Process Class Reference

Used to start external programs and communicate with them. More...

Public Slots
void	abort ()
	Aborts a running process.
void	start ()
	Starts the process.

Signals
void	started ()
	This signal is emitted when the process is started.

Public Member Functions
Exitenumeration	exitStatus () const
	The last exit status of the process.
string	standardError ()
	The output from standard error (stderr).

Properties
string	command
	The command to be executed by the process.
Processenumeration	error
	The error that last occurred.
int	exitCode
	The last exit code of the process.
Q_PID	pid
	The unique process id.
ProcessChannelMode	processChannelMode
	The channel mode of the process standard output and standard error channels.
dict	processEnvironment
	The environment variables of the process.
ProcessChannel	readChannel
	The read channel of the process.
string	standardErrorFile
	The file to which standard error output is redirected.
string	standardInputFile
	The file to which standard input is redirected.
string	standardOutput
	The output from standard output (stdout).
string	standardOutputFile
	The file to which standard output is redirected.
Process	standardOutputProcess
	The Process to which standard output is redirected.
ProcessState	state
	The current state of the process.
string	workingDirectory
	The directory from which command is executed.

Detailed Description

Used to start external programs and communicate with them.

import QtQuick 1.0
import org.hildon.components 1.0
import org.hildon.utils 1.0

Window {
    id: window
    
    title: qsTr("Process Example")
    visible: true
    
    Process {
        id: process
        
        command: textField.text
    }
    
    Column {
        id: column
        
        anchors {
            left: parent.left
            right: parent.right
            top: parent.top
            margins: platformStyle.paddingMedium
        }
        spacing: platformStyle.paddingMedium
        
        Label {
            width: parent.width
            text: qsTr("Command")
        }
        
        TextField {
            id: textField
            
            width: parent.width
            focus: true
            onAccepted: process.start()
        }
        
        Button {
            id: button
            
            width: parent.width
            text: process.state == Process.Running ? qsTr("Stop") : qsTr("Start")
            enabled: (textField.text != "") || (process.state == Process.Running)
            onClicked: process.state == Process.Running ? process.abort() : process.start()
        }
        
        Label {
            width: parent.width
            text: qsTr("Result")
        }
        
        TextArea {
            id: textArea
            
            width: parent.width
            readOnly: true
            text: process.standardOutput
        }
    }
}

Examples:

process.qml.

Member Function Documentation

Process::Exitenumeration Process::exitStatus

(

)

const

The last exit status of the process.

Possible values are:

Value	Description
Process.NormalExit	The process exited normally.
Process.CrashExit	The process crashed.

See Also

exitCode

void Process::start ( )

slot

Starts the process.

The started() signal will be emitted if the process was started successfully.

See Also

started(), state

void Process::started ( )

signal

This signal is emitted when the process is started.

See Also

start(), state

Property Documentation

Process::Processenumeration Process::error

read

The error that last occurred.

Possible values are:

Value	Description
Process.FailedToStart	The process failed to start.
Process.Crashed	The process crashed some time after starting successfully.
Process.WriteError	An error occurred when attempting to write to the process.
Process.ReadError	An error occurred when attempting to read from the process.
Process.UnknownError	An unknown error occurred (default).

int Process::exitCode

read

The last exit code of the process.

See Also

exitStatus

Process::ProcessChannelMode Process::processChannelMode

readwrite

The channel mode of the process standard output and standard error channels.

Possible values are:

Value	Description
Process.SeparateChannels	Process manages the output of the running process, keeping standard output and standard error data in separate internal buffers (default).
Process.MergedChannels	Process merges the output of the running process into the standard output channel (stdout). The standard error channel (stderr) will not receive any data.
Process.ForwardedChannels	Process forwards the output of the running process onto the main process.

See Also

readChannel

Process::ProcessChannel Process::readChannel

readwrite

The read channel of the process.

Possible values are:

Value	Description
Process.StandardOutput	The standard output (stdout) of the running process (default).
Process.StandardError	The standard error (stderr) of the running process.

string Process::standardErrorFile

readwrite

The file to which standard error output is redirected.

See Also

standardError

string Process::standardOutputFile

readwrite

The file to which standard output is redirected.

See Also

standardOutput

Process * Process::standardOutputProcess

readwrite

The Process to which standard output is redirected.

Setting this property to a valid Process is the equivalent of

$ process1 | process2

Set the property to null to reset.

See Also

standardOutput, standardOutputFile

Process::ProcessState Process::state

read

The current state of the process.

Possible values are:

Value	Description
Process.NotRunning	The process is not running (default).
Process.Starting	The process is starting, but the program has not yet been invoked.
Process.Running	The process is running and is ready for reading and writing.