/****************************************************************************

**

** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtCore module of the Qt Toolkit.

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** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

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**

** In addition, as a special exception, Nokia gives you certain additional

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****************************************************************************/

//#define QPROCESS_DEBUG

#if defined QPROCESS_DEBUG

#include <qdebug.h>

#include <qstring.h>

#include <ctype.h>

#if !defined(Q_OS_WINCE)

#include <errno.h>

#endif

QT_BEGIN_NAMESPACE

/*

    Returns a human readable representation of the first \a len

    characters in \a data.

*/

static QByteArray qt_prettyDebug(const char *data, int len, int maxSize)

{

    if (!data) return "(null)";

    QByteArray out;

    for (int i = 0; i < len && i < maxSize; ++i) {

        char c = data[i];

        if (isprint(c)) {

            out += c;

        } else switch (c) {

        case '\n': out += "\\n"; break;

        case '\r': out += "\\r"; break;

        case '\t': out += "\\t"; break;

        default:

            char buf[5];

            qsnprintf(buf, sizeof(buf), "\\%3o", c);

            buf[4] = '\0';

            out += QByteArray(buf);

        }

    }

    if (len < maxSize)

        out += "...";

    return out;

}

QT_END_NAMESPACE

#endif

#include "qprocess.h"

#include "qprocess_p.h"

#include <qbytearray.h>

#include <qdatetime.h>

#include <qcoreapplication.h>

#include <qsocketnotifier.h>

#include <qtimer.h>

#ifdef Q_WS_WIN

#include <private/qwineventnotifier_p.h>

#endif

#ifndef QT_NO_PROCESS

QT_BEGIN_NAMESPACE

void QProcessPrivate::Channel::clear()

{

    switch (type) {

    case PipeSource:

        Q_ASSERT(process);

        process->stdinChannel.type = Normal;

        process->stdinChannel.process = 0;

        break;

    case PipeSink:

        Q_ASSERT(process);

        process->stdoutChannel.type = Normal;

        process->stdoutChannel.process = 0;

        break;

    }

    type = Normal;

    file.clear();

    process = 0;

}

/*!

    \class QProcess

    \brief The QProcess class is used to start external programs and

    to communicate with them.

    \ingroup io

    \ingroup misc

    \mainclass

    \reentrant

    To start a process, pass the name and command line arguments of

    the program you want to run as arguments to start(). For example:

    \snippet doc/src/snippets/qprocess/qprocess-simpleexecution.cpp 0

    \dots

    \snippet doc/src/snippets/qprocess/qprocess-simpleexecution.cpp 1

    \snippet doc/src/snippets/qprocess/qprocess-simpleexecution.cpp 2

    QProcess then enters the \l Starting state, and when the program

    has started, QProcess enters the \l Running state and emits

    started().

    QProcess allows you to treat a process as a sequential I/O

    device. You can write to and read from the process just as you

    would access a network connection using QTcpSocket. You can then

    write to the process's standard input by calling write(), and

    read the standard output by calling read(), readLine(), and

    getChar(). Because it inherits QIODevice, QProcess can also be

    used as an input source for QXmlReader, or for generating data to

    be uploaded using QFtp.

    \note On Windows CE, reading and writing to a process is not supported.

    When the process exits, QProcess reenters the \l NotRunning state

    (the initial state), and emits finished().

    The finished() signal provides the exit code and exit status of

    the process as arguments, and you can also call exitCode() to

    obtain the exit code of the last process that finished, and

    exitStatus() to obtain its exit status. If an error occurs at

    any point in time, QProcess will emit the error() signal. You

    can also call error() to find the type of error that occurred

    last, and state() to find the current process state.

    \section1 Communicating via Channels

    Processes have two predefined output channels: The standard

    output channel (\c stdout) supplies regular console output, and

    the standard error channel (\c stderr) usually supplies the

    errors that are printed by the process. These channels represent

    two separate streams of data. You can toggle between them by

    calling setReadChannel(). QProcess emits readyRead() when data is

    available on the current read channel. It also emits

    readyReadStandardOutput() when new standard output data is

    available, and when new standard error data is available,

    readyReadStandardError() is emitted. Instead of calling read(),

    readLine(), or getChar(), you can explicitly read all data from

    either of the two channels by calling readAllStandardOutput() or

    readAllStandardError().

    The terminology for the channels can be misleading. Be aware that

    the process's output channels correspond to QProcess's

    \e read channels, whereas the process's input channels correspond

    to QProcess's \e write channels. This is because what we read

    using QProcess is the process's output, and what we write becomes

    the process's input.

    QProcess can merge the two output channels, so that standard

    output and standard error data from the running process both use

    the standard output channel. Call setProcessChannelMode() with

    MergedChannels before starting the process to activative

    this feature. You also have the option of forwarding the output of

    the running process to the calling, main process, by passing

    ForwardedChannels as the argument.

    Certain processes need special environment settings in order to

    operate. You can set environment variables for your process by

    calling setEnvironment(). To set a working directory, call

    setWorkingDirectory(). By default, processes are run in the

    current working directory of the calling process.

    \section1 Synchronous Process API

    QProcess provides a set of functions which allow it to be used

    without an event loop, by suspending the calling thread until

    certain signals are emitted:

    \list

    \o waitForStarted() blocks until the process has started.

    \o waitForReadyRead() blocks until new data is

    available for reading on the current read channel.

    \o waitForBytesWritten() blocks until one payload of

    data has been written to the process.

    \o waitForFinished() blocks until the process has finished.

    \endlist

    Calling these functions from the main thread (the thread that

    calls QApplication::exec()) may cause your user interface to

    freeze.

    The following example runs \c gzip to compress the string "Qt

    rocks!", without an event loop:

    \snippet doc/src/snippets/process/process.cpp 0

    \section1 Notes for Windows Users 

    Some Windows commands (for example, \c dir) are not provided by

    separate applications, but by the command interpreter itself.

    If you attempt to use QProcess to execute these commands directly,

    it won't work. One possible solution is to execute the command

    interpreter itself (\c{cmd.exe} on some Windows systems), and ask

    the interpreter to execute the desired command.

    \sa QBuffer, QFile, QTcpSocket

*/

/*!

    \enum QProcess::ProcessChannel

    This enum describes the process channels used by the running process.

    Pass one of these values to setReadChannel() to set the

    current read channel of QProcess.

    \value StandardOutput The standard output (stdout) of the running

           process.

    \value StandardError The standard error (stderr) of the running

           process.

    \sa setReadChannel()

*/

/*!

    \enum QProcess::ProcessChannelMode

    This enum describes the process channel modes of QProcess. Pass

    one of these values to setProcessChannelMode() to set the

    current read channel mode.

    \value SeparateChannels QProcess manages the output of the

    running process, keeping standard output and standard error data

    in separate internal buffers. You can select the QProcess's

    current read channel by calling setReadChannel(). This is the

    default channel mode of QProcess.

    \value MergedChannels QProcess merges the output of the running

    process into the standard output channel (\c stdout). The

    standard error channel (\c stderr) will not receive any data. The

    standard output and standard error data of the running process

    are interleaved.

    \value ForwardedChannels QProcess forwards the output of the

    running process onto the main process. Anything the child process

    writes to its standard output and standard error will be written

    to the standard output and standard error of the main process.

    \sa setReadChannelMode()

*/

/*!

    \enum QProcess::ProcessError

    This enum describes the different types of errors that are

    reported by QProcess.

    \value FailedToStart The process failed to start. Either the

    invoked program is missing, or you may have insufficient

    permissions to invoke the program.

    \value Crashed The process crashed some time after starting

    successfully.

    \value Timedout The last waitFor...() function timed out. The

    state of QProcess is unchanged, and you can try calling

    waitFor...() again.

    \value WriteError An error occurred when attempting to write to the

    process. For example, the process may not be running, or it may

    have closed its input channel.

    \value ReadError An error occurred when attempting to read from

    the process. For example, the process may not be running.

    \value UnknownError An unknown error occurred. This is the default

    return value of error().

    \sa error()

*/

/*!

    \enum QProcess::ProcessState

    This enum describes the different states of QProcess.

    \value NotRunning The process is not running.

    \value Starting The process is starting, but the program has not

    yet been invoked.

    \value Running The process is running and is ready for reading and

    writing.

    \sa state()

*/

/*!

    \enum QProcess::ExitStatus

    This enum describes the different exit statuses of QProcess.

    \value NormalExit The process exited normally.

    \value CrashExit The process crashed.

    \sa exitStatus()

*/

/*!

    \fn void QProcess::error(QProcess::ProcessError error)

    This signal is emitted when an error occurs with the process. The

    specified \a error describes the type of error that occurred.

*/

/*!

    \fn void QProcess::started()

    This signal is emitted by QProcess when the process has started,

    and state() returns \l Running.

*/

/*!

    \fn void QProcess::stateChanged(QProcess::ProcessState newState)

    This signal is emitted whenever the state of QProcess changes. The

    \a newState argument is the state QProcess changed to.

*/

/*!

    \fn void QProcess::finished(int exitCode)

    \obsolete

    \overload

    Use finished(int exitCode, QProcess::ExitStatus status) instead.

*/

/*!

    \fn void QProcess::finished(int exitCode, QProcess::ExitStatus exitStatus)

    This signal is emitted when the process finishes. \a exitCode is the exit

    code of the process, and \a exitStatus is the exit status.  After the

    process has finished, the buffers in QProcess are still intact. You can

    still read any data that the process may have written before it finished.

    \sa exitStatus()

*/

/*!

    \fn void QProcess::readyReadStandardOutput()

    This signal is emitted when the process has made new data

    available through its standard output channel (\c stdout). It is

    emitted regardless of the current \l{readChannel()}{read channel}.

    \sa readAllStandardOutput(), readChannel()

*/

/*!

    \fn void QProcess::readyReadStandardError()

    This signal is emitted when the process has made new data

    available through its standard error channel (\c stderr). It is

    emitted regardless of the current \l{readChannel()}{read

    channel}.

    \sa readAllStandardError(), readChannel()

*/

/*! \internal

*/

QProcessPrivate::QProcessPrivate()

{

    processChannel = QProcess::StandardOutput;

    processChannelMode = QProcess::SeparateChannels;

    processError = QProcess::UnknownError;

    processState = QProcess::NotRunning;

    pid = 0;

    sequenceNumber = 0;

    exitCode = 0;

    exitStatus = QProcess::NormalExit;

    startupSocketNotifier = 0;

    deathNotifier = 0;

    notifier = 0;

    pipeWriter = 0;

    childStartedPipe[0] = INVALID_Q_PIPE;

    childStartedPipe[1] = INVALID_Q_PIPE;

    deathPipe[0] = INVALID_Q_PIPE;

    deathPipe[1] = INVALID_Q_PIPE;

    exitCode = 0;

    crashed = false;

    dying = false;

    emittedReadyRead = false;

    emittedBytesWritten = false;

#ifdef Q_WS_WIN

    pipeWriter = 0;

    processFinishedNotifier = 0;

#endif // Q_WS_WIN

#ifdef Q_OS_UNIX

    serial = 0;

#endif

}

/*! \internal

*/

QProcessPrivate::~QProcessPrivate()

{

    if (stdinChannel.process)

        stdinChannel.process->stdoutChannel.clear();

    if (stdoutChannel.process)

        stdoutChannel.process->stdinChannel.clear();

}

/*! \internal

*/

void QProcessPrivate::cleanup()

{

    q_func()->setProcessState(QProcess::NotRunning);

#ifdef Q_OS_WIN

    if (pid) {

        CloseHandle(pid->hThread);

        CloseHandle(pid->hProcess);

        delete pid;

        pid = 0;

    }

    if (processFinishedNotifier) {

        processFinishedNotifier->setEnabled(false);

        qDeleteInEventHandler(processFinishedNotifier);

        processFinishedNotifier = 0;

    }

#endif

    pid = 0;

    sequenceNumber = 0;

    dying = false;

    if (stdoutChannel.notifier) {

        stdoutChannel.notifier->setEnabled(false);

        qDeleteInEventHandler(stdoutChannel.notifier);

        stdoutChannel.notifier = 0;

    }

    if (stderrChannel.notifier) {

        stderrChannel.notifier->setEnabled(false);

        qDeleteInEventHandler(stderrChannel.notifier);

        stderrChannel.notifier = 0;

    }

    if (stdinChannel.notifier) {

        stdinChannel.notifier->setEnabled(false);

        qDeleteInEventHandler(stdinChannel.notifier);

        stdinChannel.notifier = 0;

    }

    if (startupSocketNotifier) {

        startupSocketNotifier->setEnabled(false);

        qDeleteInEventHandler(startupSocketNotifier);

        startupSocketNotifier = 0;

    }

    if (deathNotifier) {

        deathNotifier->setEnabled(false);

        qDeleteInEventHandler(deathNotifier);

        deathNotifier = 0;

    }

    if (notifier) {

        qDeleteInEventHandler(notifier);

        notifier = 0;

    }

    destroyPipe(stdoutChannel.pipe);

    destroyPipe(stderrChannel.pipe);

    destroyPipe(stdinChannel.pipe);

    destroyPipe(childStartedPipe);

    destroyPipe(deathPipe);

#ifdef Q_OS_UNIX

    serial = 0;

#endif

}

/*! \internal

*/

bool QProcessPrivate::_q_canReadStandardOutput()

{

    Q_Q(QProcess);

    qint64 available = bytesAvailableFromStdout();

    if (available == 0) {

        if (stdoutChannel.notifier)

            stdoutChannel.notifier->setEnabled(false);

        destroyPipe(stdoutChannel.pipe);

#if defined QPROCESS_DEBUG

        qDebug("QProcessPrivate::canReadStandardOutput(), 0 bytes available");

#endif

        return false;

    }

    char *ptr = outputReadBuffer.reserve(available);

    qint64 readBytes = readFromStdout(ptr, available);

    if (readBytes == -1) {

        processError = QProcess::ReadError;

        q->setErrorString(QProcess::tr("Error reading from process"));

        emit q->error(processError);

#if defined QPROCESS_DEBUG

        qDebug("QProcessPrivate::canReadStandardOutput(), failed to read from the process");

#endif

        return false;

    }

#if defined QPROCESS_DEBUG

    qDebug("QProcessPrivate::canReadStandardOutput(), read %d bytes from the process' output",

            int(readBytes));

#endif

    if (stdoutChannel.closed) {

        outputReadBuffer.chop(readBytes);

        return false;

    }

    outputReadBuffer.chop(available - readBytes);

    bool didRead = false;

    if (readBytes == 0) {

        if (stdoutChannel.notifier)

            stdoutChannel.notifier->setEnabled(false);

    } else if (processChannel == QProcess::StandardOutput) {

        didRead = true;

        if (!emittedReadyRead) {

            emittedReadyRead = true;

            emit q->readyRead();

            emittedReadyRead = false;

        }

    }

    emit q->readyReadStandardOutput();

    return didRead;

}

/*! \internal

*/

bool QProcessPrivate::_q_canReadStandardError()

{

    Q_Q(QProcess);

    qint64 available = bytesAvailableFromStderr();

    if (available == 0) {

        if (stderrChannel.notifier)

            stderrChannel.notifier->setEnabled(false);

        destroyPipe(stderrChannel.pipe);

        return false;

    }

    char *ptr = errorReadBuffer.reserve(available);

    qint64 readBytes = readFromStderr(ptr, available);

    if (readBytes == -1) {

        processError = QProcess::ReadError;

        q->setErrorString(QProcess::tr("Error reading from process"));

        emit q->error(processError);

        return false;

    }

    if (stderrChannel.closed) {

        errorReadBuffer.chop(readBytes);

        return false;

    }

    errorReadBuffer.chop(available - readBytes);

    bool didRead = false;

    if (readBytes == 0) {

        if (stderrChannel.notifier)

            stderrChannel.notifier->setEnabled(false);

    } else if (processChannel == QProcess::StandardError) {

        didRead = true;

        if (!emittedReadyRead) {

            emittedReadyRead = true;

            emit q->readyRead();

            emittedReadyRead = false;

        }

    }

    emit q->readyReadStandardError();

    return didRead;

}

/*! \internal

*/

bool QProcessPrivate::_q_canWrite()

{

    Q_Q(QProcess);

    if (stdinChannel.notifier)

        stdinChannel.notifier->setEnabled(false);

    if (writeBuffer.isEmpty()) {

#if defined QPROCESS_DEBUG

        qDebug("QProcessPrivate::canWrite(), not writing anything (empty write buffer).");

#endif

        return false;

    }

    qint64 written = writeToStdin(writeBuffer.readPointer(),

                                      writeBuffer.nextDataBlockSize());

    if (written < 0) {

        destroyPipe(stdinChannel.pipe);

        processError = QProcess::WriteError;

        q->setErrorString(QProcess::tr("Error writing to process"));

#if defined(QPROCESS_DEBUG) && !defined(Q_OS_WINCE)

        qDebug("QProcessPrivate::canWrite(), failed to write (%s)", strerror(errno));

#endif

        emit q->error(processError);

        return false;

    }

#if defined QPROCESS_DEBUG

    qDebug("QProcessPrivate::canWrite(), wrote %d bytes to the process input", int(written));

#endif

    writeBuffer.free(written);

    if (!emittedBytesWritten) {

        emittedBytesWritten = true;

        emit q->bytesWritten(written);

        emittedBytesWritten = false;

    }

    if (stdinChannel.notifier && !writeBuffer.isEmpty())

        stdinChannel.notifier->setEnabled(true);

    if (writeBuffer.isEmpty() && stdinChannel.closed)

        closeWriteChannel();

    return true;

}

/*! \internal

*/

bool QProcessPrivate::_q_processDied()

{

    Q_Q(QProcess);

#if defined QPROCESS_DEBUG

    qDebug("QProcessPrivate::_q_processDied()");

#endif

#ifdef Q_OS_UNIX

    if (!waitForDeadChild())

        return false;

#endif

#ifdef Q_OS_WIN

    if (processFinishedNotifier)

        processFinishedNotifier->setEnabled(false);

#endif

    // the process may have died before it got a chance to report that it was

    // either running or stopped, so we will call _q_startupNotification() and

    // give it a chance to emit started() or error(FailedToStart).

    if (processState == QProcess::Starting) {

        if (!_q_startupNotification())

            return true;

    }

    if (dying) {

        // at this point we know the process is dead. prevent

        // reentering this slot recursively by calling waitForFinished()

        // or opening a dialog inside slots connected to the readyRead

        // signals emitted below.

        return true;

    }

    dying = true;

    // in case there is data in the pipe line and this slot by chance

    // got called before the read notifications, call these two slots

    // so the data is made available before the process dies.

    _q_canReadStandardOutput();

    _q_canReadStandardError();

    findExitCode();

    if (crashed) {

        exitStatus = QProcess::CrashExit;

        processError = QProcess::Crashed;

        q->setErrorString(QProcess::tr("Process crashed"));

        emit q->error(processError);

    }

    bool wasRunning = (processState == QProcess::Running);

    cleanup();

    if (wasRunning) {

        // we received EOF now:

        emit q->readChannelFinished();

        // in the future:

        //emit q->standardOutputClosed();

        //emit q->standardErrorClosed();

        emit q->finished(exitCode);

        emit q->finished(exitCode, exitStatus);

    }

#if defined QPROCESS_DEBUG

    qDebug("QProcessPrivate::_q_processDied() process is dead");

#endif

    return true;

}

/*! \internal

*/

bool QProcessPrivate::_q_startupNotification()

{

    Q_Q(QProcess);

#if defined QPROCESS_DEBUG

    qDebug("QProcessPrivate::startupNotification()");

#endif

    if (startupSocketNotifier)

        startupSocketNotifier->setEnabled(false);

    if (processStarted()) {

        q->setProcessState(QProcess::Running);

        emit q->started();

        return true;

    }

    q->setProcessState(QProcess::NotRunning);

    processError = QProcess::FailedToStart;

    emit q->error(processError);

#ifdef Q_OS_UNIX

    // make sure the process manager removes this entry

    waitForDeadChild();

    findExitCode();

#endif

    cleanup();

    return false;

}

/*! \internal

*/

void QProcessPrivate::closeWriteChannel()

{

#if defined QPROCESS_DEBUG

    qDebug("QProcessPrivate::closeWriteChannel()");

#endif

    if (stdinChannel.notifier) {

        extern void qDeleteInEventHandler(QObject *o);

        stdinChannel.notifier->setEnabled(false);

        if (stdinChannel.notifier) {

            qDeleteInEventHandler(stdinChannel.notifier);

            stdinChannel.notifier = 0;

        } 

    }

#ifdef Q_OS_WIN

    // ### Find a better fix, feeding the process little by little

    // instead.

    flushPipeWriter();

#endif

    destroyPipe(stdinChannel.pipe);

}

/*!

    Constructs a QProcess object with the given \a parent.

*/

QProcess::QProcess(QObject *parent)

    : QIODevice(*new QProcessPrivate, parent)

{

#if defined QPROCESS_DEBUG

    qDebug("QProcess::QProcess(%p)", parent);

#endif

}

/*!

    Destructs the QProcess object, i.e., killing the process.

    Note that this function will not return until the process is

    terminated.

*/

QProcess::~QProcess()

{

    Q_D(QProcess);

    if (d->processState != NotRunning) {

        qWarning("QProcess: Destroyed while process is still running.");

        kill();

        waitForFinished();

    }

#ifdef Q_OS_UNIX

    // make sure the process manager removes this entry

    d->findExitCode();

#endif

    d->cleanup();

}

/*!

    \obsolete

    Returns the read channel mode of the QProcess. This function is

    equivalent to processChannelMode()

    \sa processChannelMode()

*/

QProcess::ProcessChannelMode QProcess::readChannelMode() const

{

    return processChannelMode();

}

/*!

    \obsolete

    Use setProcessChannelMode(\a mode) instead.

    \sa setProcessChannelMode()

*/

void QProcess::setReadChannelMode(ProcessChannelMode mode)

{

    setProcessChannelMode(mode);

}

/*!

    \since 4.2

    Returns the channel mode of the QProcess standard output and

    standard error channels.

    \sa setReadChannelMode(), ProcessChannelMode, setReadChannel()

*/

QProcess::ProcessChannelMode QProcess::processChannelMode() const

{

    Q_D(const QProcess);

    return d->processChannelMode;

}

/*!

    \since 4.2

    Sets the channel mode of the QProcess standard output and standard

    error channels to the \a mode specified.

    This mode will be used the next time start() is called. For example:

    \snippet doc/src/snippets/code/src_corelib_io_qprocess.cpp 0

    \sa readChannelMode(), ProcessChannelMode, setReadChannel()

*/

void QProcess::setProcessChannelMode(ProcessChannelMode mode)

{

    Q_D(QProcess);

    d->processChannelMode = mode;

}

/*!

    Returns the current read channel of the QProcess.

    \sa setReadChannel()

*/

QProcess::ProcessChannel QProcess::readChannel() const

{

    Q_D(const QProcess);

    return d->processChannel;

}

/*!

    Sets the current read channel of the QProcess to the given \a

    channel. The current input channel is used by the functions

    read(), readAll(), readLine(), and getChar(). It also determines

    which channel triggers QProcess to emit readyRead().

    \sa readChannel()

*/

void QProcess::setReadChannel(ProcessChannel channel)

{

    Q_D(QProcess);

    if (d->processChannel != channel) {

        QByteArray buf = d->buffer.readAll();

        if (d->processChannel == QProcess::StandardOutput) {

            for (int i = buf.size() - 1; i >= 0; --i)

                d->outputReadBuffer.ungetChar(buf.at(i));

        } else {

            for (int i = buf.size() - 1; i >= 0; --i)

                d->errorReadBuffer.ungetChar(buf.at(i));

        }

    }

    d->processChannel = channel;

}

/*!

    Closes the read channel \a channel. After calling this function,

    QProcess will no longer receive data on the channel. Any data that

    has already been received is still available for reading.

    Call this function to save memory, if you are not interested in

    the output of the process.

    \sa closeWriteChannel(), setReadChannel()

*/

void QProcess::closeReadChannel(ProcessChannel channel)

{

    Q_D(QProcess);

    if (channel == StandardOutput)

        d->stdoutChannel.closed = true;

    else

        d->stderrChannel.closed = true;

}

/*!

    Schedules the write channel of QProcess to be closed. The channel

    will close once all data has been written to the process. After

    calling this function, any attempts to write to the process will

    fail.

    Closing the write channel is necessary for programs that read

    input data until the channel has been closed. For example, the

    program "more" is used to display text data in a console on both

    Unix and Windows. But it will not display the text data until

    QProcess's write channel has been closed. Example:

    \snippet doc/src/snippets/code/src_corelib_io_qprocess.cpp 1

    The write channel is implicitly opened when start() is called.

    \sa closeReadChannel()

*/

void QProcess::closeWriteChannel()

{

    Q_D(QProcess);

    d->stdinChannel.closed = true; // closing

    if (d->writeBuffer.isEmpty())

        d->closeWriteChannel();

}

/*!

    \since 4.2

    Redirects the process' standard input to the file indicated by \a

    fileName. When an input redirection is in place, the QProcess

    object will be in read-only mode (calling write() will result in

    error).

    If the file \a fileName does not exist at the moment start() is

    called or is not readable, starting the process will fail.

    Calling setStandardInputFile() after the process has started has no

    effect.

    \sa setStandardOutputFile(), setStandardErrorFile(),

        setStandardOutputProcess()

*/

void QProcess::setStandardInputFile(const QString &fileName)

{

    Q_D(QProcess);

    d->stdinChannel = fileName;

}

/*!

    \since 4.2

    Redirects the process' standard output to the file \a

    fileName. When the redirection is in place, the standard output

    read channel is closed: reading from it using read() will always

    fail, as will readAllStandardOutput().

    If the file \a fileName doesn't exist at the moment start() is

    called, it will be created. If it cannot be created, the starting

    will fail.

    If the file exists and \a mode is QIODevice::Truncate, the file

    will be truncated. Otherwise (if \a mode is QIODevice::Append),

    the file will be appended to.

    Calling setStandardOutputFile() after the process has started has

    no effect.

    \sa setStandardInputFile(), setStandardErrorFile(),

        setStandardOutputProcess()

*/

void QProcess::setStandardOutputFile(const QString &fileName, OpenMode mode)

{

    Q_ASSERT(mode == Append || mode == Truncate);

    Q_D(QProcess);

    d->stdoutChannel = fileName;

    d->stdoutChannel.append = mode == Append;

}

/*!

    \since 4.2

    Redirects the process' standard error to the file \a

    fileName. When the redirection is in place, the standard error

    read channel is closed: reading from it using read() will always

    fail, as will readAllStandardError(). The file will be appended to

    if \a mode is Append, otherwise, it will be truncated.

    See setStandardOutputFile() for more information on how the file

    is opened.

    Note: if setProcessChannelMode() was called with an argument of

    QProcess::MergedChannels, this function has no effect.

    \sa setStandardInputFile(), setStandardOutputFile(),

        setStandardOutputProcess()

*/

void QProcess::setStandardErrorFile(const QString &fileName, OpenMode mode)

{

    Q_ASSERT(mode == Append || mode == Truncate);

    Q_D(QProcess);

    d->stderrChannel = fileName;

    d->stderrChannel.append = mode == Append;

}

/*!

    \since 4.2

    Pipes the standard output stream of this process to the \a

    destination process' standard input.

    The following shell command:

    \snippet doc/src/snippets/code/src_corelib_io_qprocess.cpp 2

    Can be accomplished with QProcesses with the following code:

    \snippet doc/src/snippets/code/src_corelib_io_qprocess.cpp 3

*/

void QProcess::setStandardOutputProcess(QProcess *destination)

{

    QProcessPrivate *dfrom = d_func();

    QProcessPrivate *dto = destination->d_func();

    dfrom->stdoutChannel.pipeTo(dto);

    dto->stdinChannel.pipeFrom(dfrom);

}

/*!

    If QProcess has been assigned a working directory, this function returns

    the working directory that the QProcess will enter before the program has

    started. Otherwise, (i.e., no directory has been assigned,) an empty

    string is returned, and QProcess will use the application's current

    working directory instead.

    \sa setWorkingDirectory()

*/

QString QProcess::workingDirectory() const

{

    Q_D(const QProcess);

    return d->workingDirectory;

}

/*!

    Sets the working directory to \a dir. QProcess will start the

    process in this directory. The default behavior is to start the

    process in the working directory of the calling process.

    \sa workingDirectory(), start()

*/

void QProcess::setWorkingDirectory(const QString &dir)

{

    Q_D(QProcess);

    d->workingDirectory = dir;

}

/*!

    Returns the native process identifier for the running process, if

    available.  If no process is currently running, 0 is returned.

*/

Q_PID QProcess::pid() const

{

    Q_D(const QProcess);

    return d->pid;

}

/*! \reimp

    This function operates on the current read channel.

    \sa readChannel(), setReadChannel()

*/

bool QProcess::canReadLine() const

{

    Q_D(const QProcess);

    const QRingBuffer *readBuffer = (d->processChannel == QProcess::StandardError)

                                    ? &d->errorReadBuffer

                                    : &d->outputReadBuffer;

    return readBuffer->canReadLine() || QIODevice::canReadLine();

}

/*!

    Closes all communication with the process and kills it. After calling this

    function, QProcess will no longer emit readyRead(), and data can no

    longer be read or written.

*/

void QProcess::close()

{

    emit aboutToClose();

    while (waitForBytesWritten(-1))

        ;

    kill();

    waitForFinished(-1);

    QIODevice::close();

}

/*! \reimp

   Returns true if the process is not running, and no more data is available

   for reading; otherwise returns false.

*/

bool QProcess::atEnd() const

{

    Q_D(const QProcess);

    const QRingBuffer *readBuffer = (d->processChannel == QProcess::StandardError)

                                    ? &d->errorReadBuffer

                                    : &d->outputReadBuffer;

    return QIODevice::atEnd() && (!isOpen() || readBuffer->isEmpty());

}

/*! \reimp

*/

bool QProcess::isSequential() const

{

    return true;

}

/*! \reimp

*/

qint64 QProcess::bytesAvailable() const

{

    Q_D(const QProcess);

    const QRingBuffer *readBuffer = (d->processChannel == QProcess::StandardError)

                                    ? &d->errorReadBuffer

                                    : &d->outputReadBuffer;

#if defined QPROCESS_DEBUG

    qDebug("QProcess::bytesAvailable() == %i (%s)", readBuffer->size(),

           (d->processChannel == QProcess::StandardError) ? "stderr" : "stdout");

#endif

    return readBuffer->size() + QIODevice::bytesAvailable();

}

/*! \reimp

*/

qint64 QProcess::bytesToWrite() const

{

    Q_D(const QProcess);

    qint64 size = d->writeBuffer.size();

#ifdef Q_OS_WIN

    size += d->pipeWriterBytesToWrite();

#endif

    return size;

}

/*!

    Returns the type of error that occurred last.

    \sa state()

*/

QProcess::ProcessError QProcess::error() const

{

    Q_D(const QProcess);

    return d->processError;

}

/*!

    Returns the current state of the process.

    \sa stateChanged(), error()

*/

QProcess::ProcessState QProcess::state() const

{

    Q_D(const QProcess);

    return d->processState;

}

/*!

    Sets the environment that QProcess will use when starting a process to the

    \a environment specified which consists of a list of key=value pairs.

    For example, the following code adds the \c{C:\\BIN} directory to the list of

    executable paths (\c{PATHS}) on Windows:

    \snippet doc/src/snippets/qprocess-environment/main.cpp 0

    \sa environment(), systemEnvironment()

*/

void QProcess::setEnvironment(const QStringList &environment)

{

    Q_D(QProcess);

    d->environment = environment;

}

/*!

    Returns the environment that QProcess will use when starting a

    process, or an empty QStringList if no environment has been set

    using setEnvironment(). If no environment has been set, the

    environment of the calling process will be used.

    \note The environment settings are ignored on Windows CE,

    as there is no concept of an environment.

    \sa setEnvironment(), systemEnvironment()

*/

QStringList QProcess::environment() const

{

    Q_D(const QProcess);

    return d->environment;

}

/*!

    Blocks until the process has started and the started() signal has

    been emitted, or until \a msecs milliseconds have passed.

    Returns true if the process was started successfully; otherwise

    returns false (if the operation timed out or if an error

    occurred).

    This function can operate without an event loop. It is

    useful when writing non-GUI applications and when performing

    I/O operations in a non-GUI thread.

    \warning Calling this function from the main (GUI) thread

    might cause your user interface to freeze.

    If msecs is -1, this function will not time out.

    \sa started(), waitForReadyRead(), waitForBytesWritten(), waitForFinished()

*/

bool QProcess::waitForStarted(int msecs)

{

    Q_D(QProcess);

    if (d->processState == QProcess::Starting) {

        if (!d->waitForStarted(msecs))

            return false;

        setProcessState(QProcess::Running);

        emit started();

    }

    return d->processState == QProcess::Running;

}

/*! \reimp

*/

bool QProcess::waitForReadyRead(int msecs)

{

    Q_D(QProcess);

    if (d->processState == QProcess::NotRunning)

        return false;

    if (d->processChannel == QProcess::StandardOutput && d->stdoutChannel.closed)

        return false;

    if (d->processChannel == QProcess::StandardError && d->stderrChannel.closed)

        return false;

    return d->waitForReadyRead(msecs);

}

/*! \reimp

*/

bool QProcess::waitForBytesWritten(int msecs)

{

    Q_D(QProcess);

    if (d->processState == QProcess::NotRunning)

        return false;

    if (d->processState == QProcess::Starting) {

        QTime stopWatch;

        stopWatch.start();

        bool started = waitForStarted(msecs);

        if (!started)

            return false;

        if (msecs != -1)

            msecs -= stopWatch.elapsed();

    }

    return d->waitForBytesWritten(msecs);

}

/*!

    Blocks until the process has finished and the finished() signal

    has been emitted, or until \a msecs milliseconds have passed.

    Returns true if the process finished; otherwise returns false (if

    the operation timed out or if an error occurred).

    This function can operate without an event loop. It is

    useful when writing non-GUI applications and when performing

    I/O operations in a non-GUI thread.

    \warning Calling this function from the main (GUI) thread

    might cause your user interface to freeze.

    If msecs is -1, this function will not time out.

    \sa finished(), waitForStarted(), waitForReadyRead(), waitForBytesWritten()

*/

bool QProcess::waitForFinished(int msecs)

{

    Q_D(QProcess);

    if (d->processState == QProcess::NotRunning)

        return false;

    if (d->processState == QProcess::Starting) {

        QTime stopWatch;

        stopWatch.start();

        bool started = waitForStarted(msecs);

        if (!started)

            return false;

        if (msecs != -1)

            msecs -= stopWatch.elapsed();

    }

    return d->waitForFinished(msecs);

}

/*!

    Sets the current state of the QProcess to the \a state specified.

    \sa state()

*/

void QProcess::setProcessState(ProcessState state)

{

    Q_D(QProcess);

    if (d->processState == state)

        return;

    d->processState = state;

    emit stateChanged(state);

}

/*!

  This function is called in the child process context just before the

    program is executed on Unix or Mac OS X (i.e., after \e fork(), but before

    \e execve()). Reimplement this function to do last minute initialization

    of the child process. Example:

    \snippet doc/src/snippets/code/src_corelib_io_qprocess.cpp 4

    You cannot exit the process (by calling exit(), for instance) from

    this function. If you need to stop the program before it starts

    execution, your workaround is to emit finished() and then call

    exit().

    \warning This function is called by QProcess on Unix and Mac OS X

    only. On Windows, it is not called.

*/

void QProcess::setupChildProcess()

{

}

/*! \reimp

*/

qint64 QProcess::readData(char *data, qint64 maxlen)

{

    Q_D(QProcess);

    QRingBuffer *readBuffer = (d->processChannel == QProcess::StandardError)

                              ? &d->errorReadBuffer

                              : &d->outputReadBuffer;

    if (maxlen == 1 && !readBuffer->isEmpty()) {

        int c = readBuffer->getChar();

        if (c == -1) {

#if defined QPROCESS_DEBUG

            qDebug("QProcess::readData(%p \"%s\", %d) == -1",

                   data, qt_prettyDebug(data, 1, maxlen).constData(), 1);

#endif

            return -1;

        }

        *data = (char) c;

#if defined QPROCESS_DEBUG

        qDebug("QProcess::readData(%p \"%s\", %d) == 1",

               data, qt_prettyDebug(data, 1, maxlen).constData(), 1);

#endif

        return 1;

    }

    qint64 bytesToRead = qint64(qMin(readBuffer->size(), (int)maxlen));

    qint64 readSoFar = 0;

    while (readSoFar < bytesToRead) {

        const char *ptr = readBuffer->readPointer();

        int bytesToReadFromThisBlock = qMin<qint64>(bytesToRead - readSoFar,

                                            readBuffer->nextDataBlockSize());

        memcpy(data + readSoFar, ptr, bytesToReadFromThisBlock);

        readSoFar += bytesToReadFromThisBlock;

        readBuffer->free(bytesToReadFromThisBlock);

    }

#if defined QPROCESS_DEBUG

    qDebug("QProcess::readData(%p \"%s\", %lld) == %lld",

           data, qt_prettyDebug(data, readSoFar, 16).constData(), maxlen, readSoFar);

#endif

    if (!readSoFar && d->processState == QProcess::NotRunning)

        return -1;              // EOF

    return readSoFar;

}

/*! \reimp

*/

qint64 QProcess::writeData(const char *data, qint64 len)

{

    Q_D(QProcess);

#if defined(Q_OS_WINCE)

    Q_UNUSED(data);

    Q_UNUSED(len);

    d->processError = QProcess::WriteError;

    setErrorString(tr("Error writing to process"));

    emit error(d->processError);

    return -1;

#endif

    if (d->stdinChannel.closed) {

#if defined QPROCESS_DEBUG

    qDebug("QProcess::writeData(%p \"%s\", %lld) == 0 (write channel closing)",

           data, qt_prettyDebug(data, len, 16).constData(), len);

#endif

        return 0;

    }

    if (len == 1) {

        d->writeBuffer.putChar(*data);

        if (d->stdinChannel.notifier)

            d->stdinChannel.notifier->setEnabled(true);

#if defined QPROCESS_DEBUG

    qDebug("QProcess::writeData(%p \"%s\", %lld) == 1 (written to buffer)",

           data, qt_prettyDebug(data, len, 16).constData(), len);

#endif

        return 1;

    }

    char *dest = d->writeBuffer.reserve(len);

    memcpy(dest, data, len);

    if (d->stdinChannel.notifier)

        d->stdinChannel.notifier->setEnabled(true);

#if defined QPROCESS_DEBUG

    qDebug("QProcess::writeData(%p \"%s\", %lld) == %lld (written to buffer)",

           data, qt_prettyDebug(data, len, 16).constData(), len, len);

#endif

    return len;

}

/*!

    Regardless of the current read channel, this function returns all

    data available from the standard output of the process as a

    QByteArray.

    \sa readyReadStandardOutput(), readAllStandardError(), readChannel(), setReadChannel()

*/

QByteArray QProcess::readAllStandardOutput()

{

    ProcessChannel tmp = readChannel();

    setReadChannel(StandardOutput);

    QByteArray data = readAll();

    setReadChannel(tmp);

    return data;

}

/*!

    Regardless of the current read channel, this function returns all

    data available from the standard error of the process as a

    QByteArray.

    \sa readyReadStandardError(), readAllStandardOutput(), readChannel(), setReadChannel()

*/

QByteArray QProcess::readAllStandardError()

{

    ProcessChannel tmp = readChannel();

    setReadChannel(StandardError);

    QByteArray data = readAll();

    setReadChannel(tmp);

    return data;

}

/*!

    Starts the program \a program in a new process, if one is not already

    running, passing the command line arguments in \a arguments. The OpenMode

    is set to \a mode.

    The QProcess object will immediately enter the Starting state. If the

    process starts successfully, QProcess will emit started(); otherwise,

    error() will be emitted. If the QProcess object is already running a

    process, a warning may be printed at the console, and the existing

    process will continue running.

    Note that arguments that contain spaces are not passed to the

    process as separate arguments.

    \bold{Windows:} Arguments that contain spaces are wrapped in quotes.

    \note Processes are started asynchronously, which means the started()

    and error() signals may be delayed. Call waitForStarted() to make

    sure the process has started (or has failed to start) and those signals

    have been emitted.

    \sa pid(), started(), waitForStarted()

*/

void QProcess::start(const QString &program, const QStringList &arguments, OpenMode mode)

{

    Q_D(QProcess);

    if (d->processState != NotRunning) {

        qWarning("QProcess::start: Process is already running");

        return;

    }

#if defined QPROCESS_DEBUG

    qDebug() << "QProcess::start(" << program << "," << arguments << "," << mode << ")";

#endif

    d->outputReadBuffer.clear();

    d->errorReadBuffer.clear();

    if (d->stdinChannel.type != QProcessPrivate::Channel::Normal)

        mode &= ~WriteOnly;     // not open for writing

    if (d->stdoutChannel.type != QProcessPrivate::Channel::Normal &&

        (d->stderrChannel.type != QProcessPrivate::Channel::Normal ||

         d->processChannelMode == MergedChannels))

        mode &= ~ReadOnly;      // not open for reading

    if (mode == 0)

        mode = Unbuffered;

    QIODevice::open(mode);

    d->stdinChannel.closed = false;

    d->stdoutChannel.closed = false;

    d->stderrChannel.closed = false;

    d->program = program;

    d->arguments = arguments;

    d->exitCode = 0;

    d->exitStatus = NormalExit;

    d->processError = QProcess::UnknownError;

    d->errorString.clear();

    d->startProcess();

}

static QStringList parseCombinedArgString(const QString &program)

{

    QStringList args;

    QString tmp;

    int quoteCount = 0;

    bool inQuote = false;

    // handle quoting. tokens can be surrounded by double quotes

    // "hello world". three consecutive double quotes represent

    // the quote character itself.

    for (int i = 0; i < program.size(); ++i) {

        if (program.at(i) == QLatin1Char('"')) {

            ++quoteCount;

            if (quoteCount == 3) {

                // third consecutive quote

                quoteCount = 0;

                tmp += program.at(i);

            }

            continue;

        }

        if (quoteCount) {

            if (quoteCount == 1)

                inQuote = !inQuote;

            quoteCount = 0;

        }

        if (!inQuote && program.at(i).isSpace()) {

            if (!tmp.isEmpty()) {

                args += tmp;

                tmp.clear();

            }

        } else {

            tmp += program.at(i);

        }

    }

    if (!tmp.isEmpty())

        args += tmp;

    return args;

}

/*!

    \overload

    Starts the program \a program in a new process, if one is not already

    running. \a program is a single string of text containing both the

    program name and its arguments. The arguments are separated by one or

    more spaces. For example: