(Unicode C) Get the Last-Modified Date Before HTTP Download

Demonstrates how to send a HEAD request to get the last-modified date of a file on a web server (without downloading the file).

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#include <C_CkHttpW.h>
#include <C_CkHttpResponseW.h>
#include <C_CkDateTimeW.h>
#include <C_CkDtObjW.h>

void ChilkatSample(void)
    {
    HCkHttpW http;
    HCkHttpResponseW resp;
    const wchar_t *lastModStr;
    HCkDateTimeW ckdt;
    HCkDtObjW dt;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    http = CkHttpW_Create();

    resp = CkHttpW_GetHead(http,L"https://www.chilkatsoft.com/hamlet.xml");
    if (CkHttpW_getLastMethodSuccess(http) == FALSE) {
        wprintf(L"%s\n",CkHttpW_lastErrorText(http));
        CkHttpW_Dispose(http);
        return;
    }

    // Examine the response header.
    wprintf(L"%s\n",CkHttpResponseW_header(resp));

    // Here is a sample response header:

    // 	Content-Length: 279658
    // 	Content-Type: text/xml
    // 	Last-Modified: Thu, 12 May 2016 15:14:08 GMT
    // 	Accept-Ranges: bytes
    // 	ETag: "c1cd8bee60acd11:0"
    // 	Server: Microsoft-IIS/8.5
    // 	X-Powered-By: ASP.NET
    // 	X-Powered-By-Plesk: PleskWin
    // 	Date: Thu, 25 Jul 2019 16:40:54 GMT

    // Get the Last-Modified header.
    lastModStr = CkHttpResponseW_getHeaderField(resp,L"Last-Modified");
    // If the header exists...
    if (CkHttpResponseW_getLastMethodSuccess(resp) == TRUE) {
        // Parse the RFC822 format date/time string
        ckdt = CkDateTimeW_Create();
        CkDateTimeW_SetFromRfc822(ckdt,lastModStr);

        // If we want to access individual date/time parts (in the local timezone)
        dt = CkDateTimeW_GetDtObj(ckdt,TRUE);
        wprintf(L"day/month/year = %d/%d/%d\n",CkDtObjW_getDay(dt),CkDtObjW_getMonth(dt),CkDtObjW_getYear(dt));
        CkDtObjW_Dispose(dt);
    }

    CkHttpResponseW_Dispose(resp);


    CkHttpW_Dispose(http);
    CkDateTimeW_Dispose(ckdt);

    }