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C

MIME -- Convert Base64 to Binary

See more MIME Examples

Loads MIME containing a base64 body and converts it to binary. This changes the Content-Transfer-Encoding header to "binary", and the body is stored as raw unencoded bytes.

The MIME file initially loaded in this example contains:

Content-Disposition: attachment; filename="starfish20.jpg"
Content-Type: image/jpeg; name="starfish20.jpg"
Content-Transfer-Encoding: base64
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==

After converting, the binary MIME looks like the following. (Note: Loading it into a text editor and saving it will corrupt the binary data by dropping bytes. Non-text binary data CANNOT be handled as if it were text without corruption.)

Chilkat C Downloads

C
#include <C_CkMime.h>
#include <C_CkByteData.h>
#include <C_CkFileAccess.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkMime mime;
    const char *mimeStr;
    HCkByteData mimeBytes;
    HCkFileAccess fac;

    success = FALSE;

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

    mime = CkMime_Create();

    success = CkMime_LoadMimeFile(mime,"qa_data/mime/starfish20_base64.mim");
    if (success != TRUE) {
        printf("%s\n",CkMime_lastErrorText(mime));
        CkMime_Dispose(mime);
        return;
    }

    //  Show the MIME.  We can see the body is base64 encoded.
    mimeStr = CkMime_getMime(mime);
    printf("%s\n",mimeStr);

    //  Change the Content-Transfer-Encoding to "binary"
    CkMime_SetHeaderField(mime,"Content-Transfer-Encoding","binary");

    //  Note: Now that the MIME's body is binary (JPG image data),
    //  we CANNOT get the MIME as a string.  We can only get it as bytes.

    mimeBytes = CkByteData_Create();
    success = CkMime_GetMimeBytes(mime,mimeBytes);

    //  We can save it to a file, and then examine it..
    fac = CkFileAccess_Create();
    success = CkFileAccess_WriteEntireFile(fac,"qa_data/mime/starfish20_binary.mim",mimeBytes);
    if (success != TRUE) {
        printf("%s\n",CkFileAccess_lastErrorText(fac));
    }
    else {
        printf("Saved binary MIME.\n");
    }



    CkMime_Dispose(mime);
    CkByteData_Dispose(mimeBytes);
    CkFileAccess_Dispose(fac);

    }