Dart

Append Dir Tree to Existing Zip w/out Rewriting Entire Zip

See more Zip Examples

Demonstrates how to use the QuickAppend method to append a directory tree to an existing .zip archive. This method works by editing the existing .zip -- it does not rewrite or recompress the contents of the existing .zip. It is the fastest way to append additional files to a pre-existing large .zip archive. Dart

import 'package:chilkat/chilkat.dart';

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

  final zip = CkZip();

  // The NewZip method only initializes the Zip object -- it does
  // not create or write a .zip file.
  try {
    zip.newZip('notUsed.zip');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Add a references to all files in a directory tree.
  // Note: this does not read or compress the file contents --
  // it simply adds file references to the zip object.
  final recurse = true;
  try {
    zip.appendFiles('c:/temp/abc123/*', recurse);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Appends the contents of the zip object to the preExisting.zip
  // zip archive.  preExisting.zip is opened, and the files
  // referenced by this zip object are streamed in, compressed,
  // and appended to the end of the archive.
  try {
    zip.quickAppend('preExisting.zip');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Success!');

  // Note: Additional files, directory trees, or in-memory data
  // can be appended by calling AddFile, AppendFiles,
  // AddString, AddBd, AddSb, etc. multiple times.
  // Whatever files and/or in-memory data that are referenced by
  // this zip object will be appended to preExisting.zip when
  // QuickAppend is called.
}