VkProgram(3x)

NAME
     VkProgram - Object-oriented interface to subprogram execution

INHERITS FROM
     VkCallbackObject :

HEADER FILE
     #include <Vk/VkProgram.h>

PUBLIC PROTOCOL SUMMARY
   Constructor/Destructor
           VkProgram(const char* cmd, int killChildOnExit = 1);
           virtual void ~VkProgram(void);


   Control Functions
           virtual VkSubProcess run(void);


   Setup Functions
           void redirectIn(int do_redirect);


PROTECTED PROTOCOL SUMMARY
   Protected Data Members
           char* _cmd;
           const int _killChildOnExit;
           int _redirectIn;


CLASS DESCRIPTION
          The VkProgram class is an object-oriented interface to fork/exec.
          It spawns a program and passes the output back to the application.



FUNCTION DESCRIPTIONS
   VkProgram()
           VkProgram(const char* cmd,
                     int killChildOnExit = 1);
           virtual void ~VkProgram(void);


          Sets up the VkProgram object.  The first argument specifies a
          command to execute when the run() method is called.  The second
          argument indicates that the running child, if any, should be killed
          whenever this process exits.

   run()
          virtual VkSubProcess run(void);

          Forks and execs a child process, running the command specified in
          the constructor.  Returns the VkSubProcess object created as a
          result.

   redirectIn()
          void redirectIn(int do_redirect);


          If the argument is non-zero, indicates that an input pipe should be
          setup when the child process is created, giving the application the
          ability to send input to the process.

DATA MEMBER DESCRIPTIONS
   _cmd
          char* _cmd;


          The command to be executed.

   _killChildOnExit
          const int _killChildOnExit;


          Whether to set the child process options so that it terminates
          whenever the parent process terminates.

   _redirectIn
          int _redirectIn;


          Whether to setup an input pipe.

   exitCallback
          static const const char* exitCallback;


          This callback is called when the child process exits. The callData
          is an integer (cast to type void *) that reports the exit status.
          This callback is passed on to an instance of VkSubProcess, so the
          VkCallbackObject passed as the first argument is actually an
          instance of VkSubProcess.

   stdoutCallback
          static const const char* stdoutCallback;


          This callback is called when the child process has output directed
          to stdout. The VkCallbackObject pointer passed as the first argument
          is a VkInput object, because this callback is passed down a chain of
          objects that ultimately ends with a VkInput object that handled
          input from stdout.
   stderrCallback
          static const const char* stderrCallback;


          This callback is called when the child process has output directed
          to stderr. The VkCallbackObject pointer passed as the first argument
          is a VkInput object, because this callback is passed down a chain of
          objects that ultimately ends with a VkInput object that handled
          input from stderr.

INHERITED MEMBER FUNCTIONS
   Inherited from VkCallbackObject
          callCallbacks()  className(), addCallback(),  removeCallback(),
          removeAllCallbacks(), hasCallbacks(),  cloneCallbacks(),
          cloneCallback()


KNOWN DERIVED CLASSES
VIEWKIT 2.1 CHANGES
   Control Funtions
           virtual VkSubProcess run(VkScreen *screen);


          this additional API provides support for multi-screen
          applications...

CLASSES USED BY THIS CLASS
     VkSubProcess

BUGS
SEE ALSO
     VkCallbackObject, VkSubProcess
     ViewKit Programmer's Guide
     The X Window System, DEC Press, Bob Sheifler and Jim Gettys
     The X Window System Toolkit, DEC Press, Paul Asente and Ralph Swick
     The OSF/Motif Programmers Reference, Prentice Hall, OSF