c语言ping程序代码

下面是一个简单的 C 语言 Ping 程序，可以用于在 Windows 系统下测试网络连接：

#include <stdio.h>
#include <winsock2.h>
#include <windows.h>
#include <iphlpapi.h>
#include <icmpapi.h>

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

int main(int argc, char *argv[]) {
    if (argc != 2) {
        printf("Usage: %s <host>\n", argv[0]);
        return 1;
    }

    const char* host = argv[1];
    if (strlen(host) > MAX_PATH) {
        printf("Host name is too long!\n");
        return 1;
    }

    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("WSAStartup failed!\n");
        return 1;
    }

    HANDLE icmpHandle = IcmpCreateFile();
    if (icmpHandle == INVALID_HANDLE_VALUE) {
        printf("IcmpCreateFile failed!\n");
        WSACleanup();
        return 1;
    }

    char sendBuf[32] = { 0 };
    DWORD dataSize = sizeof(sendBuf);

    DWORD ipAddr = inet_addr(host);
    if (ipAddr == INADDR_NONE) {
        struct hostent* hostEnt = gethostbyname(host);
        if (hostEnt == NULL || hostEnt->h_addrtype != AF_INET) {
            printf("Unknown host %s!\n", host);
            IcmpCloseHandle(icmpHandle);
            WSACleanup();
            return 1;
        }
        ipAddr = *(DWORD*)hostEnt->h_addr_list[0];
    }

    printf("Pinging %s [%s] with %d bytes of data:\n", host, inet_ntoa(*(in_addr*)&ipAddr), dataSize);

    for (int i = 0; i < 4; i++) {
        if (IcmpSendEcho(icmpHandle, ipAddr, sendBuf, dataSize, NULL, NULL, 1000) == 0) {
            printf("Request timed out.\n");
        } else {
            printf("Reply from %s: %d bytes in %ldms TTL=%d\n",
                inet_ntoa(*(in_addr*)&ipAddr), dataSize,
                ((PIP_ECHO_REPLY)sendBuf)->RoundTripTime,
                ((PIP_ECHO_REPLY)sendBuf)->Options.Ttl);
        }
        Sleep(1000);
    }

    IcmpCloseHandle(icmpHandle);
    WSACleanup();

    return 0;
}

这个程序使用了 WinSock 和 ICMP 协议，可以在 Windows 系统下运行。它会发送四个 ICMP 回显请求（即 Ping 请求），并等待每个请求的回复。如果在一定时间内没有收到回复，就认为该请求超时。如果收到回复，则打印回复报文的信息，包括源 IP 地址、数据长度、往返时间（即时延）和 TTL（生存时间）。