Http请求: Winsock

Question

在编写http请求时，我使用Visual作为c++，现在我的代码是这样的，

#define WIN32_LEAN_AND_MEAN

#include "stdafx.h"
#include <cstdio>
#include <cstdlib>
#include <Winsock2.h>
#include <WS2tcpip.h>
#include <windows.h>

#pragma comment (lib,"ws2_32")

int _tmain(int argc, _TCHAR* argv[])
    {
      WSADATA wsaData;
      int iResult = WSAStartup(MAKEWORD(2,2),&wsaData);
      SOCKET m_socket;
      m_socket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
      if(m_socket==INVALID_SOCKET)
        {
        printf("Invalid Socket :WSAGetLastError()");
            }
    sockaddr_in clientService;
    clientService.sin_family = AF_INET;
    clientService.sin_addr.s_addr = inet_addr("127.0.0.1");
    clientService.sin_port = htons(5357);
    LPHOSTENT host = gethostbyname("72.144.89.32");

    if(connect(m_socket,(SOCKADDR*)&clientService,sizeof(clientService))==SOCKET_ERROR)
    {
      printf("Connection Failure");
      WSACleanup();
      return 1;
    }

    char buffer[2048];

    strcpy(buffer,"POST /dbarea.php HTTP/1.1\n");
    strcat(buffer,"Content - Type:application/x-www-form-urlencoded\n");
    strcat(buffer,"Host: localost\n");
    strcat(buffer,"content-Length:32\n");
    strcat(buffer,"\n");
    strcat(buffer,"username=emeka1&password=laikan112");
    //int n = write(SOCKADDR*,buffer,strlen(buffer));

    printf("Data Sent Successfully..");

    return 0;

        }

现在我的php是这样的

<?php
session_start();
$username = urldecode($_POST['username']);
$password = urldecode($_POST['password']);

echo "Username: $username\nPassword:$password";
?>

现在我有一个关于php区域的问题，它没有接收信息并再次打印出来，让我们看看，可能会有什么问题呢？

Answer 1

HTTP请求中有几个错误。

1. 您需要使用\r\n而不是\n。
2. Content - Type需要成为Content-Type。
3. localost需要成为localhost。
4. content-Length:32需要是Content-Length: 34

试试这个：

int _tmain(int argc, _TCHAR* argv[])
{
    WSADATA wsaData;
    int iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
    if (iResult != 0)
    {
        printf("WinSock startup error: %d\n", iResult);
        return 1;
    }

    SOCKET m_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (m_socket == INVALID_SOCKET)
    {
        printf("Socket creation error: %d\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    sockaddr_in clientService = {0};
    clientService.sin_family = AF_INET;
    clientService.sin_addr.s_addr = inet_addr("127.0.0.1");
    clientService.sin_port = htons(5357);

    if (connect(m_socket, (SOCKADDR*)&clientService, sizeof(clientService)) == SOCKET_ERROR)
    {
        printf("Connection error: %d\n", WSAGetLastError());
        closesocket(m_socket);
        WSACleanup();
        return 1;
    }

    char buffer[2048];

    strcpy(buffer, "POST /dbarea.php HTTP/1.1\r\n");
    strcat(buffer, "Content-Type: application/x-www-form-urlencoded\r\n");
    strcat(buffer, "Host: localhost:5357\r\n");
    strcat(buffer, "Content-Length: 34\r\n");
    strcat(buffer, "\r\n");
    strcat(buffer, "username=emeka1&password=laikan112");

    char ptr = buffer;
    int len = strlen(buffer);

    do
    {
        int n = send(m_socket, ptr, len, 0);
        if (n < 1)
        {
            if (n == SOCKET_ERROR)
                printf("Send error: %d\n", WSAGetLastError());
            else
                printf("disconnected by server\n");

            closesocket(m_socket);
            WSACleanup();
            return 1;
        }

        ptr += n;
        len -= n;
    }
    while (len > 0);

    printf("Data Sent Successfully..\n");

    closesocket(m_socket);
    WSACleanup();

    return 0;
}

如果有更好的替代方案，比如微软的WinInet/WinHTTP、curl库等，您真的不应该像这样从头开始编写自己的HTTP代码，让他们为您做艰苦的工作。

#include <WinInet.h>
#include <tchar.h>

void ReportWinInetError(const char *operation)
{
    DWORD dwErr = GetLastError();
    if (dwErr == ERROR_INTERNET_EXTENDED_ERROR)
    {
        LPTSTR szBuffer = NULL;
        DWORD dwLength = 0;

        BOOL bRet = InternetGetLastResponseInfo(&dwErr, NULL, &dwLength);
        if ((bRet == FALSE) && (GetLastError() == ERROR_INSUFFICIENT_BUFFER))
        {
            szBuffer = new TCHAR[dwLength+1];
            bRet = InternetGetLastResponseInfo(&dwErr, szBuffer, &dwLength);
        }

        if (bRet)
            _tprintf(_T("WinInet error while %hs: %u %*s"), operation, dwErr, dwLength, szBuffer);
        else
            printf("Unknown WinInet error while %s", operation);

        delete[] szBuffer;
    }
    else
        printf("WinInet error while %s: %u", operation, dwErr);
}

int _tmain(int argc, _TCHAR* argv[])
{
    HINTERNET hInternet = InternetOpen(TEXT("MyApp"), INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0);
    if (!hInternet)
    {
        ReportWinInetError("opening session");
        return 1;
    }

    HINTERNET hConnect = InternetConnect(hInternet, TEXT("127.0.0.1"), 5357, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 0);
    if (!hConnect)
    {
        ReportWinInetError("connecting session");
        InternetCloseHandle(hInternet);
        return 1;
    }

    HINTERNET hRequest = HttpOpenRequest(hConnect, TEXT("POST"), TEXT("/dbarea.php"), TEXT("HTTP/1.1"), NULL, NULL, 0, 0);
    if (!hRequest)
    {
        ReportWinInetError("opening request");
        InternetCloseHandle(hConnect);
        InternetCloseHandle(hInternet);
        return 1;
    }

    if (!HttpSendRequest(hRequest, TEXT("Content-Type: application/x-www-form-urlencoded"), -1, "username=emeka1&password=laikan112", 34))
    {
        ReportWinInetError("sending request");
        InternetCloseHandle(hRequest);
        InternetCloseHandle(hConnect);
        InternetCloseHandle(hInternet);
        return 1;
    }

    printf("Data Sent Successfully..\n");

    InternetCloseHandle(hRequest);
    InternetCloseHandle(hConnect);
    InternetCloseHandle(hInternet);

    return 0;
}

​

#include <curl/curl.h> 

int _tmain(int argc, _TCHAR* argv[])
{
    CURLCode ret = curl_global_init(CURL_GLOBAL_DEFAULT);
    if (ret != CURLE_OK)
    {
        printf("Curl init error: %d\n", ret);
        return 1;
    }

    CURL *curl = curl_easy_init(); 
    if (!curl)
    {
        printf("Curl request creation error\n");
        curl_global_cleanup(); 
        return 1;
    }

    curl_easy_setopt(curl, CURLOPT_URL, "http://127.0.0.1:5357/dbarea.php"); 
    curl_easy_setopt(curl, CURLOPT_POST, 1); 
    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "username=emeka1&password=laikan112");
    curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, -1);

    ret = curl_easy_perform(curl); 
    if (ret != CURLE_OK)
    {
        printf("Curl send error: %d\n", ret);
        curl_easy_cleanup(curl); 
        curl_global_cleanup(); 
        return 1;
    }

    printf("Data Sent Successfully..\n");

    curl_easy_cleanup(curl); 
    curl_global_cleanup(); 
}