Unicode C

Extract Embedded Files from PDF

Demonstrates how to get information about the embedded files (if any) contained within a PDF, and shows how to extract each file.

Note: This example requires Chilkat v9.5.0.95 or greater.

Unicode C

#include <C_CkPdfW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkBinDataW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPdfW pdf;
    int numFiles;
    HCkJsonObjectW json;
    HCkBinDataW bd;
    int i;
    const wchar_t *filename;

    success = FALSE;

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

    pdf = CkPdfW_Create();

    success = CkPdfW_LoadFile(pdf,L"qa_data/pdf/embedded_files/my_embedded_files_test.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        return;
    }

    //  Note: The embedded file functionality was added in Chilkat v9.5.0.95

    //  How many embedded files exist within the opened PDF?
    numFiles = CkPdfW_getNumEmbeddedFiles(pdf);
    wprintf(L"Number of embedded files: %d\n",numFiles);

    json = CkJsonObjectW_Create();
    CkJsonObjectW_putEmitCompact(json,FALSE);

    bd = CkBinDataW_Create();

    //  Get information about each file, and extract each to the filesystem.
    i = 0;
    while (i < numFiles) {

        success = CkPdfW_GetEmbeddedFileInfo(pdf,i,json);
        if (success == FALSE) {
            wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
            CkPdfW_Dispose(pdf);
            CkJsonObjectW_Dispose(json);
            CkBinDataW_Dispose(bd);
            return;
        }

        wprintf(L"%s\n",CkJsonObjectW_emit(json));

        //  Get the filename from the JSON.
        filename = L"someFile.dat";

        //  The filename SHOULD always be present..
        if (CkJsonObjectW_HasMember(json,L"filename") == TRUE) {
            filename = CkJsonObjectW_stringOf(json,L"filename");
        }

        //  Get the file data.
        success = CkPdfW_GetEmbeddedFileBd(pdf,i,bd);
        if (success == FALSE) {
            wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
            CkPdfW_Dispose(pdf);
            CkJsonObjectW_Dispose(json);
            CkBinDataW_Dispose(bd);
            return;
        }

        //  Save the contents of the bd to the filename (in the current working directory) in the filesystem.
        success = CkBinDataW_WriteFile(bd,filename);
        if (success == FALSE) {
            wprintf(L"Failed to write output file.\n");
        }

        i = i + 1;
    }

    //  Sample output for the above code:

    //  Number of embedded files: 3
    //  {
    //    "filename": "employees.json",
    //    "desc": "JSON",
    //    "subType": "application/json",
    //    "size": 159,
    //    "creationDate": "D:20230715170506-05'00'",
    //    "modDate": "D:20160207153838-05'00'"
    //  }
    //  
    //  {
    //    "filename": "rsaPubKey.pem",
    //    "desc": "RSA Public Key PEM",
    //    "size": 451,
    //    "creationDate": "D:20230715170546-05'00'",
    //    "modDate": "D:20150724133153-05'00'"
    //  }
    //  
    //  {
    //    "filename": "starfish.jpg",
    //    "desc": "Starfish JPG",
    //    "subType": "image/jpeg",
    //    "size": 6229,
    //    "creationDate": "D:20230715170356-05'00'",
    //    "modDate": "D:20080529103055-05'00'"
    //  }


    CkPdfW_Dispose(pdf);
    CkJsonObjectW_Dispose(json);
    CkBinDataW_Dispose(bd);

    }