Unicode C++

Get the Last-Modified Date Before HTTP Download

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

#include <CkHttpW.h>
#include <CkHttpResponseW.h>
#include <CkDateTimeW.h>
#include <CkDtObjW.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkHttpW http;

    CkHttpResponseW resp;
    success = http.HttpNoBody(L"HEAD",L"https://www.chilkatsoft.com/hamlet.xml",resp);
    if (success == false) {
        wprintf(L"%s\n",http.lastErrorText());
        return;
    }

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

    // 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.
    const wchar_t *lastModStr = resp.getHeaderField(L"Last-Modified");
    // If the header exists...
    if (resp.get_LastMethodSuccess() == true) {
        // Parse the RFC822 format date/time string
        CkDateTimeW ckdt;
        ckdt.SetFromRfc822(lastModStr);

        // If we want to access individual date/time parts (in the local timezone)
        CkDtObjW dt;
        ckdt.ToDtObj(true,dt);

        wprintf(L"day/month/year = %d/%d/%d\n",dt.get_Day(),dt.get_Month(),dt.get_Year());
    }
    }