qprocess.cpp

奇趣公司比较新的qt/emd版本

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//#define QPROCESS_DEBUG

#if defined QPROCESS_DEBUG
#include <qdebug.h>
#include <qstring.h>
#include <ctype.h>
#include <errno.h>

/*
    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;
}
#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

/*!
    \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:

    \quotefromfile snippets/qprocess/qprocess-simpleexecution.cpp
    \skipto parent
    \printline parent
    \dots
    \skipto program
    \printline program
    \skipto QStringList
    \printuntil start

    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.

    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.

    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.

    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:

    \quotefromfile snippets/process/process.cpp
    \skipto QProcess gzip;
    \printuntil result = gzip.readAll();

    \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()
{
    processState = QProcess::NotRunning;
#ifdef Q_OS_WIN
    if (pid) {
        CloseHandle(pid->hThread);
        CloseHandle(pid->hProcess);
        delete pid;
        pid = 0;
    }
    if (processFinishedNotifier) {
        processFinishedNotifier->setEnabled(false);
        delete processFinishedNotifier;
        processFinishedNotifier = 0;
    }

#endif
    pid = 0;
    sequenceNumber = 0;
    dying = false;

    if (stdoutChannel.notifier) {
        stdoutChannel.notifier->setEnabled(false);
        delete stdoutChannel.notifier;
        stdoutChannel.notifier = 0;
    }
    if (stderrChannel.notifier) {
        stderrChannel.notifier->setEnabled(false);
        delete stderrChannel.notifier;
        stderrChannel.notifier = 0;
    }
    if (stdinChannel.notifier) {
        stdinChannel.notifier->setEnabled(false);
        delete stdinChannel.notifier;
        stdinChannel.notifier = 0;
    }
    if (startupSocketNotifier) {
        startupSocketNotifier->setEnabled(false);
        delete startupSocketNotifier;
        startupSocketNotifier = 0;
    }