用C++语言实现Ping命令

Ping命令可以用C++语言通过发送ICMP包来实现。以下是一个简单的实现：

#include <iostream>
#include <winsock2.h>
#include <iphlpapi.h>
#include <icmpapi.h>

#pragma comment(lib, "iphlpapi.lib")
#pragma comment(lib, "ws2_32.lib")

int main(int argc, char* argv[]) {
    WSADATA wsaData;
    int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != 0) {
        std::cout << "WSAStartup failed: " << iResult << std::endl;
        return 1;
    }

    if (argc < 2) {
        std::cout << "Usage: ping <hostname or IP address>" << std::endl;
        return 1;
    }

    std::string host = argv[1];

    HANDLE hIcmpFile = IcmpCreateFile();
    if (hIcmpFile == INVALID_HANDLE_VALUE) {
        std::cout << "IcmpCreateFile failed: " << GetLastError() << std::endl;
        WSACleanup();
        return 1;
    }

    char SendData[] = "Ping";
    LPVOID ReplyBuffer = malloc(sizeof(ICMP_ECHO_REPLY) + sizeof(SendData));
    if (ReplyBuffer == NULL) {
        std::cout << "malloc failed: " << GetLastError() << std::endl;
        IcmpCloseHandle(hIcmpFile);
        WSACleanup();
        return 1;
    }

    DWORD ReplySize = sizeof(ICMP_ECHO_REPLY) + sizeof(SendData);
    DWORD dwRetVal = IcmpSendEcho(hIcmpFile, inet_addr(host.c_str()), SendData, sizeof(SendData), NULL, ReplyBuffer, ReplySize, 1000);
    if (dwRetVal != 0) {
        PICMP_ECHO_REPLY pEchoReply = (PICMP_ECHO_REPLY)ReplyBuffer;
        std::cout << "Ping " << host << " successful: " << "Reply from " << inet_ntoa(pEchoReply->Address) << " time=" << pEchoReply->RoundTripTime << "ms" << std::endl;
    }
    else {
        std::cout << "Ping " << host << " failed: " << GetLastError() << std::endl;
    }

    free(ReplyBuffer);
    IcmpCloseHandle(hIcmpFile);
    WSACleanup();
    return 0;
}

运行程序时，通过命令行参数传入要ping的主机名或IP地址。程序将发送一个ICMP包到目标主机，并等待回复。如果收到回复，程序输出回复信息，否则输出错误信息。注意，该程序仅在Windows环境下可用。在Linux环境下，可以使用类似于该程序的套接字编程方法来实现Ping命令。