Node.js

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

See more Zip Examples

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

Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

    var zip = new chilkat.Zip();

    // Open an existing ZIP archive.
    success = zip.OpenZip("qa_data/zips/documents.zip");
    if (success == false) {
        console.log(zip.LastErrorText);
        return;
    }

    // Locate the PDF entry within the ZIP archive.
    var entry = new chilkat.ZipEntry();

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

    // ------------------------------------------------------------
    // Inflate the ZIP entry directly into a BinData object.
    // 
    // The uncompressed bytes are stored entirely in memory.
    // 
    var pdfData = new chilkat.BinData();

    success = entry.UnzipToBd(pdfData);
    if (success == false) {
        console.log(entry.LastErrorText);
        return;
    }

    console.log("Uncompressed size = " + pdfData.NumBytes);
    console.log("");

    // ------------------------------------------------------------
    // Optionally save the uncompressed bytes to a file.
    // 
    success = pdfData.WriteFile("qa_output/report.pdf");
    if (success == false) {
        console.log(pdfData.LastErrorText);
        return;
    }

    zip.CloseZip();

    console.log("PDF extracted successfully.");

}

chilkatExample();