Objective-C

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

Objective-C

#import <CkoZip.h>
#import <CkoZipEntry.h>
#import <CkoBinData.h>

BOOL success = NO;

CkoZip *zip = [[CkoZip alloc] init];

//  Open an existing ZIP archive.
success = [zip OpenZip: @"qa_data/zips/documents.zip"];
if (success == NO) {
    NSLog(@"%@",zip.LastErrorText);
    return;
}

//  Locate the PDF entry within the ZIP archive.
CkoZipEntry *entry = [[CkoZipEntry alloc] init];

success = [zip EntryOf: @"docs/report.pdf" entry: entry];
if (success == NO) {
    NSLog(@"%@",@"ZIP entry not found.");
    [zip CloseZip];
    return;
}

//  ------------------------------------------------------------
//  Inflate the ZIP entry directly into a BinData object.
//  
//  The uncompressed bytes are stored entirely in memory.
//  
CkoBinData *pdfData = [[CkoBinData alloc] init];

success = [entry UnzipToBd: pdfData];
if (success == NO) {
    NSLog(@"%@",entry.LastErrorText);
    return;
}

NSLog(@"%@%d",@"Uncompressed size = ",[pdfData.NumBytes intValue]);
NSLog(@"%@",@"");

//  ------------------------------------------------------------
//  Optionally save the uncompressed bytes to a file.
//  
success = [pdfData WriteFile: @"qa_output/report.pdf"];
if (success == NO) {
    NSLog(@"%@",pdfData.LastErrorText);
    return;
}

[zip CloseZip];

NSLog(@"%@",@"PDF extracted successfully.");