PipeExec Control

Properties   Methods   Events   Config Settings   Errors  

PipeExec provides an easy way to start and interact with a process over Stdin, Stdout, and Stderr.

Syntax

PipeExec

Remarks

The PipeExec component provides a way to launch a process and then send/receive data to/from the process. To begin set ProcessFileName to the path of the process on disk. Optionally set ProcessArgs and ProcessWorkingDir.

Call StartProcess to start the process. Next call Send to send data to the process. Received data will be provided through the Stdout and Stderr events.

To terminate the process call StopProcess.

Example Code Pipeexec exec = new Pipeexec(); exec.OnStdout += exec_OnStdout; exec.ProcessFileName = @"C:\Windows\system32\cmd.exe"; exec.ProcessArgs = "/Q"; exec.StartProcess(); exec.Stdin = "dir" + System.Environment.NewLine; while (true) //Wait for output exec.DoEvents(); static void exec_OnStdout(object sender, PipeexecStdoutEventArgs e) { Console.WriteLine(e.Text); }

Property List

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The following is the full list of the properties of the control with short descriptions. Click on the links for further details.

Method List

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The following is the full list of the methods of the control with short descriptions. Click on the links for further details.

Event List

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The following is the full list of the events fired by the control with short descriptions. Click on the links for further details.

Config Settings

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The following is a list of config settings for the control with short descriptions. Click on the links for further details.

AcceptData Property (PipeExec Control)

Enables or disables data reception (the Stdout and Stderr events).

Syntax

pipeexeccontrol.AcceptData[=boolean]

Default Value

True

Remarks

This property enables or disables data reception (the Stdout and Stderr events). Setting this property to False, temporarily disables data reception. Setting this property to True, re-enables data reception.

This property is not available at design time.

Data Type

Boolean

BytesSent Property (PipeExec Control)

The number of bytes actually sent after a call to the SendStdinText or SendStdinBytes method.

Syntax

pipeexeccontrol.BytesSent

Default Value

0

Remarks

This property indicates how many bytes were sent after the last call to SendStdinText or SendStdinBytes. Please check the SendStdinText or SendStdinBytes method for more information. Note: that BytesSent will always return 0 when the component is operating in synchronous mode (i.e., the Timeout property is set to a positive value.)

This property is read-only and not available at design time.

Data Type

Integer

EOL Property (PipeExec Control)

This property is used to break the incoming data stream into chunks separated by EOL .

Syntax

pipeexeccontrol.EOL[=string]

Default Value

""

Remarks

This property is used to define boundaries in the input stream using the value of the property.

This property is especially useful with ASCII files. Setting it to CRLF (Chr$(13) & Chr$(10)) enables the incoming ASCII text stream to split into defined lines. In this case, one event is fired for each line received (as well as in packet boundaries). The CRLF (Chr$(13) & Chr$(10)) bytes are discarded.

This property is a binary string. Notably, this means that it can be more than one byte long, and it can contain NULL bytes.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .EOLB.

Data Type

Binary String

ProcessArgs Property (PipeExec Control)

The arguments to pass to the process.

Syntax

pipeexeccontrol.ProcessArgs[=string]

Default Value

""

Remarks

This property specifies the arguments that will be passed to the process when it is started.

This property is not available at design time.

Data Type

String

ProcessFileName Property (PipeExec Control)

The path to the file on disk to execute.

Syntax

pipeexeccontrol.ProcessFileName[=string]

Default Value

""

Remarks

This property specifies the path to the file on disk that will be executed. ProcessArgs optionally specifies the arguments that will be passed. ProcessWorkingDir optionally specifies the working directory in which the process will run.

This property is not available at design time.

Data Type

String

ProcessRunning Property (PipeExec Control)

Whether the process is running.

Syntax

pipeexeccontrol.ProcessRunning

Default Value

False

Remarks

This property indicates whether the process specified by ProcessFileName is running.

After calling StartProcess this property returns True. After calling StopProcess this property returns False.

This property is read-only and not available at design time.

Data Type

Boolean

ProcessWorkingDir Property (PipeExec Control)

The working directory of the process.

Syntax

pipeexeccontrol.ProcessWorkingDir[=string]

Default Value

""

Remarks

This property optionally specifies the working directory in which the process will run.

This property is not available at design time.

Data Type

String

SingleLineMode Property (PipeExec Control)

This property includes a special mode for line-oriented protocols.

Syntax

pipeexeccontrol.SingleLineMode[=boolean]

Default Value

False

Remarks

When this property is set to True, the control treats the incoming data stream as lines separated by carriage return line feed (CRLF), CR, or LF. The EOL property is ignored.

When this property is set to True, AcceptData automatically will be set to False. Please refer to the GetLine method for more information.

This property is not available at design time.

Data Type

Boolean

Timeout Property (PipeExec Control)

This property includes the timeout for the control.

Syntax

pipeexeccontrol.Timeout[=integer]

Default Value

60

Remarks

If the Timeout property is set to 0, all operations return immediately, potentially failing with a WOULDBLOCK error if data cannot be sent immediately.

If Timeout is set to a positive value, data is sent in a blocking manner and the control will wait for the operation to complete before returning control. The control will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of Timeout seconds.

The control will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not freeze and remains responsive.

If Timeout expires, and the operation is not yet complete, the control fails with an error.

Note: By default, all timeouts are inactivity timeouts, that is, the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the Timeout property is 60 seconds.

Data Type

Integer

Config Method (PipeExec Control)

Sets or retrieves a configuration setting.

Syntax

pipeexeccontrol.Config ConfigurationString

Remarks

Config is a generic method available in every control. It is used to set and retrieve configuration settings for the control.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the control, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

DoEvents Method (PipeExec Control)

This method processes events from the internal message queue.

Syntax

pipeexeccontrol.DoEvents 

Remarks

When DoEvents is called, the control processes any available events. If no events are available, it waits for a preset period of time, and then returns.

GetLine Method (PipeExec Control)

This method gets a line of text from the server.

Syntax

pipeexeccontrol.GetLine 

Remarks

This method gets a line of text from the server. This method is an alternative method of receiving data for line-oriented protocols. The control will block if necessary and then will return the received line. AcceptData will be set automatically to True when the method is called, and then will be set to False after a line is received.

Please refer to the SingleLineMode property for more information.

Interrupt Method (PipeExec Control)

This method interrupts the current action.

Syntax

pipeexeccontrol.Interrupt 

Remarks

This method interrupts the current action. If you use SendFile to upload a file, the control will run synchronously until the upload is completed. This method will allow you to stop the file from uploading without disconnecting from the host.

Send Method (PipeExec Control)

Sends data over the connected pipe.

Syntax

pipeexeccontrol.Send Text

Remarks

This method sends data to the server.

SendFile Method (PipeExec Control)

Sends the file over the connected pipe.

Syntax

pipeexeccontrol.SendFile FileName

Remarks

This method sends the specified file to the server/process over the connected pipe.

Timeout must be set to a positive value so that the control will operate synchronously.

SendLine Method (PipeExec Control)

This method sends a string followed by a newline.

Syntax

pipeexeccontrol.SendLine Text

Remarks

This method sends a string followed by a newline. This method is used to send data with line-oriented protocols. The line is followed by CRLF (Chr$(13) & Chr$(10)) .

Please refer to the GetLine method and SingleLineMode property for more information.

SendStdinBytes Method (PipeExec Control)

This method sends binary data over the connected pipe.

Syntax

pipeexeccontrol.SendStdinBytes Data

Remarks

This method sends the specified binary data to the server over Stdin. To send text, use the SendStdinText method instead.

When Timeout is set to 0 the control will behave asynchronously. If you are sending data to the receiving process faster than it can process it, the outgoing queue might fill up. When this happens, the control fails with error 25036: "[10035] Operation would block" (WSAEWOULDBLOCK). You can trap this error, and then try to send the data again. The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the ReadyToSend event before attempting to send data again. (However, please note that ReadyToSend is not fired when part of the data is successfully sent).

SendStdinText Method (PipeExec Control)

This method sends text over the connected pipe.

Syntax

pipeexeccontrol.SendStdinText Text

Remarks

This method sends the specified text to the server over Stdin. To send binary data, use the SendStdinBytes method instead.

When Timeout is set to 0 the control will behave asynchronously. If you are sending data to the receiving process faster than it can process it, the outgoing queue might fill up. When this happens, the control fails with error 25036: "[10035] Operation would block" (WSAEWOULDBLOCK). You can trap this error, and then try to send the data again. The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the ReadyToSend event before attempting to send data again. (However, please note that ReadyToSend is not fired when part of the data is successfully sent).

StartProcess Method (PipeExec Control)

Starts the process.

Syntax

pipeexeccontrol.StartProcess 

Remarks

This method starts the process specified by StartProcess. After starting the process data may be sent to the process by calling Send, SendLine, Send.

Data received from the process will be available from the Stdout and Stderr events.

The following properties are applicable when calling this method:

• ProcessFileName (required)
• ProcessArgs
• ProcessWorkingDir

StopProcess Method (PipeExec Control)

Stops the process.

Syntax

pipeexeccontrol.StopProcess 

Remarks

This method stops the process.

Error Event (PipeExec Control)

Fired when information is available about errors during data delivery.

Syntax

Sub pipeexeccontrol_Error(ErrorCode As Integer, Description As String)

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the control fails with an error.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

ReadyToSend Event (PipeExec Control)

Fired when the control is ready to send data.

Syntax

Sub pipeexeccontrol_ReadyToSend()

Remarks

The ReadyToSend event indicates that the underlying pipe is ready to accept data again after a failed send. The event is also fired immediately after a connection to the remote host is established.

Stderr Event (PipeExec Control)

Fired when data come in through stderr.

Syntax

Sub pipeexeccontrol_Stderr(Text As String, EOL As Boolean)

Remarks

The Stderr event is fired every time the process outputs a line in its standard output. The incoming data is provided through the Text parameter.

Stdout Event (PipeExec Control)

Fired when data come in through stdout.

Syntax

Sub pipeexeccontrol_Stdout(Text As String, EOL As Boolean)

Remarks

The Stdout event is fired every time the process outputs a line in its standard output. The incoming data is provided through the Text parameter.

EOL indicates whether or not the EOL string was found at the end of Text. If the EOL string was found, then EOL is True.

If Text is part of a data portion of length larger than MaxLineLength with no EOL strings in it, then EOL is False. Note: This means that one or more DataIn events with EOL set to False can be received during a connection.

If the EOL property is "" (empty string), then EOL can be disregarded (it is always True).

Config Settings (PipeExec Control)

The control accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the control, access to these internal properties is provided through the Config method.

PipeExec Config Settings

Base Config Settings

Trappable Errors (PipeExec Control)

PipeExec Errors