(Delphi DLL) Unzip Files Matching a Pattern (such as *.xml)

Example code to unzip Files Matching a Pattern (such as *.xml)

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Zip, Http;

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: HCkHttp;
success: Boolean;
zip: HCkZip;
zipContentsXml: PWideChar;
count: Integer;

begin
// This example works with the .zip located at http://www.example-code.com/data/test.zip

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// First, let's download the .zip
http := CkHttp_Create();
success := CkHttp_Download(http,'http://www.example-code.com/data/test.zip','qa_test/test.zip');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

zip := CkZip_Create();

success := CkZip_OpenZip(zip,'qa_test/test.zip');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;

// Show what's in the .zip by getting the directory as XML.
zipContentsXml := CkZip__getDirectoryAsXML(zip);
if (CkZip_getLastMethodSuccess(zip) <> True) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;

Memo1.Lines.Add(zipContentsXml);

// In this case, the contents of our .zip look like this:
// <?xml version="1.0" encoding="utf-8" ?>
// <zip_contents>
//     <dir name="test">
//         <dir name="abc">
//             <dir name="123">
//                 <file>ecc_public.pem</file>
//                 <file>starfish.jpg</file>
//             </dir>
//             <file>comodo-certificates.pem</file>
//             <file>pigs.xml</file>
//         </dir>
//         <file>COMODORSACertificationAuthority.crt</file>
//         <file>hamlet.xml</file>
//     </dir>
// </zip_contents>

// ------------------------------------------------------------------------
// If we wish to unzip only .xml files, use "*.xml" for the pattern\
// Unzip to the "qa_output" directory relative to our current working directory.
// (You may unzip to an absolute path by passing an absolute path, such as "/someDir" or
// "C:/someDir", etc.)
// This will unzip only the .xml files.  The relative directory structure within
// the .zip will be created in the local filesystem under the unzip directory
// path passed in the first argument, which in this case is "qa_output".
count := CkZip_UnzipMatching(zip,'qa_output','*.xml',True);
if (count < 0) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;
Memo1.Lines.Add('unzipped ' + IntToStr(count) + ' matching file(s).');

// ------------------------------------------------------------------------
// If we wish to unzip only files under the "123" directory, we can do this:
count := CkZip_UnzipMatching(zip,'qa_output2','*/123/*',True);
if (count < 0) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;
Memo1.Lines.Add('unzipped ' + IntToStr(count) + ' matching file(s).');

// ------------------------------------------------------------------------
// If no asterisk character is used, then the match must be exact.
// For example, to unzip "test/hamlet.xml" we must pass the exact path
// as it is in the .zip.  We cannot just pass "hamlet.xml".
count := CkZip_UnzipMatching(zip,'qa_output3','test/hamlet.xml',True);
if (count < 0) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;
Memo1.Lines.Add('unzipped ' + IntToStr(count) + ' matching file(s).');

// ------------------------------------------------------------------------
// If we want to unzip any file named "hamlet.xml" found in any sub-directory...
count := CkZip_UnzipMatching(zip,'qa_output4','*/hamlet.xml',True);
if (count < 0) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;
Memo1.Lines.Add('unzipped ' + IntToStr(count) + ' matching file(s).');

CkHttp_Dispose(http);
CkZip_Dispose(zip);

end;