qprocess_unix.cpp

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

	d->notifierStderr = new QSocketNotifier( sStderr[0], QSocketNotifier::Read );
	connect( d->notifierStderr, SIGNAL(activated(int)),
		this, SLOT(socketRead(int)) );
	if ( ioRedirection )
	    d->notifierStderr->setEnabled( TRUE );
    }

    // cleanup and return
    delete[] arglistQ;
    delete[] arglist;
    return TRUE;

error:
#if defined(QT_QPROCESS_DEBUG)
    qDebug( "QProcess::start(): error starting process" );
#endif
    if ( d->procManager )
	d->procManager->cleanup();
    if ( comms & Stdin ) {
	::close( sStdin[1] );
	::close( sStdin[0] );
    }
    if ( comms & Stdout ) {
	::close( sStdout[0] );
	::close( sStdout[1] );
    }
    if ( comms & Stderr ) {
	::close( sStderr[0] );
	::close( sStderr[1] );
    }
    ::close( fd[0] );
    ::close( fd[1] );
    delete[] arglistQ;
    delete[] arglist;
    return FALSE;
}


/*!
  Asks the process to terminate. Processes can ignore this wish. If you want to
  be sure that the process really terminates, you must use kill() instead.

  The slot returns immediately: it does not wait until the process has
  finished. When the process really exited, the signal processExited() is
  emitted.

  \sa kill() processExited()
*/
void QProcess::tryTerminate() const
{
    if ( d->proc != 0 )
	::kill( d->proc->pid, SIGTERM );
}

/*!
  Terminates the process. This is not a safe way to end a process since the
  process will not be able to do cleanup. tryTerminate() is a safer way to do
  it, but processes might ignore a tryTerminate().

  The nice way to end a process and to be sure that it is finished, is doing
  something like this:
  \code
    process->tryTerminate();
    QTimer::singleShot( 5000, process, SLOT( kill() ) );
  \endcode

  This tries to terminate the process the nice way. If the process is still
  running after 5 seconds, it terminates the process the hard way. The timeout
  should be chosen depending on the time the process needs to do all the
  cleanup: use a higher value if the process is likely to do heavy computation
  on cleanup.

  The slot returns immediately: it does not wait until the process has
  finished. When the process really exited, the signal processExited() is
  emitted.

  \sa tryTerminate() processExited()
*/
void QProcess::kill() const
{
    if ( d->proc != 0 )
	::kill( d->proc->pid, SIGKILL );
}

/*!
  Returns TRUE if the process is running, otherwise FALSE.

  \sa normalExit() exitStatus() processExited()
*/
bool QProcess::isRunning() const
{
    if ( d->exitValuesCalculated ) {
#if defined(QT_QPROCESS_DEBUG)
	qDebug( "QProcess::isRunning(): FALSE (already computed)" );
#endif
	return FALSE;
    }
    if ( d->proc == 0 )
	return FALSE;
    int status;
    if ( ::waitpid( d->proc->pid, &status, WNOHANG ) == d->proc->pid )
    {
	// compute the exit values
	QProcess *that = (QProcess*)this; // mutable
	that->exitNormal = WIFEXITED( status ) != 0;
	if ( exitNormal ) {
	    that->exitStat = (char)WEXITSTATUS( status );
	}
	d->exitValuesCalculated = TRUE;
#if defined(QT_QPROCESS_DEBUG)
	qDebug( "QProcess::isRunning() (PID: %d): FALSE", d->proc->pid );
#endif
	return FALSE;
    }
#if defined(QT_QPROCESS_DEBUG)
    qDebug( "QProcess::isRunning() (PID: %d): TRUE", d->proc->pid );
#endif
    return TRUE;
}

/*!
  Writes the data \a buf to the standard input of the process. The process may
  or may not read this data.

  This function returns immediately; the QProcess class might write the data at
  a later point (you have to enter the event loop for that). When all the data
  is written to the process, the signal wroteToStdin() is emitted. This does
  not mean that the process really read the data, since this class only detects
  when it was able to write the data to the operating system.

  \sa wroteToStdin() closeStdin() readStdout() readStderr()
*/
void QProcess::writeToStdin( const QByteArray& buf )
{
#if defined(QT_QPROCESS_DEBUG)
//    qDebug( "QProcess::writeToStdin(): write to stdin (%d)", d->socketStdin );
#endif
    d->stdinBuf.enqueue( new QByteArray(buf) );
    if ( d->notifierStdin != 0 )
	d->notifierStdin->setEnabled( TRUE );
}


/*!
  Closes standard input of the process.

  This function also deletes pending data that is not written to standard input
  yet.

  \sa wroteToStdin()
*/
void QProcess::closeStdin()
{
    if ( d->proc == 0 )
	return;
    if ( d->proc->socketStdin !=0 ) {
	while ( !d->stdinBuf.isEmpty() ) {
	    delete d->stdinBuf.dequeue();
	}
	delete d->notifierStdin;
	d->notifierStdin = 0;
	if ( ::close( d->proc->socketStdin ) != 0 ) {
	    qWarning( "Could not close stdin of child process" );
	}
#if defined(QT_QPROCESS_DEBUG)
	qDebug( "QProcess::closeStdin(): stdin (%d) closed", d->proc->socketStdin );
#endif
	d->proc->socketStdin = 0;
    }
}


/*
  This private slot is called when the process has outputted data to either
  standard output or standard error.
*/
void QProcess::socketRead( int fd )
{
    if ( d->socketReadCalled ) {
	// the slots that are connected to the readyRead...() signals might
	// trigger a recursive call of socketRead(). Avoid this since you get a
	// blocking read otherwise.
	return;
    }
#if defined(QT_QPROCESS_DEBUG)
    qDebug( "QProcess::socketRead(): %d", fd );
#endif
    if ( fd == 0 )
	return;
    const int bufsize = 4096;
    QByteArray *buffer = 0;
    uint oldSize;
    int n;
    if ( fd == d->proc->socketStdout ) {
	buffer = &d->bufStdout;
    } else if ( fd == d->proc->socketStderr ) {
	buffer = &d->bufStderr;
    } else {
	// this case should never happen, but just to be safe
	return;
    }

    // read data
    oldSize = buffer->size();
    buffer->resize( oldSize + bufsize );
    n = ::read( fd, buffer->data()+oldSize, bufsize );
    if ( n > 0 )
	buffer->resize( oldSize + n );
    else
	buffer->resize( oldSize );
    // eof or error?
    if ( n == 0 || n == -1 ) {
	if ( fd == d->proc->socketStdout ) {
#if defined(QT_QPROCESS_DEBUG)
	    qDebug( "QProcess::socketRead(): stdout (%d) closed", fd );
#endif
	    d->notifierStdout->setEnabled( FALSE );
	    delete d->notifierStdout;
	    d->notifierStdout = 0;
	    ::close( d->proc->socketStdout );
	    d->proc->socketStdout = 0;
	    return;
	} else if ( fd == d->proc->socketStderr ) {
#if defined(QT_QPROCESS_DEBUG)
	    qDebug( "QProcess::socketRead(): stderr (%d) closed", fd );
#endif
	    d->notifierStderr->setEnabled( FALSE );
	    delete d->notifierStderr;
	    d->notifierStderr = 0;
	    ::close( d->proc->socketStderr );
	    d->proc->socketStderr = 0;
	    return;
	}
    }
    // read all data that is available
    while ( n == bufsize ) {
	oldSize = buffer->size();
	buffer->resize( oldSize + bufsize );
	n = ::read( fd, buffer->data()+oldSize, bufsize );
	if ( n > 0 )
	    buffer->resize( oldSize + n );
	else
	    buffer->resize( oldSize );
    }

    d->socketReadCalled = TRUE;
    if ( fd == d->proc->socketStdout ) {
#if defined(QT_QPROCESS_DEBUG)
	qDebug( "QProcess::socketRead(): %d bytes read from stdout (%d)",
		buffer->size()-oldSize, fd );
#endif
	emit readyReadStdout();
    } else if ( fd == d->proc->socketStderr ) {
#if defined(QT_QPROCESS_DEBUG)
	qDebug( "QProcess::socketRead(): %d bytes read from stderr (%d)",
		buffer->size()-oldSize, fd );
#endif
	emit readyReadStderr();
    }
    d->socketReadCalled = FALSE;
}


/*
  This private slot is called when the process tries to write data to 
  standard input of the child process.
*/
void QProcess::socketWrite( int fd )
{
    if ( fd != d->proc->socketStdin || d->proc->socketStdin == 0 )
	return;
    if ( d->stdinBuf.isEmpty() ) {
	d->notifierStdin->setEnabled( FALSE );
	return;
    }
#if defined(QT_QPROCESS_DEBUG)
    qDebug( "QProcess::socketWrite(): write to stdin (%d)", fd );
#endif
    ssize_t ret = ::write( fd,
	    d->stdinBuf.head()->data() + d->stdinBufRead,
	    d->stdinBuf.head()->size() - d->stdinBufRead );
    if ( ret > 0 )
	d->stdinBufRead += ret;
    else if ( ret < 0 && errno == EPIPE ) {
	// turn off the socket notifier and discard the remaining data
	// because the pipe has been disconnected on the remote end.
	d->notifierStdin->setEnabled( FALSE );
	d->stdinBufRead = (ssize_t)d->stdinBuf.head()->size();
    }
    if ( d->stdinBufRead == (ssize_t)d->stdinBuf.head()->size() ) {
	d->stdinBufRead = 0;
	delete d->stdinBuf.dequeue();
	if ( wroteToStdinConnected && d->stdinBuf.isEmpty() )
	    emit wroteToStdin();
	socketWrite( fd );
    }
}

/*!
  \internal
  Flushes standard input. This is useful if you want to use QProcess in a
  synchronous manner.

  This function should probably go into the public API.
*/
void QProcess::flushStdin()
{
    socketWrite( d->proc->socketStdin );
}

/*
  This private slot is only used under Windows (but moc does not know about #if
  defined()).
*/
void QProcess::timeout()
{
}


/*
  This private function is used by connectNotify() and disconnectNotify() to
  change the value of ioRedirection (and related behaviour)
*/
void QProcess::setIoRedirection( bool value )
{
    ioRedirection = value;
    if ( ioRedirection ) {
	if ( d->notifierStdout )
	    d->notifierStdout->setEnabled( TRUE );
	if ( d->notifierStderr )
	    d->notifierStderr->setEnabled( TRUE );
    } else {
	if ( d->notifierStdout )
	    d->notifierStdout->setEnabled( FALSE );
	if ( d->notifierStderr )
	    d->notifierStderr->setEnabled( FALSE );
    }
}

/*
  This private function is used by connectNotify() and
  disconnectNotify() to change the value of notifyOnExit (and related
  behaviour)
*/
void QProcess::setNotifyOnExit( bool value )
{
    notifyOnExit = value;
}

/*
  This private function is used by connectNotify() and disconnectNotify() to
  change the value of wroteToStdinConnected (and related behaviour)
*/
void QProcess::setWroteStdinConnected( bool value )
{
    wroteToStdinConnected = value;
}

/*! \enum QProcess::PID
  \internal
*/
/*!
  Returns platform dependent information about the process. This can be used
  together with platform specific system calls.

  Under Unix the return value is the PID of the process, or -1 if no process is
  belonging to this object.

  Under Windows it is a pointer to the \c PROCESS_INFORMATION struct, or 0 if
  no process is belonging to this object.
*/
QProcess::PID QProcess::processIdentifier()
{
    if ( d->proc == 0 )
	return -1;
    return d->proc->pid;
}

int QProcess::priority() const
{
    if ( d->proc )
	return getpriority(PRIO_PROCESS,d->proc->pid);
    return 0;
}

/*!
  Sets the process priority to \a p, a value from -20 to 20,
  where 0 is normal, lower values a give more favourable
  priority, larger values less favourable.
*/
void QProcess::setPriority(int p)
{
    if ( d->proc )
	setpriority(PRIO_PROCESS,d->proc->pid,p);
}


#endif // QT_NO_PROCESS