QProcess ¶

函数 ¶

虚函数 ¶

槽 ¶

信号 ¶

静态函数 ¶

运行进程 ¶

要启动进程，把希望运行的程序名称和命令行自变量作为自变量传递给 start() . Arguments are supplied as individual strings in a QStringList .

另外，可以设置要运行的程序采用 setProgram() and setArguments() , and then call start() or open() .

For example, the following code snippet runs the analog clock example in the Fusion style on X11 platforms by passing strings containing “-style” and “fusion” as two items in the list of arguments:

QObject *parent;
...
QString program = "./path/to/Qt/examples/widgets/analogclock";
QStringList arguments;
arguments << "-style" << "fusion";
QProcess *myProcess = new QProcess(parent);
myProcess->start(program, arguments);
												

QProcess then enters the Starting state, and when the program has started, QProcess enters the 运行 状态并发射 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() ，和 getChar() . Because it inherits QIODevice , QProcess can also be used as an input source for QXmlReader ，或对于生成要上传的数据使用 QNetworkAccessManager .

When the process exits, QProcess reenters the NotRunning 状态 (初始状态)，并发射 finished() .

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 将发射 errorOccurred() signal. You can also call error() to find the type of error that occurred last, and state() to find the current process state.

注意

QProcess is not supported on VxWorks, iOS, tvOS, watchOS, or the Universal Windows Platform.

凭借通道通信 ¶

进程有 2 个预定义输出通道：标准输出通道 ( stdout ) 提供常规控制台输出，和标准错误通道 ( stderr ) 通常提供由进程打印的错误。这些通道表示 2 个单独数据流。可以在它们之间切换通过调用 setReadChannel() . QProcess 发射 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() ，或 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 read channels, whereas the process’s input channels correspond to QProcess ‘s 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 在开始激活此特征的进程之前。还有将正运行进程输出转发到调用主进程的选项，通过传递 ForwardedChannels 作为自变量。只转发某个输出通道是可能的 - 通常会使用 ForwardedErrorChannel ，但 ForwardedOutputChannel 也存在。注意，在 GUI 应用程序中使用通道转发通常是个坏主意 - 应该以图形呈现错误取而代之。

某些进程需要特殊环境设置才能运转。可以为进程设置环境变量通过调用 setProcessEnvironment() . To set a working directory, call setWorkingDirectory() . By default, processes are run in the current working directory of the calling process.

The positioning and the screen Z-order of windows belonging to GUI applications started with QProcess are controlled by the underlying windowing system. For Qt 5 applications, the positioning can be specified using the -qwindowgeometry 命令行选项；X11 应用程序一般接受 -geometry 命令行选项。

注意

On QNX, setting the working directory may cause all application threads, with the exception of the QProcess caller thread, to temporarily freeze during the spawning process, owing to a limitation in the operating system.

同步进程 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:

• waitForStarted() blocks until the process has started.

• waitForReadyRead() blocks until new data is available for reading on the current read channel.

• waitForBytesWritten() blocks until one payload of data has been written to the process.

• waitForFinished() blocks until the process has finished.

从主线程调用这些函数 (线程调用 exec() ) may cause your user interface to freeze.

以下范例运行 gzip to compress the string “Qt rocks!”, without an event loop:

QProcess gzip;
gzip.start("gzip", QStringList() << "-c");
if (!gzip.waitForStarted())
    return false;
gzip.write("Qt rocks!");
gzip.closeWriteChannel();
if (!gzip.waitForFinished())
    return false;
QByteArray result = gzip.readAll();
												

Windows 用户注意事项 ¶

某些 Windows 命令 (例如， 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 ( cmd.exe 在某些 Windows 系统)，和要求解释器执行期望命令。

另请参阅

QBuffer QFile QTcpSocket

class QProcess ( [ parent=None ] ) ¶

param parent

QObject

构造 QProcess 对象采用给定 parent .

PySide2.QtCore.QProcess. ProcessError ¶

此枚举描述错误的不同类型，报告通过 QProcess .

常量	描述
QProcess.FailedToStart	The process failed to start. Either the invoked program is missing, or you may have insufficient permissions to invoke the program.
QProcess.Crashed	进程有时崩溃在成功启动后。
QProcess.Timedout	The last waitFor…() function timed out. The state of QProcess is unchanged, and you can try calling waitFor…() again.
QProcess.WriteError	发生错误当试图写入进程时。例如，进程可能未运行，或它可能已关闭其输入通道。
QProcess.ReadError	发生错误当试图从进程读取时。例如，进程可能未运行。
QProcess.UnknownError	发生未知错误。这是默认返回值为 error() .

另请参阅

error()

PySide2.QtCore.QProcess. ProcessState ¶

此枚举描述不同状态为 QProcess .

常量	描述
QProcess.NotRunning	进程未运行。
QProcess.Starting	进程正在启动，但尚未援引程序。
QProcess.Running	进程正在运行且读写就绪。

另请参阅

state()

PySide2.QtCore.QProcess. ProcessChannel ¶

此枚举描述正运行进程所使用的进程通道。传递这些值之一给 setReadChannel() to set the current read channel of QProcess .

常量	描述
QProcess.StandardOutput	正运行进程的 stdout (标准输出)。
QProcess.StandardError	正运行进程的 stderr (标准错误)。

另请参阅

setReadChannel()

PySide2.QtCore.QProcess. ProcessChannelMode ¶

此枚举描述进程的输出通道模式为 QProcess 。将这些值之一传递给 setProcessChannelMode() to set the current read channel mode.

常量	描述
QProcess.SeparateChannels	QProcess 管理正运行进程的输出，将标准输出和标准错误数据保持在单独内部缓冲中。可以选择 QProcess ‘s current read channel by calling setReadChannel() . This is the default channel mode of QProcess .
QProcess.MergedChannels	QProcess 将正运行进程的输出合并到标准输出通道 ( stdout )。标准错误通道 ( stderr ) will not receive any data. The standard output and standard error data of the running process are interleaved.
QProcess.ForwardedChannels	QProcess 将正运行进程的输出转发到主进程。由子级进程写入其标准输出和标准错误的任何内容，都将写入主进程的标准输出和标准错误。
QProcess.ForwardedErrorChannel	QProcess 管理正运行进程的标准输出，但将其标准错误转发到主进程。这反映命令行工具作为过滤器的典型用法，其中标准输出被重定向到另一进程或文件，而标准错误被打印到控制台为诊断目的。(该值在 Qt 5.2 引入。)
QProcess.ForwardedOutputChannel	Complementary to . (This value was introduced in Qt 5.2.)

注意

Windows 有意抑制从仅 GUI 应用程序输出到继承控制台。 这 not apply to output redirected to files or pipes. To forward the output of GUI-only applications on the console nonetheless, you must use and do the forwarding yourself by reading the output and writing it to the appropriate output channels.

另请参阅

setProcessChannelMode()

PySide2.QtCore.QProcess. InputChannelMode ¶

此枚举描述进程输入通道模式为 QProcess 。将这些值之一传递给 setInputChannelMode() to set the current write channel mode.

常量	描述
QProcess.ManagedInputChannel	QProcess 管理正运行进程的输入。这是默认输入通道模式为 QProcess .
QProcess.ForwardedInputChannel	QProcess 把主进程的输入转发给正运行进程。子级进程从与主进程相同的源读取其标准输入。注意：主进程不得试着读取其标准输入当子级进程正在运行时。

另请参阅

setInputChannelMode()

PySide2.QtCore.QProcess. ExitStatus ¶

此枚举描述不同退出状态为 QProcess .

常量	描述
QProcess.NormalExit	进程正常退出。
QProcess.CrashExit	进程崩溃。

另请参阅

exitStatus()

PySide2.QtCore.QProcess. arguments ( ) ¶

返回类型

字符串列表

返回上次启动进程采用的命令行自变量。

另请参阅

setArguments() start()

PySide2.QtCore.QProcess. closeReadChannel ( channel ) ¶

参数

channel – ProcessChannel

关闭读取通道 channel 。在调用此函数后， QProcess 将不再接收通道数据。任何已收到的数据仍可用于读取。

调用此函数以节省内存，若对进程的输出不感兴趣。

另请参阅

closeWriteChannel() setReadChannel()

PySide2.QtCore.QProcess. closeWriteChannel ( ) ¶

调度写入通道对于 QProcess 要被关闭。一旦所有数据被写入进程，通道就将关闭。在调用此函数后，任何写入进程的试图都将失败。

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:

more = QProcess()
more.start("more")
more.write("Text to display")
more.closeWriteChannel()
#QProcess will emit readyRead() once "more" starts printing
												

写入通道被隐式打开当 start() 被调用。

另请参阅

closeReadChannel()

PySide2.QtCore.QProcess. environment ( ) ¶

返回类型

字符串列表

返回环境 QProcess will pass to its child 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.

另请参阅

processEnvironment() setEnvironment() systemEnvironment()

PySide2.QtCore.QProcess. error ( ) ¶

返回类型

ProcessError

返回最后发生的错误类型。

另请参阅

state()

PySide2.QtCore.QProcess. error ( error ) ¶

参数

error – ProcessError

注意

此函数被弃用。

PySide2.QtCore.QProcess. errorOccurred ( error ) ¶

参数

error – ProcessError

static PySide2.QtCore.QProcess. execute ( command ) ¶

参数

command – unicode

返回类型

int

注意

此函数被弃用。

这是重载函数。

启动程序 command in a new process, waits for it to finish, and then returns the exit code.

自变量处理分别等同 start() overload.

之后 command string has been split and unquoted, this function behaves like the overload which takes the arguments as a string list.

另请参阅

start() splitCommand()

static PySide2.QtCore.QProcess. execute ( program , arguments ) ¶

参数

• program – unicode

• arguments – 字符串列表

返回类型

int

启动程序 program 采用自变量 arguments 在新进程中，等待它完成，然后返回进程的退出代码。新进程写入控制台的任何数据会被转发给调用进程。

环境和工作目录继承自调用进程。

自变量处理分别等同 start() overload.

If the process cannot be started, -2 is returned. If the process crashes, -1 is returned. Otherwise, the process’ exit code is returned.

另请参阅

start()

PySide2.QtCore.QProcess. exitCode ( ) ¶

返回类型

int

返回最后完成进程的退出代码。

此值无效除非 exitStatus() 返回 NormalExit .

PySide2.QtCore.QProcess. exitStatus ( ) ¶

返回类型

ExitStatus

返回最后完成的进程退出状态。

在 Windows，若进程被另一应用程序的 TerminateProcess() 所终止，此函数仍会返回 NormalExit 除非退出代码小于 0。

PySide2.QtCore.QProcess. finished ( exitCode , exitStatus ) ¶

参数

• exitCode – int

• exitStatus – ExitStatus

PySide2.QtCore.QProcess. finished ( exitCode ) ¶

参数

exitCode – int

注意

此函数被弃用。

PySide2.QtCore.QProcess. inputChannelMode ( ) ¶

返回类型

InputChannelMode

返回通道模式对于 QProcess 标准输入通道。

另请参阅

setInputChannelMode() InputChannelMode

PySide2.QtCore.QProcess. kill ( ) ¶

杀除当前进程，导致它立即退出。

On Windows, uses TerminateProcess, and on Unix and macOS, the SIGKILL signal is sent to the process.

另请参阅

terminate()

static PySide2.QtCore.QProcess. nullDevice ( ) ¶

返回类型

unicode

操作系统的 null 设备。

返回的文件路径使用本机目录分隔符。

另请参阅

setStandardInputFile() setStandardOutputFile() setStandardErrorFile()

PySide2.QtCore.QProcess. processChannelMode ( ) ¶

返回类型

ProcessChannelMode

返回通道模式对于 QProcess 标准输出和标准错误通道。

另请参阅

setProcessChannelMode() ProcessChannelMode setReadChannel()

PySide2.QtCore.QProcess. processEnvironment ( ) ¶

返回类型

QProcessEnvironment

返回环境 QProcess will pass to its child process, or an empty object if no environment has been set using setEnvironment() or setProcessEnvironment() . If no environment has been set, the environment of the calling process will be used.

另请参阅

setProcessEnvironment() setEnvironment() isEmpty()

PySide2.QtCore.QProcess. processId ( ) ¶

返回类型

qint64

返回正在运行进程的本机进程标识符，若可用。若目前没有进程正在运行， 0 被返回。

PySide2.QtCore.QProcess. program ( ) ¶

返回类型

unicode

返回进程最后一次启动时采用的程序。

另请参阅

setProgram() start()

PySide2.QtCore.QProcess. readAllStandardError ( ) ¶

返回类型

QByteArray

不管当前读取通道，此函数从进程标准错误返回所有可用数据按 QByteArray .

另请参阅

readyReadStandardError() readAllStandardOutput() readChannel() setReadChannel()

PySide2.QtCore.QProcess. readAllStandardOutput ( ) ¶

返回类型

QByteArray

不管当前读取通道，此函数从进程标准输出返回所有可用数据按 QByteArray .

另请参阅

readyReadStandardOutput() readAllStandardError() readChannel() setReadChannel()

PySide2.QtCore.QProcess. readChannel ( ) ¶

返回类型

ProcessChannel

返回当前读取通道为 QProcess .

另请参阅

setReadChannel()

PySide2.QtCore.QProcess. setArguments ( arguments ) ¶

参数

arguments – 字符串列表

设置 arguments 以传递给被调用程序当启动进程时。必须调用此函数先于 start() .

另请参阅

start() setProgram() arguments()

PySide2.QtCore.QProcess. setEnvironment ( environment ) ¶

参数

environment – 字符串列表

Sets the environment that QProcess will pass to the child process. The parameter environment is a list of key=value pairs.

例如，以下代码添加环境变量 TMPDIR :

QProcess process;
QStringList env = QProcess::systemEnvironment();
env << "TMPDIR=C:\\MyApp\\temp"; // Add an environment variable
process.setEnvironment(env);
process.start("myapp");
												

注意

This function is less efficient than the setProcessEnvironment() 函数。

另请参阅

environment() setProcessEnvironment() systemEnvironment()

PySide2.QtCore.QProcess. setInputChannelMode ( mode ) ¶

参数

mode – InputChannelMode

设置通道模式为 QProcess 标准输入通道到 mode 指定。会使用此模式当下次 start() 被调用。

另请参阅

inputChannelMode() InputChannelMode

PySide2.QtCore.QProcess. setProcessChannelMode ( mode ) ¶

参数

mode – ProcessChannelMode

设置通道模式为 QProcess 标准输出和标准错误通道到 mode 指定。会使用此模式当下次 start() is called. For example:

builder = QProcess()
builder.setProcessChannelMode(QProcess.MergedChannels)
builder.start("make", ["-j2"])
import sys
if not builder.waitForFinished():
    sys.stderr.write("Make failed:" + builder.errorString())
else
    sys.stderr.write("Make output:" + builder.readAll())
												

另请参阅

processChannelMode() ProcessChannelMode setReadChannel()

PySide2.QtCore.QProcess. setProcessEnvironment ( environment ) ¶

参数

environment – QProcessEnvironment

设置 environment that QProcess 将传递给子级进程。

例如，以下代码添加环境变量 TMPDIR :

QProcess process;
QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
env.insert("TMPDIR", "C:\\MyApp\\temp"); // Add an environment variable
process.setProcessEnvironment(env);
process.start("myapp");
												

注意：在 Windows，环境变量名称是不区分大小写的。

另请参阅

processEnvironment() systemEnvironment() setEnvironment()

PySide2.QtCore.QProcess. setProcessState ( state ) ¶

参数

state – ProcessState

设置当前状态为 QProcess 到 state 指定。

另请参阅

state()

PySide2.QtCore.QProcess. setProgram ( program ) ¶

参数

program – unicode

设置 program to use when starting the process. This function must be called before start() .

另请参阅

start() setArguments() program()

PySide2.QtCore.QProcess. setReadChannel ( channel ) ¶

参数

channel – ProcessChannel

设置当前读取通道为 QProcess 到给定 channel 。当前输入通道用于函数 read() , readAll() , readLine() ，和 getChar() . It also determines which channel triggers QProcess 以发射 readyRead() .

另请参阅

readChannel()

PySide2.QtCore.QProcess. setStandardErrorFile ( fileName [ , mode=QIODevice.Truncate ] ) ¶

参数

• fileName – unicode

• mode – OpenMode

Redirects the process’ standard error to the file 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 mode is Append, otherwise, it will be truncated.

见 setStandardOutputFile() for more information on how the file is opened.

Note: if setProcessChannelMode() was called with an argument of MergedChannels ，此函数不起作用。

另请参阅

setStandardInputFile() setStandardOutputFile() setStandardOutputProcess()

PySide2.QtCore.QProcess. setStandardInputFile ( fileName ) ¶

参数

fileName – unicode

Redirects the process’ standard input to the file indicated by fileName . When an input redirection is in place, the QProcess object will be in read-only mode (calling write() will result in error).

To make the process read EOF right away, pass nullDevice() here. This is cleaner than using closeWriteChannel() before writing any data, because it can be set up prior to starting the process.

If the file fileName does not exist at the moment start() is called or is not readable, starting the process will fail.

Calling after the process has started has no effect.

另请参阅

setStandardOutputFile() setStandardErrorFile() setStandardOutputProcess()

PySide2.QtCore.QProcess. setStandardOutputFile ( fileName [ , mode=QIODevice.Truncate ] ) ¶

参数

• fileName – unicode

• mode – OpenMode

Redirects the process’ standard output to the file 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() .

To discard all standard output from the process, pass nullDevice() here. This is more efficient than simply never reading the standard output, as no QProcess buffers are filled.

If the file 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 mode is Truncate , the file will be truncated. Otherwise (if mode is 追加 ), the file will be appended to.

Calling after the process has started has no effect.

另请参阅

setStandardInputFile() setStandardErrorFile() setStandardOutputProcess()

PySide2.QtCore.QProcess. setStandardOutputProcess ( destination ) ¶

参数

destination – QProcess

将此进程的标准输出流管道到 destination process’ standard input.

以下 Shell 命令：

command1 | command2
												

可以完成采用 QProcess 通过以下代码：

process1 = QProcess()
process2 = QProcess()
process1.setStandardOutputProcess(process2)
process1.start("command1")
process2.start("command2")
												

PySide2.QtCore.QProcess. setWorkingDirectory ( dir ) ¶

参数

dir – unicode

把工作目录设为 dir . QProcess 将在此目录下启动进程。默认行为是在调用进程的工作目录下启动进程。

注意

在 QNX，这可能导致所有应用程序线程被临时冻结。

另请参阅

workingDirectory() start()

PySide2.QtCore.QProcess. setupChildProcess ( ) ¶

This function is called in the child process context just before the program is executed on Unix or macOS (i.e., after fork() , but before execve() ). Reimplement this function to do last minute initialization of the child process. Example:

class SandboxProcess(QProcess):
    def setupChildProcess(self)
        # Drop all privileges in the child process, and enter
        # a chroot jail.
        os.setgroups(0, 0)
        os.chroot("/etc/safe")
        os.chdir("/")
        os.setgid(safeGid)
        os.setuid(safeUid)
        os.umask(0)
												

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().

警告

此函数被调用由 QProcess on Unix and macOS only. On Windows and QNX, it is not called.

PySide2.QtCore.QProcess. start ( [ mode=QIODevice.ReadWrite ] ) ¶

参数

mode – OpenMode

这是重载函数。

启动程序设置通过 setProgram() with arguments set by setArguments() 。 OpenMode is set to mode .

另请参阅

open() setProgram() setArguments()

PySide2.QtCore.QProcess. start ( command [ , mode=QIODevice.ReadWrite ] ) ¶

参数

• command – unicode

• mode – OpenMode

注意

此函数被弃用。

这是重载函数。

启动命令 command in a new process. The OpenMode is set to mode .

command 是包含程序名称及其自变量的单文本字符串。自变量由一个或多个空格分隔。例如：

process = QProcess()
process.start("del /s *.txt")
# same as process.start("del", ["/s", "*.txt"])
...
												

必须引用包含空格的自变量才能被正确提供给新进程。例如：

process = QProcess()
process.start("dir \"My Documents\"")
												

文字引号在 command 字符串由 3 引号表示。例如：

process = QProcess()
process.start("dir \"\"\"My Documents\"\"\"")
												

之后 command string has been split and unquoted, this function behaves like the overload which takes the arguments as a string list.

You can disable this overload by defining QT_NO_PROCESS_COMBINED_ARGUMENT_START when you compile your applications. This can be useful if you want to ensure that you are not splitting arguments unintentionally, for example. In virtually all cases, using the other overload is the preferred method.

在将命令行自变量传递给子进程的本机系统 API 使用单字符串的 Windows 操作系统，可以设想无法传递命令行凭借 QProcess ‘s portable list-based API. In these rare cases you need to use setProgram() and setNativeArguments() instead of this function.

另请参阅

splitCommand()

PySide2.QtCore.QProcess. start ( program , arguments [ , mode=QIODevice.ReadWrite ] ) ¶

参数

• program – unicode

• arguments – 字符串列表

• mode – OpenMode

启动给定 program 在新进程，传递的命令行自变量在 arguments .

QProcess 对象将立即进入 Starting 状态。若进程成功启动， QProcess 将发射 started() ；否则， errorOccurred() 会被发射。

注意

进程是异步启动的，这意味着 started() and errorOccurred() signals may be delayed. Call waitForStarted() to make sure the process has started (or has failed to start) and those signals have been emitted.

注意

不履行进一步的自变量分割。

Windows: 自变量加引号并被拼接到兼容命令行采用 CommandLineToArgvW() Windows 函数。对于有不同命令行要求加引号的程序，需要使用 setNativeArguments() . One notable program that does not follow the CommandLineToArgvW() 规则是 cmd.exe，因此是所有批处理脚本。

OpenMode is set to mode .

若 QProcess 对象已在运行进程，可能在控制台打印警告，且现有进程将不受影响地继续运行。

另请参阅

processId() started() waitForStarted() setNativeArguments()

static PySide2.QtCore.QProcess. startDetached ( command ) ¶

参数

command – unicode

返回类型

bool

注意

此函数被弃用。

static PySide2.QtCore.QProcess. startDetached ( program , arguments ) ¶

参数

• program – unicode

• arguments – 字符串列表

返回类型

bool

static PySide2.QtCore.QProcess. startDetached ( program , arguments , workingDirectory ) ¶

参数

• program – unicode

• arguments – 字符串列表

• workingDirectory – unicode

返回类型

(retval, pid)

此函数重载 startDetached() .

启动程序 program 采用自变量 arguments 在新进程中，并与之分离。返回 true 当成功时；否则返回 false 。若调用进程退出，分离进程将不受影响地继续运行。

自变量处理分别等同 start() overload.

进程将被启动在目录 workingDirectory 。若 workingDirectory 为空，工作目录继承自调用进程。

If the function is successful then *``pid`` is set to the process identifier of the started process.

另请参阅

start()

PySide2.QtCore.QProcess. startDetached ( [ pid=None ] ) ¶

参数

pid – qint64

返回类型

bool

启动程序设置通过 setProgram() with arguments set by setArguments() 在新进程中，并与之分离。返回 true 当成功时；否则返回 false 。若调用进程退出，分离进程将不受影响地继续运行。

Unix: 启动进程将在它自己的会话中运行，且行动像守护程序。

进程将在指定目录下启动设置通过 setWorkingDirectory() 。若 workingDirectory() 为空，工作目录继承自调用进程。

注意

在 QNX，这可能导致所有应用程序线程被临时冻结。

If the function is successful then *``pid`` is set to the process identifier of the started process. Note that the child process may exit and the PID may become invalid without notice. Furthermore, after the child process exits, the same PID may be recycled and used by a completely different process. User code should be careful when using this variable, especially if one intends to forcibly terminate the process by operating system means.

Only the following property setters are supported by :

• setArguments()

• setCreateProcessArgumentsModifier()

• setNativeArguments()

• setProcessEnvironment()

• setProgram()

• setStandardErrorFile()

• setStandardInputFile()

• setStandardOutputFile()

• setWorkingDirectory()

所有其它特性对于 QProcess 对象被忽略。

注意

被调用进程继承调用进程的控制台窗口。要抑制控制台输出，请将标准/错误输出重定向到 nullDevice() .

另请参阅

start() startDetached(const QString &program, const QStringList &arguments, const QString &workingDirectory, qint64 *pid) startDetached(const QString &command)

PySide2.QtCore.QProcess. state ( ) ¶

返回类型

ProcessState

返回进程的当前状态。

另请参阅

stateChanged() error()

static PySide2.QtCore.QProcess. systemEnvironment ( ) ¶

返回类型

字符串列表

以 key=value 对列表形式返回调用进程的环境。范例：

environment = QProcess.systemEnvironment()
# environment = [PATH=/usr/bin:/usr/local/bin",
#                "USER=greg", "HOME=/home/greg"]
												

This function does not cache the system environment. Therefore, it’s possible to obtain an updated version of the environment if low-level C library functions like setenv or putenv 有被调用。

不管怎样，注意，重复调用此函数将重新创建环境变量列表 (非通俗操作)。

注意

对于新代码，推荐使用 systemEnvironment()

另请参阅

systemEnvironment() setProcessEnvironment()

PySide2.QtCore.QProcess. terminate ( ) ¶

试图终止进程。

进程可能不会因调用此函数而退出 (它有机会提示用户是否有未保存的文件，等等)。

On Windows, posts a WM_CLOSE message to all top-level windows of the process and then to the main thread of the process itself. On Unix and macOS the SIGTERM 信号被发送。

不运行事件循环的 Windows 控制台应用程序 (或其事件循环不处理 WM_CLOSE 消息)，只可被终止通过调用 kill() .

另请参阅

kill()

PySide2.QtCore.QProcess. waitForFinished ( [ msecs=30000 ] ) ¶

参数

msecs – int

返回类型

bool

阻塞直到进程已完成且 finished() signal has been emitted, or until msecs 毫秒已过去。

返回 true 若进程已完成；否则返回 false (若操作超时，若发生错误，或者若此 QProcess 已完成)。

可以在没有事件循环的情况下操作此函数。它很有用，当编写非 GUI 应用程序和在非 GUI 线程中履行 I/O 操作时。

警告

从主 GUI 线程调用此函数可能导致用户界面被冻结。

若 msecs 为 -1，此函数不会超时。

另请参阅

finished() waitForStarted() waitForReadyRead() waitForBytesWritten()

PySide2.QtCore.QProcess. waitForStarted ( [ msecs=30000 ] ) ¶

参数

msecs – int

返回类型

bool

阻塞直到进程启动且 started() signal has been emitted, or until msecs 毫秒已过去。

返回 true 若进程成功启动；否则返回 false (若操作超时或发生错误)。

可以在没有事件循环的情况下操作此函数。它很有用，当编写非 GUI 应用程序和在非 GUI 线程中履行 I/O 操作时。

警告

从主 GUI 线程调用此函数可能导致用户界面被冻结。

若 msecs 为 -1，此函数不会超时。

注意

在某些 UNIX 操作系统，此函数可能返回 true 但进程可能稍后报告 FailedToStart 错误。

另请参阅

started() waitForReadyRead() waitForBytesWritten() waitForFinished()

PySide2.QtCore.QProcess. workingDirectory ( ) ¶

返回类型

unicode

若 QProcess 已赋值工作目录，此函数返回工作目录 QProcess 将在程序开始之前进入。否则，返回空字符串 (即：没有赋值目录)，且 QProcess will use the application’s current working directory instead.

另请参阅

setWorkingDirectory()