C++

Fetch an IMAP Attachment into a BinData

Demonstrates the Chilkat Imap.FetchAttachmentBd method, which stores one attachment's bytes in a BinData object. The first argument is the Email, the second is the zero-based attachment index, and the third is the BinData, which is cleared before the operation. This example fetches the first attachment and prints its byte count.

Background: A BinData holds raw bytes, so it works for any attachment type — image, PDF, zip, and so on. From there you can save it, hash it, or hand it to another API expecting a byte buffer, all without touching the filesystem. Use the string/StringBuilder variants only when the attachment is known to be text.

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C++

#include <CkImap.h>
#include <CkEmail.h>
#include <CkBinData.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the Imap.FetchAttachmentBd method, which downloads one attachment's bytes into
    //  a BinData object.  The 1st argument is the Email, the 2nd is the zero-based attachment
    //  index, and the 3rd is the BinData (which is cleared first).
    //  
    //  The message is fetched headers-only, then the attachment is downloaded on demand.

    CkImap imap;

    imap.put_Ssl(true);
    imap.put_Port(993);

    success = imap.Connect("imap.example.com");
    if (success == false) {
        std::cout << imap.lastErrorText() << "\r\n";
        return;
    }

    success = imap.Login("user@example.com","myPassword");
    if (success == false) {
        std::cout << imap.lastErrorText() << "\r\n";
        return;
    }

    success = imap.SelectMailbox("Inbox");
    if (success == false) {
        std::cout << imap.lastErrorText() << "\r\n";
        return;
    }

    //  Fetch only the message headers.  Attachment bodies are NOT downloaded, but the ckx-imap-*
    //  metadata describing the attachments is present, so the attachment info methods still work.
    bool headersOnly = true;
    bool useUid = false;
    int seqNum = 1;
    CkEmail email;
    success = imap.FetchEmail(headersOnly,seqNum,useUid,email);
    if (success == false) {
        std::cout << imap.lastErrorText() << "\r\n";
        return;
    }

    int numAttach = imap.GetMailNumAttach(email);
    if (numAttach > 0) {
        //  Download just the first attachment's bytes from the server into a BinData.
        CkBinData bd;
        success = imap.FetchAttachmentBd(email,0,bd);
        if (success == false) {
            std::cout << imap.lastErrorText() << "\r\n";
            return;
        }

        std::cout << "Attachment size: " << bd.get_NumBytes() << " bytes" << "\r\n";
    }

    success = imap.Disconnect();
    if (success == false) {
        std::cout << imap.lastErrorText() << "\r\n";
        return;
    }
    }