Unicode C++

Unzip a ZIP Entry Directly into a BinData Object Using ZipEntry.UnzipToBd

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This example demonstrates how to use the ZipEntry.UnzipToBd method to inflate a ZIP entry directly into a BinData object.

The entry contents are uncompressed entirely in memory without creating a file on disk.

This is useful when:

• Processing ZIP entry data entirely in memory
• Avoiding temporary filesystem files
• Working with binary files such as images, PDFs, or certificates
• Passing uncompressed ZIP data directly to other APIs

The example opens a ZIP archive, locates a PDF entry, inflates it into a BinData object, and then writes the uncompressed bytes to a new file.

Suppose the ZIP archive contains:

docs/report.pdf

The entry is uncompressed directly into memory before optionally being saved to:

qa_output/report.pdf

Unicode C++

#include <CkZipW.h>
#include <CkZipEntryW.h>
#include <CkBinDataW.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkZipW zip;

    //  Open an existing ZIP archive.
    success = zip.OpenZip(L"qa_data/zips/documents.zip");
    if (success == false) {
        wprintf(L"%s\n",zip.lastErrorText());
        return;
    }

    //  Locate the PDF entry within the ZIP archive.
    CkZipEntryW entry;

    success = zip.EntryOf(L"docs/report.pdf",entry);
    if (success == false) {
        wprintf(L"ZIP entry not found.\n");
        zip.CloseZip();
        return;
    }

    //  ------------------------------------------------------------
    //  Inflate the ZIP entry directly into a BinData object.
    //  
    //  The uncompressed bytes are stored entirely in memory.
    //  
    CkBinDataW pdfData;

    success = entry.UnzipToBd(pdfData);
    if (success == false) {
        wprintf(L"%s\n",entry.lastErrorText());
        return;
    }

    wprintf(L"Uncompressed size = %d\n",pdfData.get_NumBytes());
    wprintf(L"\n");

    //  ------------------------------------------------------------
    //  Optionally save the uncompressed bytes to a file.
    //  
    success = pdfData.WriteFile(L"qa_output/report.pdf");
    if (success == false) {
        wprintf(L"%s\n",pdfData.lastErrorText());
        return;
    }

    zip.CloseZip();

    wprintf(L"PDF extracted successfully.\n");
    }