TChilkatScp Delphi ActiveX Reference Documentation

TChilkatScp

An API for SCP over SSH. (SCP is the Secure Copy Protocol.) It is for transferring files or directory trees to or from remote servers. SCP is a simpler protocol than SFTP, and thus the functionality is more limited. However, SCP does not require that an SSH server support the SFTP subsystem. In cases where a server does not allow for SFTP, then SCP is a good choice for file transfer.

Importing the Chilkat ActiveX into Delphi

Important: Whenever upgrading to a new version of Chilkat, make sure to re-imported ActiveX DLL into Delphi to regenerate the files described below.

Two things are required to use an ActiveX in Delphi:

  1. The ActiveX DLL needs to be registered via regsvr32 on the system where the Delphi application runs. See How To Register ActiveX DLLs for detailed information.
  2. The ActiveX component needs to be "imported". Use the Delphi Import Component Wizard to import the Chilkat type library. This creates the following files: Chilkat_v9_5_0_TLB.pas and Chilkat_v9_5_0_TLB.dcr. The Chilkat_v9_5_0_TLB.pas should be added to your project.

To import the Chilkat type library, do the following:

  1. In the Delphi RAD Studio, select the menu item "Component" --> "Import a Type Library".
  2. Find "Chilkat ActiveX v9.5.0" in the list and select it. This will only appear in the list if the ChilkatAx-9.5.0-win32.dll (or ChilkatAx-9.5.0-x64.dll) has been registered w/ regsvr32.
  3. Check the "Generate Component Wrappers" checkbox.
  4. Select a directory where the unit files (.pas and .dcr) will be generated.
  5. Select "Create Unit" and then "Finish".
  6. Add the .pas to your Delphi project.

To use a Chilkat ActiveX object in your Delphi code, add "Chilkat_v9_5_0_TLB" to the "uses" statement. For example:

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_v9_5_0_TLB;

Object Creation

var
obj: TChilkatScp;
...
begin
obj := TChilkatScp.Create(Self);
...
// When finished, free the object instance.
obj.Free();

Properties

property AbortCurrent: Integer

Introduced in version 9.5.0.58

When set to 1, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to 0 when the next method is called. When the abort occurs, this property is reset to 0. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

property DebugLogFilePath: WideString

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

property HeartbeatMs: Integer

This is the number of milliseconds between each AbortCheck event callback. The AbortCheck callback allows an application to abort any SSH operation prior to completion. If HeartbeatMs is 0 (the default), no AbortCheck event callbacks will fire.

property LastBinaryResult: OleVariant readonly

Introduced in version 9.5.0.52

The binary data returned by the last (binary data returning) method called. Only available if Chilkat.Global.KeepBinaryResult is set to 1. This provides a means for obtaining large varbinary results in the SQL Server environment (where limitations exist in getting large amounts of data returned by method calls, but where temp tables can be used for binary properties).

property LastErrorHtml: WideString readonly

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

property LastErrorText: WideString readonly

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Concept of LastErrorText

LastErrorText Standard Information

property LastErrorXml: WideString readonly

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

property LastMethodSuccess: Integer

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of 1 indicates success, a value of 0 indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = 1 and failure = 0.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to 1. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

property LastStringResult: WideString readonly

Introduced in version 9.5.0.52

The string return value of the last (string returning) method called. Only available if Chilkat.Global.KeepStringResult is set to 1. This provides a means for obtaining large string results in the SQL Server environment (where limitations exist in getting long strings returned by method calls, but where temp tables can be used for string properties).

Long Strings Returned by ActiveX Methods in SQL Server

property LastStringResultLen: Integer readonly

Introduced in version 9.5.0.53

The length, in characters, of the string contained in the LastStringResult property.

property PercentDoneScale: Integer

Introduced in version 9.5.0.51

This property is only valid in programming environment and languages that allow for event callbacks.

Sets the value to be defined as 100% complete for the purpose of PercentDone event callbacks. The defaut value of 100 means that at most 100 event PercentDone callbacks will occur in a method that (1) is event enabled and (2) is such that it is possible to measure progress as a percentage completed. This property may be set to larger numbers to get more fine-grained PercentDone callbacks. For example, setting this property equal to 1000 will provide callbacks with .1 percent granularity. For example, a value of 453 would indicate 45.3% competed. This property is clamped to a minimum value of 10, and a maximum value of 100000.

property SyncedFiles: WideString

Introduced in version 9.5.0.51

The paths of the files uploaded or downloaded in the last call to SyncUploadTree or SyncDownloadTree. The paths are listed one per line. In both cases (for upload and download) each line contains the full local file path (not the remote path).

SCP Sync Tree Download

SCP Sync Tree Upload

property SyncMustMatch: WideString

Introduced in version 9.5.0.51

Can contain a wildcarded list of filename patterns separated by semicolons. For example, "*.xml; *.txt; *.csv". If set, the SyncTreeUpload and SyncTreeDownload methods will only transfer files having a filename that matches any one of these patterns.

SCP Sync Tree Download

SCP Sync Tree Upload

SCP Download Files Matching a Pattern, such as *.txt

property SyncMustMatchDir: WideString

Introduced in version 9.5.0.58

Can contain a wildcarded list of directory name patterns separated by semicolons. For example, "a*; b*; c*". If set, the SyncTreeUpload and SyncTreeDownload methods will only traverse into a directory that matches any one of these patterns.

property SyncMustNotMatch: WideString

Introduced in version 9.5.0.51

Can contain a wildcarded list of filename patterns separated by semicolons. For example, "*.xml; *.txt; *.csv". If set, the SyncTreeUpload and SyncTreeDownload methods will not transfer files having a filename that matches any one of these patterns.

SCP Sync Tree Download

SCP Sync Tree Upload

property SyncMustNotMatchDir: WideString

Introduced in version 9.5.0.58

Can contain a wildcarded list of directory name patterns separated by semicolons. For example, "a*; b*; c*". If set, the SyncTreeUpload and SyncTreeDownload methods will not traverse into a directory that matches any one of these patterns.

property VerboseLogging: Integer

If set to 1, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is 0. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

property Version: WideString readonly

Version of the component/library, such as "9.4.1.42"

Methods

function DownloadBinary(remotePath: WideString): OleVariant;

Introduced in version 9.5.0.51

Downloads a binary file from the SSH server and returns the contents.

Returns a zero-length byte array (as an OleVariant) on failure.
An empty array will have a VarArrayHighBound of -1 meaning 0 elements.

function DownloadBinaryAsync(remotePath: WideString): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the DownloadBinary method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function DownloadBinaryEncoded(remotePath: WideString; encoding: WideString): WideString;

Introduced in version 9.5.0.51

Downloads a file from the SSH server returns the contents in an encoded string (using an encoding such as base64).

Returns a zero-length WideString on failure

List of Supported Encodings (Base64, Hex, etc.)

SCP Download/Upload Binary Files as Encoded Strings

function DownloadBinaryEncodedAsync(remotePath: WideString; encoding: WideString): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the DownloadBinaryEncoded method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function DownloadFile(remotePath: WideString; localPath: WideString): Integer;

Introduced in version 9.5.0.51

Downloads a file from the remote SSH server to the local filesystem.

Returns 1 for success, 0 for failure.

SCP Download File

SCP Download from a Specific Directory

function DownloadFileAsync(remotePath: WideString; localPath: WideString): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the DownloadFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function DownloadString(remotePath: WideString; charset: WideString): WideString;

Introduced in version 9.5.0.51

Downloads a text file from the SSH server and returns the contents as a string.

Returns a zero-length WideString on failure

SCP Download Text File to String Variable

function DownloadStringAsync(remotePath: WideString; charset: WideString): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the DownloadString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function SyncTreeDownload(remoteRoot: WideString; localRoot: WideString; mode: Integer; bRecurse: Integer): Integer;

Introduced in version 9.5.0.51

Downloads files from the SSH server to a local directory tree. Synchronization modes include:

mode=0: Download all files
mode=1: Download all files that do not exist on the local filesystem.
mode=2: Download newer or non-existant files.
mode=3: Download only newer files. If a file does not already exist on the local filesystem, it is not downloaded from the server.
mode=5: Download only missing files or files with size differences.
mode=6: Same as mode 5, but also download newer files.

Returns 1 for success, 0 for failure.

SCP Sync Tree Download

function SyncTreeDownloadAsync(remoteRoot: WideString; localRoot: WideString; mode: Integer; bRecurse: Integer): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the SyncTreeDownload method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function SyncTreeUpload(localBaseDir: WideString; remoteBaseDir: WideString; mode: Integer; bRecurse: Integer): Integer;

Introduced in version 9.5.0.51

Uploads a directory tree from the local filesystem to the SSH server. Synchronization modes include:

mode=0: Upload all files
mode=1: Upload all files that do not exist on the FTP server.
mode=2: Upload newer or non-existant files.
mode=3: Upload only newer files. If a file does not already exist on the FTP server, it is not uploaded.
mode=4: transfer missing files or files with size differences.
mode=5: same as mode 4, but also newer files.

Returns 1 for success, 0 for failure.

function SyncTreeUploadAsync(localBaseDir: WideString; remoteBaseDir: WideString; mode: Integer; bRecurse: Integer): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the SyncTreeUpload method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function UploadBinary(remotePath: WideString; binData: OleVariant): Integer;

Introduced in version 9.5.0.51

Uploads binary data to a file on the SSH server.

Returns 1 for success, 0 for failure.

function UploadBinaryAsync(remotePath: WideString; binData: OleVariant): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the UploadBinary method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function UploadBinaryEncoded(remotePath: WideString; encodedData: WideString; encoding: WideString): Integer;

Introduced in version 9.5.0.51

Uploads the binary data to a file on the remote SSH server. The binary data is passed in encoded string representation (such as base64, or hex).

Returns 1 for success, 0 for failure.

List of Supported Encodings (Base64, Hex, etc.)

SCP Download/Upload Binary Files as Encoded Strings

function UploadBinaryEncodedAsync(remotePath: WideString; encodedData: WideString; encoding: WideString): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the UploadBinaryEncoded method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function UploadFile(localPath: WideString; remotePath: WideString): Integer;

Introduced in version 9.5.0.51

Uploads a file from the local filesystem to the remote SSH server.

Returns 1 for success, 0 for failure.

SCP Upload File

SCP Upload to a Specific Remote Directory

function UploadFileAsync(localPath: WideString; remotePath: WideString): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the UploadFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function UploadString(remotePath: WideString; textData: WideString; charset: WideString): Integer;

Introduced in version 9.5.0.51

Uploads the contents of a string to a file on the remote SSH server.

Returns 1 for success, 0 for failure.

SCP Upload Contents of String to Remote File

function UploadStringAsync(remotePath: WideString; textData: WideString; charset: WideString): TChilkatTask;

Introduced in version 9.5.0.51

Creates an asynchronous task to call the UploadString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

How to Run an Asynchronous Task

function UseSsh(sshConnection: TChilkatSsh): Integer;

Introduced in version 9.5.0.51

Uses the SSH connection of sshConnection for the SCP transfers. All of the connection and socket related properties, proxy properites, timeout properties, session log, etc. set on the SSH object apply to the SCP methods (because internally it is the SSH object that is used to do the work of the file transfers).

Note: There is no UnlockComponent method in the SCP class because it is the SSH object that must be unlocked. When the SSH object is not unlocked, this method will return 0 to indicate failure.

Returns 1 for success, 0 for failure.

Events

procedure AbortCheck(ASender: TObject; out abort: Integer);

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200.

Delphi ActiveX Event callback implementation:

procedure TForm1.scpAbortCheck(ASender: TObject;  out abort: Integer);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  scp: TChilkatScp;

begin
  scp := TChilkatScp.Create(Self);
  scp.OnAbortCheck := scpAbortCheck;
  // ...

procedure BinaryData(ASender: TObject; data: OleVariant; length: Integer);

Binary data provided by certain methods.

Delphi ActiveX Event callback implementation:

procedure TForm1.scpBinaryData(ASender: TObject;  data: OleVariant; length: Integer);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  scp: TChilkatScp;

begin
  scp := TChilkatScp.Create(Self);
  scp.OnBinaryData := scpBinaryData;
  // ...

procedure PercentDone(ASender: TObject; pctDone: Integer; out abort: Integer);

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

The abort output argument provides a means for aborting the operation. Setting it to 1 will cause the method to abort and return a failed status (or whatever return value indicates failure).

Delphi ActiveX Event callback implementation:

procedure TForm1.scpPercentDone(ASender: TObject;  pctDone: Integer; out abort: Integer);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  scp: TChilkatScp;

begin
  scp := TChilkatScp.Create(Self);
  scp.OnPercentDone := scpPercentDone;
  // ...

procedure ProgressInfo(ASender: TObject; const name: WideString; const value: WideString);

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

Delphi ActiveX Event callback implementation:

procedure TForm1.scpProgressInfo(ASender: TObject;  const name: WideString; const value: WideString);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  scp: TChilkatScp;

begin
  scp := TChilkatScp.Create(Self);
  scp.OnProgressInfo := scpProgressInfo;
  // ...

procedure TaskCompleted(ASender: TObject; const task: IChilkatTask);

Called in the background thread when an asynchronous task completes.

Delphi TaskCompleted Event Callback Example

Delphi ActiveX Event callback implementation:

procedure TForm1.scpTaskCompleted(ASender: TObject;  const task: IChilkatTask);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  scp: TChilkatScp;

begin
  scp := TChilkatScp.Create(Self);
  scp.OnTaskCompleted := scpTaskCompleted;
  // ...

procedure TextData(ASender: TObject; const data: WideString);

Text data provided by certain methods.

Delphi ActiveX Event callback implementation:

procedure TForm1.scpTextData(ASender: TObject;  const data: WideString);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  scp: TChilkatScp;

begin
  scp := TChilkatScp.Create(Self);
  scp.OnTextData := scpTextData;
  // ...