Lazarus Pascal Requires Chilkat v11.7.0+

Search a PDF with a Regular Expression

See more PDF Text Extraction Examples

Demonstrates searching a PDF with a regular expression (regex: true), limiting the number of results (maxResults), and matching whole words only (wholeWord). Lazarus Pascal

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Pdf,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  pdf: TPdf;
  json: TJsonObject;
  jsonOut: TJsonObject;
  i: Integer;
  count_i: Integer;

begin
  success := False;

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

  //  The PDF used in this example is available at order_records.pdf

  pdf := TPdf.Create;
  success := pdf.LoadFile('qa_data/pdf/order_records.pdf');
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  json := TJsonObject.Create;
  jsonOut := TJsonObject.Create;

  //  Find every order number.  With regex set to true, the query is a regular expression.
  json.UpdateString('query','ORD-[0-9]{4}-[0-9]{4}');
  json.UpdateBool('regex',True);
  //  We only want the matched text, so no context is needed.
  json.UpdateInt('context',0);

  success := pdf.ExtractText('search',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  WriteLn('Order numbers found: ' + jsonOut.IntOf('count'));
  i := 0;
  count_i := jsonOut.SizeOfArray('matches');
  while i < count_i do
    begin
      jsonOut.I := i;
      WriteLn(jsonOut.StringOf('matches[i].text'));
      i := i + 1;
    end;

  //  Find the e-mail addresses, but stop after the first three.
  json.UpdateString('query','[a-z0-9._]+@[a-z]+[.][a-z]+');
  json.UpdateInt('maxResults',3);
  success := pdf.ExtractText('search',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  WriteLn('First three e-mail addresses:');
  i := 0;
  count_i := jsonOut.SizeOfArray('matches');
  while i < count_i do
    begin
      jsonOut.I := i;
      WriteLn(jsonOut.StringOf('matches[i].text'));
      i := i + 1;
    end;

  //  wholeWord: true matches only whole words.  The word "cat" appears once in the PDF,
  //  but it is also inside "catalog" and "category".
  json.Delete('maxResults');
  json.UpdateBool('regex',False);
  json.UpdateString('query','cat');
  success := pdf.ExtractText('search',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('Occurrences of cat (any): ' + jsonOut.IntOf('count'));

  json.UpdateBool('wholeWord',True);
  success := pdf.ExtractText('search',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('Occurrences of cat (whole word): ' + jsonOut.IntOf('count'));

  //  Sample output:

  //  Order numbers found: 9
  //  ORD-2026-0301
  //  ORD-2026-0302
  //  ORD-2026-0303
  //  ORD-2026-0304
  //  ORD-2026-0305
  //  ORD-2026-0306
  //  ORD-2026-0307
  //  ORD-2026-0308
  //  ORD-2026-0307
  //  First three e-mail addresses:
  //  alice.moore@example.com
  //  bkumar@example.org
  //  carla@example.net
  //  Occurrences of cat (any): 3
  //  Occurrences of cat (whole word): 1


  pdf.Free;
  json.Free;
  jsonOut.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.