text: //     ____   ______ __
  //    / __ \ / ____// /
  //   / /_/ // /    / /
  //  / ____// /___ / /___   PixInsight Class Library
  // /_/     \____//_____/   PCL 02.01.01.0784
  // ----------------------------------------------------------------------------
  // pcl/ExternalProcess.h - Released 2016/02/21 20:22:12 UTC
  // ----------------------------------------------------------------------------
  // This file is part of the PixInsight Class Library (PCL).
  // PCL is a multiplatform C++ framework for development of PixInsight modules.
  //
  // Copyright (c) 2003-2016 Pleiades Astrophoto S.L. All Rights Reserved.
  //
  // Redistribution and use in both source and binary forms, with or without
  // modification, is permitted provided that the following conditions are met:
  //
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  //    of their contributors, may be used to endorse or promote products derived
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  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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  // ----------------------------------------------------------------------------
  
  #ifndef __PCL_ExternalProcess_h
  #define __PCL_ExternalProcess_h
  
  /// \file pcl/ExternalProcess.h
  
  #ifndef __PCL_BUILDING_PIXINSIGHT_APPLICATION
  
  #ifndef __PCL_Defs_h
  #include <pcl/Defs.h>
  #endif
  
  #ifndef __PCL_UIObject_h
  #include <pcl/UIObject.h>
  #endif
  
  #ifndef __PCL_Flags_h
  #include <pcl/Flags.h>
  #endif
  
  #ifndef __PCL_AutoPointer_h
  #include <pcl/AutoPointer.h>
  #endif
  
  #ifndef __PCL_Control_h
  #include <pcl/Control.h>
  #endif
  
  namespace pcl
  {
  
  // ----------------------------------------------------------------------------
  
  /*!
   * \namespace ExternalProcessError
   * \brief External process error conditions.
   *
   * <table border="1" cellpadding="4" cellspacing="0">
   * <tr><td>ExternalProcessError::FailedToStart</td> <td>The external process failed to start.</td></tr>
   * <tr><td>ExternalProcessError::Crashed</td>       <td>The external process crashed.</td></tr>
   * <tr><td>ExternalProcessError::TimedOut</td>      <td>A wait operation timed out.</td></tr>
   * <tr><td>ExternalProcessError::ReadError</td>     <td>An error occurred while trying to read data from a process' stdout or stderr streams.</td></tr>
   * <tr><td>ExternalProcessError::WriteError</td>    <td>An error occurred while trying to write data to a process' stdin stream.</td></tr>
   * <tr><td>ExternalProcessError::UnknownError</td>  <td>An unknown error occurred trying to execute or communicate with an external process.</td></tr>
   * </table>
   */
  namespace ExternalProcessError
  {
     enum value_type
     {
        FailedToStart,
        Crashed,
        TimedOut,
        ReadError,
        WriteError,
        UnknownError
     };
  }
  
  // ----------------------------------------------------------------------------
  
  /*!
   * \class ExternalProcess
   * \brief Execution of external programs.
   *
   * %ExternalProcess is essentially a PCL wrapper to Qt's QProcess class, which
   * the PixInsight core application uses as the underlying implementation for
   * management of external processes on the PixInsight platform.
   *
   * ### TODO: Write a detailed description for %ExternalProcess.
   */
  class PCL_CLASS ExternalProcess : public UIObject
  {
  public:
  
  #ifndef __PCL_WINDOWS
     /*!
      * The type of a platform-dependent Process Identifier (PID).
      *
      * On Linux/UNIX (Linux, FreeBSD and Mac OS X), a PID is a 64-bit integer.
      *
      * On Windows platforms, a PID is a pointer to a _PROCESS_INFORMATION
      * structure (hence, on 64-bit Windows platforms a PID is also a 64-bit
      * integer number).
      */
     typedef int64  pid_type;
  #else
     typedef void*  pid_type;
  #endif
  
     /*!
      * The type used to represent error conditions in external processes.
      */
     typedef ExternalProcessError::value_type  error_code;
  
     /*!
      * Constructs an %ExternalProcess object.
      */
     ExternalProcess();
  
     /*!
      * Destroys the client-side %ExternalProcess instance and dereferences the
      * server-side object. If the server-side object becomes unreferenced, it
      * will be garbage-collected and eventually destroyed by the core
      * application.
      */
     virtual ~ExternalProcess()
     {
     }
  
     /*!
      * Ensures that the server-side object managed by this instance is uniquely
      * referenced.
      *
      * Since external processes are unique objects, calling this member function
      * has no effect.
      */
     virtual void EnsureUnique()
     {
     }
  
     /*!
      * Returns a reference to a null %ExternalProcess instance. A null
      * %ExternalProcess does not correspond to an existing external process in
      * the PixInsight core application.
      */
     static ExternalProcess& Null();
  
     /*!
      * Attempts to execute an external process.
      *
      * \param program    Path to the executable file.
      *
      * \param arguments  Optional list of command-line arguments that will be
      *                   passed to the executable. Arguments containing spaces
      *                   will be enclosed by quotes automatically. The default
      *                   value is an empty list.
      *
      * If the specified \a program cannot be executed for some reason (for
      * example, because the specified \a program does not exist, or because the
      * calling process doesn't have enough privileges), this function throws an
      * Error exception.
      *
      * This function implicitly opens the standard input, output and error I/O
      * streams (stdin, stdout and stderr, respectively) of the running process.
      * You can read from and write to the process using the Read() and Write()
      * member functions of %ExternalProcess, respectively. You can also close
      * the I/O streams using the CloseXX() member functions.
      */
     void Start( const String& program, const StringList& arguments = StringList() );
  
     /*!
      * Waits for the process to start execution.
      *
      * \param ms         Maximum waiting time in milliseconds. If a negative
      *                   value is specified, this function will never time out.
      *                   The default waiting time is 6000 ms (six seconds).
      *
      * This function suspends the calling task for at most the specified time,
      * or forever if a negative time value is specified. Returns true if the
      * process started before the specified time elapsed. Returns false if the
      * process timed out. In the latter case, this function can be called again
      * to continue waiting for the process to start.
      *
      * \warning When called from the root thread, this function can freeze the
      * entire PixInsight graphical interface. For asynchronous external process
      * execution, consider calling WaitForXX() functions from a separate thread.
      * Be aware that if you specify a large waiting time or a negative value,
      * this function may crash the calling thread.
      */
     bool WaitForStarted( int ms = 6000 );
  
     /*!
      * Waits for the running process to finish execution.
      *
      * \param ms         Maximum waiting time in milliseconds. If a negative
      *                   value is specified, this function will never time out.
      *                   The default waiting time is 6000 ms (six seconds).
      *
      * This function suspends the calling task for at most the specified time,
      * or forever if a negative time value is specified. Returns true if the
      * process finished its execution before the specified time elapsed. Returns
      * false if the process timed out. In the latter case, this function can be
      * called again to continue waiting for the process to finish.
      *
      * \warning When called from the root thread, this function can freeze the
      * entire PixInsight graphical interface. For asynchronous external process
      * execution, consider calling WaitForXX() functions from a separate thread.
      * Be aware that if you specify a large waiting time or a negative value,
      * this function may crash the calling thread.
      */
     bool WaitForFinished( int ms = 6000 );
  
     /*!
      * Waits for the running process to send data.
      *
      * \param ms         Maximum waiting time in milliseconds. If a negative
      *                   value is specified, this function will never time out.
      *                   The default waiting time is 6000 ms (six seconds).
      *
      * This function suspends the calling task for at most the specified time,
      * or forever if a negative time value is specified. Returns true if the
      * process sent some data through one of its output streams (standard output
      * or standard error) before the specified time elapsed. Returns false if
      * the process timed out. In the latter case, this function can be called
      * again to continue waiting for the process to generate output data. When
      * new output data is available from the process, it can be read immediately
      * by calling one of the Read() member functions.
      *
      * \warning When called from the root thread, this function can freeze the
      * entire PixInsight graphical interface. For asynchronous external process
      * execution, consider calling WaitForXX() functions from a separate thread.
      * Be aware that if you specify a large waiting time or a negative value,
      * this function may crash the calling thread.
      */
     bool WaitForDataAvailable( int ms = 6000 );
  
     /*!
      * Waits for the running process to receive data.
      *
      * \param ms         Maximum waiting time in milliseconds. If a negative
      *                   value is specified, this function will never time out.
      *                   The default waiting time is 6000 ms (six seconds).
      *
      * This function suspends the calling task for at most the specified time,
      * or forever if a negative time value is specified. Returns true if the
      * process received the data sent previously through its input stream (the
      * process' <em>standard input</em>) before the specified time elapsed.
      * Returns false if the process timed out. In the latter case, this function
      * can be called again to continue waiting for the process to fetch its
      * input data. Data can be sent to a running process by calling one of the
      * Write() member functions.
      *
      * \warning When called from the root thread, this function can freeze the
      * entire PixInsight graphical interface. For asynchronous external process
      * execution, consider calling WaitForXX() functions from a separate thread.
      * Be aware that if you specify a large waiting time or a negative value,
      * this function may crash the calling thread.
      */
     bool WaitForDataWritten( int ms = 6000 );
  
     /*!
      * Attempts to terminate the running process.
      *
      * On Linux/UNIX platforms (Linux, FreeBSD and Mac OS X) a SIGTERM signal is
      * sent to the process.
      *
      * On Windows, this function sends WM_CLOSE messages to all top-level
      * windows owned by the process and to its main thread. Console Windows
      * applications that don't have a message loop, or GUI Windows applications
      * that don't process WM_CLOSE messages adequately, cannot be terminated by
      * calling this member function. In these cases, the only way to terminate
      * the running process is by calling Kill().
      *
      * \note Note that there is no guarantee that the running process will
      * terminate after calling this function.
      */
     void Terminate();
  
     /*!
      * Forces termination of the running process.
      *
      * On Linux/UNIX platforms (Linux, FreeBSD and Mac OS X) a SIGKILL signal is
      * sent to the process.
      *
      * On Windows, the TerminateProcess() API function is called to force
      * process termination.
      *
      * \warning Unconditional termination of processes is always risky and
      * should be avoided. For example, the running program wil not have an
      * opportunity to close open files or save modified data. This function
      * should only be used as a last resort to terminate a process.
      */
     void Kill();
  
     /*!
      * Closes the standard input stream (stdin) of the running process.
      *
      * After calling this function, you no longer can write to the process using
      * one of the Write() member functions (doing so will always throw an Error
      * exception due to an I/O error).
      *
      * There are programs that require you to close the input stream explicitly.
      * An example is the 'cat' UNIX utility. For example, if you enter the 'cat'
      * command from a UNIX terminal, the program starts reading data from its
      * stdin stream (which is the terminal in this example) until you press the
      * "Ctrl+D" combination to close it.
      *
      * \note This function can only be called for a running process. If the
      * process is not running, an Error exception is thrown.
      */
     void CloseStandardInput();
  
     /*!
      * Closes the standard output stream (stdout) of the running process.
      *
      * After calling this function, you no longer can read data from the process
      * through its stdin stream. Calling this function can be useful to save
      * memory for processes that generate large amounts of output data, or if a
      * running process starts producing loads of data that you don't want to
      * process anymore.
      *
      * \note This function can only be called for a running process. If the
      * process is not running, an Error exception is thrown.
      */
     void CloseStandardOutput();
  
     /*!
      * Closes the standard error stream (stderr) of the running process.
      *
      * After calling this function, you no longer can read data from the process
      * through its stderr stream. Calling this function can be useful to save
      * memory for processes that generate large amounts of output data, or if a
      * running process starts producing loads of data that you don't want to
      * process anymore.
      *
      * \note This function can only be called for a running process. If the
      * process is not running, an Error exception is thrown.
      */
     void CloseStandardError();
  
     /*!
      * Redirects the standard output stream (stdout) of the process to the
      * specified file.
      *
      * \param filePath   Path to the file where the process will write its
      *                   standard output data.
      *
      * \param append     If true and the specified file already exists, its
      *                   contents will be preserved and newly generated data
      *                   will be appended. If false, the existing file will be
      *                   overwritten and its previous contents will be lost. The
      *                   default value is false (overwrite).
      *
      * Example:
      *
      * \code
      * ExternalProcess p1, p2;
      * p1.RedirectStandardOutput( "/tmp/foo.txt" );
      * p1.Start( "ls", StringList() << "-la" << "*.bar" );
      * \endcode
      *
      * The above code snippet is equivalent to this command:
      *
      * <tt>ls -la *.bar >/tmp/foo.txt</tt>
      *
      * \note This member function can only be called before running the process,
      * i.e. before calling Start(). Otherwise an Error exception is thrown.
      */
     void RedirectStandardOutput( const String& filePath, bool append = false );
  
     /*!
      * Redirects the standard output stream (stdout) of the process to the
      * specified process.
      *
      * \param process    Reference to a process where this process will write
      *                   its standard output data.
      *
      * This function can be used to build a \e pipe between two programs. For
      * example:
      *
      * \code
      * ExternalProcess p1, p2;
      * p1.RedirectStandardOutput( p2 );
      * p1.Start( "cat", StringList() << "*.bar" );
      * p2.Start( "grep", StringList() << "\'foo\'" );
      * \endcode
      *
      * would produce the same result as this command:
      *
      * <tt>cat *.bar |grep 'foo'</tt>
      *
      * \note This member function can only be called before running both
      * processes, i.e. before calling Start() for this process \e and the
      * specified \a process. Otherwise an Error exception is thrown.
      */
     void RedirectStandardOutput( ExternalProcess& process );
  
     /*!
      * Redirects the standard error output stream (stderr) of the process to the
      * specified file.
      *
      * \param filePath   Path to the file where the process will write its
      *                   standard error data.
      *
      * \param append     If true and the specified file already exists, its
      *                   contents will be preserved and newly generated data
      *                   will be appended. If false, the existing file will be
      *                   overwritten and its previous contents will be lost. The
      *                   default value is false (overwrite).
      *
      * For more information on redirection of process output, see the
      * RedirectStandardOutput() functions.
      */
     void RedirectStandardError( const String& filePath, bool append = false );
  
     /*!
      * Redirects the standard input stream (stdin) of the process from the
      * specified file.
      *
      * \param filePath   Path to an existing file from which the process will
      *                   read its standard input data. The current contents of
      *                   the file won't be modified or affected in any way by
      *                   calling this function.
      *
      * Example:
      *
      * \code
      * ExternalProcess p;
      * p.RedirectStandardInput( "/tmp/foo.txt" );
      * p.Start( "grep", StringList() << "\'bar\'" );
      * \endcode
      *
      * The above code snippet is equivalent to this command:
      *
      * <tt>grep 'bar' \</tmp/foo.txt</tt>
      *
      * \note This member function can only be called before running the process,
      * i.e. before calling Start(). Otherwise an Error exception is thrown.
      */
     void RedirectStandardInput( const String& filePath );
  
     /*!
      * Returns the working directory (aka folder) of this process.
      */
     String WorkingDirectory() const;
  
     /*!
      * Sets the working directory for this process.
      *
      * \param dirPath    Path to an existing directory, which will be the
      *                   working directory of the process when it is started.
      *
      * \note This member function can only be called before running the process,
      * i.e. before calling Start(). Otherwise an Error exception is thrown.
      */
     void SetWorkingDirectory( const String& dirPath );
  
     /*!
      * Returns true iff the process is running. An %ExternalProcess object
      * represents a running process briefly (usually) after calling its Start()
      * member function, when the IsStarting() function returns false, and just
      * before an OnStarted() event is generated.
      */
     bool IsRunning() const;
  
     /*!
      * Returns true iff the process is starting. An %ExternalProcess object
      * enters the starting state after calling its Start() member function, but
      * before the actual process is running.
      */
     bool IsStarting() const;
  
     /*!
      * Returns true iff the running process has crashed.
      */
     bool HasCrashed() const;
  
     /*!
      * Returns the platform-dependent Process Identifier (PID) of the running
      * process. See the ExternalProcess::pid_type type definition for more
      * information.
      *
      * If the process is not running this member function returns zero.
      */
     pid_type PID() const;
  
     /*!
      * Returns the exit code of the finished process. This is normally the
      * return value of the process' main() function.
      */
     int ExitCode() const;
  
     /*!
      * Returns the number of bytes waiting to be read from this running process.
      * If the process is not running, this member function returns zero.
      *
      * When this function returns a nonzero value, the available data can be
      * read by calling one of the Read() member functions.
      */
     size_type BytesAvailable() const;
  
     /*!
      * Returns the number of bytes pending to be written to this running
      * process. If the process is not running, this function returns zero.
      *
      * If this function returns a nonzero value, it is because one of the
      * Write() member functions has been called previously for this process with
      * nonempty data.
      */
     size_type BytesToWrite() const;
  
     /*!
      * Reads all the data available from the standard output stream (stdout) of
      * this process, and returns them as a ByteArray object.
      *
      * If the process has not sent any new data through its stdout stream, or if
      * the process is not running, an empty %ByteArray is returned. Note that
      * after the reading operation the stdout stream is cleared, i.e. the data
      * can only be read once.
      */
     ByteArray StandardOutput();
  
     /*!
      * Reads all the data available from the standard error stream (stderr) of
      * this process, and returns them as a ByteArray object.
      *
      * If the process has not sent any new data through its stderr stream, or if
      * the process is not running, an empty %ByteArray is returned. Note that
      * after the reading operation the stderr stream is cleared, i.e. the data
      * can only be read once.
      */
     ByteArray StandardError();
  
     /*!
      * Reads all the data available from the standard output and standard error
      * streams (stdout and stderr, respectively) of this process, and returns
      * them as a ByteArray object.
      *
      * If the process has not sent any new data through its output streams, or
      * if the process is not running, an empty %ByteArray is returned. Note that
      * after the reading operation, both stdout and stderr streams are cleared,
      * i.e. the data can only be read once.
      *
      * \note In the returned %ByteArray, the data from both stdout and stderr
      * streams will be mixed because they are gathered as they are generated. If
      * you need the data from both streams separately, call the StandardOutput()
      * and StandardError() member functions as appropriate.
      */
     ByteArray Read();
  
     /*!
      * Writes the specified \a data to the standard input stream (stdin) of this
      * process.
      */
     void Write( const ByteArray& data );
  
     /*!
      * Writes the specified \a text to the standard input stream (stdin) of this
      * process. The specified UTF-16 string will be treated as a sequence of
      * bytes, and the terminating null character of the string (two bytes) will
      * be excluded.
      */
     void Write( const String& text );
  
     /*!
      * Writes the specified \a text to the standard input stream (stdin) of this
      * process. The specified 8-bit string will be treated as a sequence of
      * bytes, and the terminating null character of the string will be excluded.
      */
     void Write( const IsoString& text );
  
     /*!
      * Writes the specified \a text to the standard input stream (stdin) of this
      * process. The specified 8-bit string will be treated as a sequence of
      * bytes, and the terminating null character of the string will be excluded.
      */
     void Write( const char* text );
  
     /*!
      * Writes \a count contiguous bytes starting at the specified \a data
      * location to the standard input stream (stdin) of this process.
      */
     void Write( const void* data, size_type count );
  
     /*!
      * Returns the list of environment variables for this process. Environment
      * variables are 'name=value' items that most programs can interpret to
      * modify their functionality.
      *
      * If no environment has been set for this process, an empty list is
      * returned.
      */
     StringList Environment() const;
  
     /*!
      * Sets the \a environment for this process.
      *
      * The environment is a list of 'name=value' elements, knwon as
      * <em>environment variables</em>, that most programs can interpret to
      * modify their functionality.
      *
      * If no environment is explicitly set for a process, it will inherit the
      * environment of the calling process.
      *
      * \note This member function can only be called before running the process,
      * i.e. before calling Start(). Otherwise an Error exception is thrown.
      */
     void SetEnvironment( const StringList& environment );
  
     /*!
      * \defgroup external_process_event_handlers ExternalProcess Event Handlers
      */
  
     /*!
      * Defines the prototype of a <em>process event handler</em>.
      *
      * A process event is generated when an %ExternalProcess instance changes
      * its state, or generates a simple notification.
      *
      * \param sender  The object that sends a process event.
      *
      * \ingroup external_process_event_handlers
      */
     typedef void (Control::*process_event_handler)( ExternalProcess& sender );
  
     /*!
      * Defines the prototype of a <em>process exit event handler</em>.
      *
      * A process exit event is generated when an %ExternalProcess instance
      * notifies that a running process has finished execution.
      *
      * \param sender     The object that sends a process exit event.
      *
      * \param exitCode   The process' exit code. Typically, this is the return
      *                   value of the main() function in the process.
      *
      * \param exitOk     True if the process finished execution normally. False
      *                   if the process crashed.
      *
      * \ingroup external_process_event_handlers
      */
     typedef void (Control::*process_exit_event_handler)( ExternalProcess& sender, int exitCode, bool exitOk );
  
     /*!
      * Defines the prototype of a <em>process error event handler</em>.
      *
      * A process error event is generated when an %ExternalProcess instance
      * reports an error condition, such as an I/O error, a nonexistent
      * executable file or lack of execution permissions.
      *
      * \param sender  The object that sends a process error event.
      *
      * \param error   Identifies the error condition that generated the event.
      *
      * \ingroup external_process_event_handlers
      */
     typedef void (Control::*process_error_event_handler)( ExternalProcess& sender, error_code error );
  
     /*!
      * Sets the handler for <em>process started</em> events generated by this
      * %ExternalProcess object. A process started event is generated when the
      * process has just started and is running.
      *
      * \param handler    The event handler. Must be a member function of the
      *                   \a receiver object's class.
      *
      * \param receiver   The control that will receive process started events
      *                   from this object.
      *
      * \ingroup external_process_event_handlers
      */
     void OnStarted( process_event_handler handler, Control& receiver );
  
     /*!
      * Sets the handler for <em>process finished</em> events generated by this
      * %ExternalProcess object. A process finished event is generated when the
      * running process has just finished execution.
      *
      * \param handler    The event handler. Must be a member function of the
      *                   \a receiver object's class.
      *
      * \param receiver   The control that will receive process finished events
      *                   from this object.
      *
      * \ingroup external_process_event_handlers
      */
     void OnFinished( process_exit_event_handler handler, Control& receiver );
  
     /*!
      * Sets the handler for <em>stdout data available</em> events generated by
      * this %ExternalProcess object. These events are generated when the running
      * process sends data through its standard output stream, and the data is
      * ready to be read.
      *
      * \param handler    The event handler. Must be a member function of the
      *                   \a receiver object's class.
      *
      * \param receiver   The control that will receive stdout data available
      *                   events from this object.
      *
      * \ingroup external_process_event_handlers
      */
     void OnStandardOutputDataAvailable( process_event_handler handler, Control& receiver );
  
     /*!
      * Sets the handler for <em>stderr data available</em> events generated by
      * this %ExternalProcess object. These events are generated when the running
      * process sends data through its standard error stream, and the data is
      * ready to be read.
      *
      * \param handler    The event handler. Must be a member function of the
      *                   \a receiver object's class.
      *
      * \param receiver   The control that will receive stderr data available
      *                   events from this object.
      *
      * \ingroup external_process_event_handlers
      */
     void OnStandardErrorDataAvailable( process_event_handler handler, Control& receiver );
  
     /*!
      * Sets the handler for <em>process error</em> events generated by this
      * %ExternalProcess object. A process error event is generated when the
      * process reports an error condition.
      *
      * \param handler    The event handler. Must be a member function of the
      *                   \a receiver object's class.
      *
      * \param receiver   The control that will receive process error events
      *                   from this object.
      *
      * \ingroup external_process_event_handlers
      */
     void OnError( process_error_event_handler handler, Control& receiver );
  
     /*!
      * Executes a program as a child process and waits for it to terminate.
      *
      * \param program    Path to an existing executable file.
      *
      * \param arguments  Optional list of command-line arguments that will be
      *                   passed to the executable. Arguments containing spaces
      *                   will be enclosed by quotes automatically. The default
      *                   value is an empty list.
      *
      * Returns the program's exit code. If the specified \a program cannot be
      * executed, this member function throws an Error exception.
      */
     static int ExecuteProgram( const String& program, const StringList& arguments = StringList() );
  
     /*!
      * Executes a program as an independent process.
      *
      * \param program    Path to an existing executable file.
      *
      * \param arguments  Optional list of command-line arguments that will be
      *                   passed to the executable. Arguments containing spaces
      *                   will be enclosed by quotes automatically. The default
      *                   value is an empty list.
      *
      * \param workingDirectory Path to an existing directory, which will be the
      *                   working directory of the process. The default value is
      *                   an empty string.
      *
      * The program is executed as a standalone process, also known as a
      * \e daemon on Linux/UNIX. It can continue running after the calling
      * application terminates.
      *
      * Returns the platform-dependent process identifier (PID) of the running
      * process. If the specified \a program cannot be executed, this member
      * function throws an Error exception.
      */
     static pid_type StartProgram( const String& program,
                                   const StringList& arguments = StringList(),
                                   const String& workingDirectory = String() );
  
  private:
  
     struct EventHandlers
     {
        process_event_handler       onStarted                     = nullptr;
        process_exit_event_handler  onFinished                    = nullptr;
        process_event_handler       onStandardOutputDataAvailable = nullptr;
        process_event_handler       onStandardErrorDataAvailable  = nullptr;
        process_error_event_handler onError                       = nullptr;
  
        EventHandlers() = default;
        EventHandlers( const EventHandlers& ) = default;
        EventHandlers& operator =( const EventHandlers& ) = default;
     };
  
     AutoPointer<EventHandlers> m_handlers;
  
     ExternalProcess( void* );
     virtual void* CloneHandle() const;
  
     ExternalProcess( const ExternalProcess& ) = delete;
     ExternalProcess& operator =( const ExternalProcess& ) = delete;
     ExternalProcess( ExternalProcess&& ) = delete;
     ExternalProcess& operator =( ExternalProcess&& ) = delete;
  
     friend class ExternalProcessPrivate;
     friend class ExternalProcessEventDispatcher;
  };
  
  // ----------------------------------------------------------------------------
  
  } // pcl
  
  #endif   // __PCL_BUILDING_PIXINSIGHT_APPLICATION
  
  #endif   // __PCL_ExternalProcess_h
  
  // ----------------------------------------------------------------------------
  // EOF pcl/ExternalProcess.h - Released 2016/02/21 20:22:12 UTC
  