KProcess Class Reference

from PyKDE4.kdecore import *

Inherits: QProcess → QIODevice → QObject

Detailed Description

\class KProcess kprocess.h <KProcess>

Child process invocation, monitoring and control.

This class extends QProcess by some useful functionality, overrides some defaults with saner values and wraps parts of the API into a more accessible one. This is the preferred way of spawning child processes in KDE; don't use QProcess directly.

Author:: Oswald Buddenhagen <ossi@kde.org>

Enumerations
OutputChannelMode	{ SeparateChannels, MergedChannels, ForwardedChannels, OnlyStdoutChannel, OnlyStderrChannel }
Methods
	__init__ (self, QObject parent=0)
	__init__ (self, KProcessPrivate d, QObject parent)
	clearEnvironment (self)
	clearProgram (self)
int	execute (self, int msecs=-1)
KProcess	operator << (self, QString arg)
KProcess	operator << (self, QStringList args)
KProcess.OutputChannelMode	outputChannelMode (self)
int	pid (self)
QStringList	program (self)
	setEnv (self, QString name, QString value, bool overwrite=1)
	setNextOpenMode (self, QIODevice.OpenMode mode)
	setOutputChannelMode (self, KProcess.OutputChannelMode mode)
	setProgram (self, QString exe, QStringList args=QStringList())
	setProgram (self, QStringList argv)
	setShellCommand (self, QString cmd)
	start (self)
int	startDetached (self)
	unsetEnv (self, QString name)
Static Methods
int	execute (QString exe, QStringList args=QStringList(), int msecs=-1)
int	execute (QStringList argv, int msecs=-1)
int	startDetached (QString exe, QStringList args=QStringList())
int	startDetached (QStringList argv)

Method Documentation

__init__	(	self,
		QObject	parent=0
	)

Constructor

__init__	(	self,
		KProcessPrivate	d,
		QObject	parent
	)

Internal:

clearEnvironment ( self )

Empties the process' environment.

Note that LD_LIBRARY_PATH/DYLD_LIBRARY_PATH is automatically added on *NIX.

This function must be called before starting the process.

clearProgram ( self )

Clear the program and command line argument list.

int execute	(	self,
		int	msecs=-1
	)

Start the process, wait for it to finish, and return the exit code.

This method is roughly equivalent to the sequence:

start();
waitForFinished(msecs);
return exitCode();

Unlike the other execute() variants this method is not static, so the process can be parametrized properly and talked to.

Parameters:

msecs

time to wait for process to exit before killing it

Returns:: -2 if the process could not be started, -1 if it crashed, otherwise its exit code

int execute	(	QString	exe,
		QStringList	args=QStringList(),
		int	msecs=-1
	)

Parameters:

	exe	the program to execute
	args	the command line arguments for the program, one per list element
	msecs	time to wait for process to exit before killing it

Returns:: -2 if the process could not be started, -1 if it crashed, otherwise its exit code

int execute	(	QStringList	argv,
		int	msecs=-1
	)

Parameters:

	argv	the program to execute and the command line arguments for the program, one per list element
	msecs	time to wait for process to exit before killing it

Returns:: -2 if the process could not be started, -1 if it crashed, otherwise its exit code

KProcess operator <<	(	self,
		QString	arg
	)

Append an element to the command line argument list for this process.

If no executable is set yet, it will be set instead.

For example, doing an "ls -l /usr/local/bin" can be achieved by:

  KProcess p;
  p << "ls" << "-l" << "/usr/local/bin";
  ...

This function must be called before starting the process, obviously.

Parameters:

arg

the argument to add

Returns:: a reference to this KProcess

KProcess operator <<	(	self,
		QStringList	args
	)

Parameters:

args

the arguments to add

Returns:: a reference to this KProcess

KProcess.OutputChannelMode outputChannelMode ( self )

Query how the output channels of the child process are handled.

Returns:: the output channel handling mode

int pid ( self )

Obtain the process' ID as known to the system.

Unlike with QProcess.pid(), this is a real PID also on Windows.

This function can be called only while the process is running. It cannot be applied to detached processes.

Returns:: the process ID

QStringList program ( self )

Obtain the currently set program and arguments.

Returns:: a list, the first element being the program, the remaining ones being command line arguments to the program.

setEnv	(	self,
		QString	name,
		QString	value,
		bool	overwrite=1
	)

Adds the variable name to the process' environment.

This function must be called before starting the process.

Parameters:

	name	the name of the environment variable
	value	the new value for the environment variable
	overwrite	if false and the environment variable is already set, the old value will be preserved

setNextOpenMode	(	self,
		QIODevice.OpenMode	mode
	)

Set the QIODevice open mode the process will be opened in.

This function must be called before starting the process, obviously.

Parameters:

mode

the open mode. Note that this mode is automatically "reduced" according to the channel modes and redirections. The default is QIODevice.ReadWrite.

setOutputChannelMode	(	self,
		KProcess.OutputChannelMode	mode
	)

Set how to handle the output channels of the child process.

The default is ForwardedChannels, which is unlike in QProcess. Do not request more than you actually handle, as this output is simply lost otherwise.

This function must be called before starting the process.

Parameters:

mode

the output channel handling mode

setProgram	(	self,
		QString	exe,
		QStringList	args=QStringList()
	)

Set the program and the command line arguments.

This function must be called before starting the process, obviously.

Parameters:

	exe	the program to execute
	args	the command line arguments for the program, one per list element

setProgram	(	self,
		QStringList	argv
	)

Parameters:

argv

the program to execute and the command line arguments for the program, one per list element

setShellCommand	(	self,
		QString	cmd
	)

Set a command to execute through a shell (a POSIX sh on *NIX and cmd.exe on Windows).

Using this for anything but user-supplied commands is usually a bad idea, as the command's syntax depends on the platform. Redirections including pipes, etc. are better handled by the respective functions provided by QProcess.

If KProcess determines that the command does not really need a shell, it will trasparently execute it without one for performance reasons.

This function must be called before starting the process, obviously.

Parameters:

cmd

the command to execute through a shell. The caller must make sure that all filenames etc. are properly quoted when passed as argument. Failure to do so often results in serious security holes. See KShell.quoteArg().

start ( self )

Start the process.

See also:: QProcess.start(const QString &, const QStringList &, OpenMode)

int startDetached ( self )

Start the process and detach from it. See QProcess.startDetached() for details.

Unlike the other startDetached() variants this method is not static, so the process can be parametrized properly.

Note:: Currently, only the setProgram()/setShellCommand() and setWorkingDirectory() parametrizations are supported.

The KProcess object may be re-used immediately after calling this function.

Returns:: the PID of the started process or 0 on error

int startDetached	(	QString	exe,
		QStringList	args=QStringList()
	)

Parameters:

	exe	the program to start
	args	the command line arguments for the program, one per list element

Returns:: the PID of the started process or 0 on error

int startDetached	(	QStringList	argv
	)

Parameters:

argv

the program to start and the command line arguments for the program, one per list element

Returns:: the PID of the started process or 0 on error

unsetEnv	(	self,
		QString	name
	)

Removes the variable name from the process' environment.

This function must be called before starting the process.

Parameters:

name

the name of the environment variable

Enumeration Documentation

OutputChannelMode

Modes in which the output channels can be opened.

Enumerator:

SeparateChannels = QProcess::SeparateChannels
MergedChannels = QProcess::MergedChannels
ForwardedChannels = QProcess::ForwardedChannels
OnlyStdoutChannel
OnlyStderrChannel

KProcess Class Reference

Detailed Description

Enumerations

Methods

Static Methods

Method Documentation

Enumeration Documentation

Modules