retVal;    retVal.Error = WmiQueryError::None;    retVal.ErrorDescription = L"";    HRESULT hres;    IWbemLocator *pLoc = NULL;    IWbemServices *pSvc = NULL;    IEnumWbemClassObject* pEnumerator = NULL;    IWbemClassObject *pclsObj = NULL;    VARIANT vtProp;    // Step 1: --------------------------------------------------    // Initialize COM. ------------------------------------------    hres = CoInitializeEx(0, COINIT_MULTITHREADED);    if (FAILED(hres))    {        retVal.Error = WmiQueryError::ComInitializationFailure;        retVal.ErrorDescription = L"Failed to initialize COM library. Error code : " + std::to_wstring(hres);    }    else    {        // Step 2: --------------------------------------------------        // Set general COM security levels --------------------------        // note: JUCE Framework users should comment this call out,        // as this does not need to be initialized to run the query.        // see https://social.msdn.microsoft.com/Forums/en-US/48b5626a-0f0f-4321-aecd-17871c7fa283/unable-to-call-coinitializesecurity?forum=windowscompatibility         hres = CoInitializeSecurity(            NULL,            -1,                          // COM authentication            NULL,                        // Authentication services            NULL,                        // Reserved            RPC_C_AUTHN_LEVEL_DEFAULT,   // Default authentication             RPC_C_IMP_LEVEL_IMPERSONATE, // Default Impersonation              NULL,                        // Authentication info            EOAC_NONE,                   // Additional capabilities             NULL                         // Reserved        );        if (FAILED(hres))        {            retVal.Error = WmiQueryError::SecurityInitializationFailure;            retVal.ErrorDescription = L"Failed to initialize security. Error code : " + std::to_wstring(hres);        }        else        {            // Step 3: ---------------------------------------------------            // Obtain the initial locator to WMI -------------------------            pLoc = NULL;            hres = CoCreateInstance(                CLSID_WbemLocator,                0,                CLSCTX_INPROC_SERVER,                IID_IWbemLocator, (LPVOID *)&pLoc);            if (FAILED(hres))            {                retVal.Error = WmiQueryError::IWbemLocatorFailure;                retVal.ErrorDescription = L"Failed to create IWbemLocator object. Error code : " + std::to_wstring(hres);            }            else            {                // Step 4: -----------------------------------------------------                // Connect to WMI through the IWbemLocator::ConnectServer method                pSvc = NULL;                // Connect to the root\cimv2 namespace with                // the current user and obtain pointer pSvc                // to make IWbemServices calls.                hres = pLoc->ConnectServer(                    _bstr_t(L"ROOT\\CIMV2"), // Object path of WMI namespace                    NULL,                    // User name. NULL = current user                    NULL,                    // User password. NULL = current                    0,                       // Locale. NULL indicates current                    NULL,                    // Security flags.                    0,                       // Authority (for example, Kerberos)                    0,                       // Context object                     &pSvc                    // pointer to IWbemServices proxy                );                // Connected to ROOT\\CIMV2 WMI namespace                if (FAILED(hres))                {                    retVal.Error = WmiQueryError::IWbemServiceConnectionFailure;                    retVal.ErrorDescription = L"Could not connect to Wbem service.. Error code : " + std::to_wstring(hres);                }                else                {                    // Step 5: --------------------------------------------------                    // Set security levels on the proxy -------------------------                    hres = CoSetProxyBlanket(                        pSvc,                        // Indicates the proxy to set                        RPC_C_AUTHN_WINNT,           // RPC_C_AUTHN_xxx                        RPC_C_AUTHZ_NONE,            // RPC_C_AUTHZ_xxx                        NULL,                        // Server principal name                         RPC_C_AUTHN_LEVEL_CALL,      // RPC_C_AUTHN_LEVEL_xxx                         RPC_C_IMP_LEVEL_IMPERSONATE, // RPC_C_IMP_LEVEL_xxx                        NULL,                        // client identity                        EOAC_NONE                    // proxy capabilities                     );                    if (FAILED(hres))                    {                        retVal.Error = WmiQueryError::BlanketProxySetFailure;                        retVal.ErrorDescription = L"Could not set proxy blanket. Error code : " + std::to_wstring(hres);                    }                    else                    {                        // Step 6: --------------------------------------------------                        // Use the IWbemServices pointer to make requests of WMI ----                        // For example, get the name of the operating system                        pEnumerator = NULL;                        hres = pSvc->ExecQuery(                            bstr_t("WQL"),                            bstr_t(wmiQuery.c_str()),                            WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,                            NULL,                            &pEnumerator);                        if (FAILED(hres))                        {                            retVal.Error = WmiQueryError::BadQueryFailure;                            retVal.ErrorDescription = L"Bad query. Error code : " + std::to_wstring(hres);                        }                        else                        {                            // Step 7: -------------------------------------------------                            // Get the data from the query in step 6 -------------------                            pclsObj = NULL;                            ULONG uReturn = 0;                            while (pEnumerator)                            {                                HRESULT hr = pEnumerator->Next(WBEM_INFINITE, 1,                                    &pclsObj, &uReturn);                                if (0 == uReturn)                                {                                    break;                                }                                // VARIANT vtProp;                                // Get the value of desired property                                hr = pclsObj->Get(propNameOfResultObject.c_str(), 0, &vtProp, 0, 0);                                if (S_OK != hr) {                                    retVal.Error = WmiQueryError::PropertyExtractionFailure;                                    retVal.ErrorDescription = L"Couldn't extract property: " + propNameOfResultObject + L" from result of query. Error code : " + std::to_wstring(hr);                                }                                else {                                    BSTR val = vtProp.bstrVal;                                    // Sometimes val might be NULL even when result is S_OK                                    // Convert NULL to empty string (otherwise "std::wstring(val)" would throw exception)                                    if (NULL == val) {                                        if (allowEmptyItems) {                                            retVal.ResultList.push_back(std::wstring(L""));                                        }                                    }                                    else {                                        retVal.ResultList.push_back(std::wstring(val));                                    }                                }                            }                        }                    }                }            }        }    }    // Cleanup    // ========    VariantClear(&vtProp);    if (pclsObj)        pclsObj->Release();    if (pSvc)        pSvc->Release();    if (pLoc)        pLoc->Release();    if (pEnumerator)        pEnumerator->Release();    CoUninitialize();    return retVal;}void queryAndPrintResult(std::wstring query, std::wstring propNameOfResultObject){    WmiQueryResult res;    res = getWmiQueryResult(query, propNameOfResultObject);    if (res.Error != WmiQueryError::None) {        std::wcout << "Got this error while executing query: " << std::endl;        std::wcout << res.ErrorDescription << std::endl;        return; // Exitting function    }    for (const auto& item : res.ResultList) {        std::wcout << item << std::endl;    }}int main(int argc, char **argv){    // Get OS and partition    // queryAndPrintResult(L"SELECT * FROM Win32_OperatingSystem", L"Name");    // Get list of running processes    // queryAndPrintResult(L"Select * From Win32_Process", L"Name");    // Get serial number of Hard Drive    queryAndPrintResult(L"SELECT SerialNumber FROM Win32_PhysicalMedia", L"SerialNumber");    // Get id of CPU    queryAndPrintResult(L"SELECT ProcessorId FROM Win32_Processor", L"ProcessorId");    // Get desktops    queryAndPrintResult(L"SELECT * FROM Win32_DesktopMonitor ", L"DeviceId");    system("pause");}

Note:
@matkatmusic discovered that using this function on a background thread in the JUCE framework will fail if you try to CoInitializeSecurity. And suggests that by removing the CoInitializeSecurity() call, this function will correctly run the WMI query.

For Windows:wmic path win32_physicalmedia get SerialNumber

Here is example how to get back the data as a string running any command. we're using _popen instead of system suggested above

#include <cstdio>#include <iostream>#include <memory>#include <stdexcept>#include <string>#include <array>exec("wmic path win32_physicalmedia get SerialNumber");std::string exec(const char* cmd) {    std::array<char, 128> buffer;    std::string result;    std::shared_ptr<FILE> pipe(_popen(cmd, "r"), _pclose);    if (!pipe) throw std::runtime_error("_popen() failed!");    while (!feof(pipe.get())) {        if (fgets(buffer.data(), 128, pipe.get()) != NULL)            result += buffer.data();    }    return result;}