Dart

Enable FTP MODE Z Compression

Demonstrates the Chilkat Ftp2.SetModeZ method, which enables MODE Z compression for subsequent data connections. It takes no arguments. Call it after connecting and only when the HasModeZ property is true.

Background: MODE Z compresses data on the fly (using zlib) as it crosses the wire, which can meaningfully speed up transfers of compressible content — text, HTML, logs — over a slow link. It is a server extension, so check HasModeZ first and expect it to be unavailable on many servers. There is little benefit for already-compressed data such as images or archives, where the CPU cost of compression buys almost nothing.

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Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Demonstrates the Ftp2.SetModeZ method, which enables MODE Z compression for subsequent data
  // connections.  It takes no arguments.  Call it after connecting, and only when the HasModeZ
  // property indicates the server supports it.

  final ftp = CkFtp2();

  ftp.hostname = 'ftp.example.com';
  ftp.username = 'myFtpLogin';

  // Normally you would not hard-code the password in source.  You should instead obtain it
  // from an interactive prompt, environment variable, or a secrets vault.
  ftp.password = 'myPassword';

  try {
    ftp.connect();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    ftp.changeRemoteDir('public_html');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Only enable compression if the server advertises MODE Z support.
  if (ftp.hasModeZ) {
    try {
      ftp.setModeZ();
    } on ChilkatException catch (e) {
      print(e.lastErrorText);
      return;
    }

    print('MODE Z compression enabled.');
  } else {
    print('The server does not support MODE Z.');
  }

  // Subsequent uploads, downloads, and listings are transferred compressed.

  try {
    ftp.disconnect();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }
}