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tqt3/src/kernel/qprocess.cpp

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/****************************************************************************
**
** Implementation of TQProcess class
**
** Created : 20000905
**
** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved.
**
** This file is part of the kernel module of the TQt GUI Toolkit.
**
** This file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free
** Software Foundation and appearing in the files LICENSE.GPL2
** and LICENSE.GPL3 included in the packaging of this file.
** Alternatively you may (at your option) use any later version
** of the GNU General Public License if such license has been
** publicly approved by Trolltech ASA (or its successors, if any)
** and the KDE Free TQt Foundation.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at sales@trolltech.com.
**
** This file may be used under the terms of the Q Public License as
** defined by Trolltech ASA and appearing in the file LICENSE.TQPL
** included in the packaging of this file. Licensees holding valid TQt
** Commercial licenses may use this file in accordance with the TQt
** Commercial License Agreement provided with the Software.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
** herein.
**
**********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include "ntqprocess.h"
#ifndef TQT_NO_PROCESS
#include "ntqapplication.h"
#include "private/qinternal_p.h"
//#define QT_QPROCESS_DEBUG
/*!
\class TQProcess ntqprocess.h
\brief The TQProcess class is used to start external programs and
to communicate with them.
\ingroup io
\ingroup misc
\mainclass
You can write to the started program's standard input, and can
read the program's standard output and standard error. You can
pass command line arguments to the program either in the
constructor or with setArguments() or addArgument(). The program's
working directory can be set with setWorkingDirectory(). If you
need to set up environment variables pass them to the start() or
launch() functions (see below). The processExited() signal is
emitted if the program exits. The program's exit status is
available from exitStatus(), although you could simply call
normalExit() to see if the program terminated normally.
There are two different ways to start a process. If you just want
to run a program, optionally passing data to its standard input at
the beginning, use one of the launch() functions. If you want full
control of the program's standard input (especially if you don't
know all the data you want to send to standard input at the
beginning), use the start() function.
If you use start() you can write to the program's standard input
using writeToStdin() and you can close the standard input with
closeStdin(). The wroteToStdin() signal is emitted if the data
sent to standard input has been written. You can read from the
program's standard output using readStdout() or readLineStdout().
These functions return an empty TQByteArray if there is no data to
read. The readyReadStdout() signal is emitted when there is data
available to be read from standard output. Standard error has a
set of functions that correspond to the standard output functions,
i.e. readStderr(), readLineStderr() and readyReadStderr().
If you use one of the launch() functions the data you pass will be
sent to the program's standard input which will be closed once all
the data has been written. You should \e not use writeToStdin() or
closeStdin() if you use launch(). If you need to send data to the
program's standard input after it has started running use start()
instead of launch().
Both start() and launch() can accept a string list of strings each
of which has the format, key=value, where the keys are the names
of environment variables.
You can test to see if a program is running with isRunning(). The
program's process identifier is available from
processIdentifier(). If you want to terminate a running program
use tryTerminate(), but note that the program may ignore this. If
you \e really want to terminate the program, without it having any
chance to clean up, you can use kill().
As an example, suppose we want to start the \c uic command (a TQt
command line tool used with \e{TQt Designer}) and perform some
operations on the output (the \c uic outputs the code it generates
to standard output by default). Suppose further that we want to
run the program on the file "small_dialog.ui" with the command
line options "-tr i18n". On the command line we would write:
\code
uic -tr i18n small_dialog.ui
\endcode
\quotefile process/process.cpp
A code snippet for this with the TQProcess class might look like
this:
\skipto UicManager::UicManager()
\printline UicManager::UicManager()
\printline {
\skipto proc = new TQProcess( this );
\printline proc = new TQProcess( this );
\skipto proc->addArgument( "uic" );
\printuntil this, TQ_SLOT(readFromStdout()) );
\skipto if ( !proc->start() ) {
\printuntil // error handling
\skipto }
\printline }
\printline }
\skipto void UicManager::readFromStdout()
\printuntil // Bear in mind that the data might be output in chunks.
\skipto }
\printline }
Although you may need quotes for a file named on the command line
(e.g. if it contains spaces) you shouldn't use extra quotes for
arguments passed to addArgument() or setArguments().
The readyReadStdout() signal is emitted when there is new data on
standard output. This happens asynchronously: you don't know if
more data will arrive later.
In the above example you could connect the processExited() signal
to the slot UicManager::readFromStdout() instead. If you do so,
you will be certain that all the data is available when the slot
is called. On the other hand, you must wait until the process has
finished before doing any processing.
Note that if you are expecting a lot of output from the process,
you may hit platform-dependent limits to the pipe buffer size. The
solution is to make sure you connect to the output, e.g. the
readyReadStdout() and readyReadStderr() signals and read the data
as soon as it becomes available.
Please note that TQProcess does not emulate a shell. This means that
TQProcess does not do any expansion of arguments: a '*' is passed as a '*'
to the program and is \e not replaced by all the files, a '$HOME' is also
passed literally and is \e not replaced by the environment variable HOME
and the special characters for IO redirection ('>', '|', etc.) are also
passed literally and do \e not have the special meaning as they have in a
shell.
Also note that TQProcess does not emulate a terminal. This means that
certain programs which need direct terminal control, do not work as
expected with TQProcess. Such programs include console email programs (like
pine and mutt) but also programs which require the user to enter a password
(like su and ssh).
\section1 Notes for Windows users
Some Windows commands, for example, \c dir, are not provided by
separate applications, but by the command interpreter.
If you attempt to use TQProcess 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.
Under Windows there are certain problems starting 16-bit applications
and capturing their output. Microsoft recommends using an intermediate
application to start 16-bit applications.
\sa TQSocket
*/
/*!
\enum TQProcess::Communication
This enum type defines the communication channels connected to the
process.
\value Stdin Data can be written to the process's standard input.
\value Stdout Data can be read from the process's standard
output.
\value Stderr Data can be read from the process's standard error.
\value DupStderr Both the process's standard error output \e and
its standard output are written to its standard output. (Like
Unix's dup2().) This means that nothing is sent to the standard
error output. This is especially useful if your application
requires that the output on standard output and on standard error
must be read in the same order that they are produced. This is a
flag, so to activate it you must pass \c{Stdout|Stderr|DupStderr},
or \c{Stdin|Stdout|Stderr|DupStderr} if you want to provide input,
to the setCommunication() call.
\sa setCommunication() communication()
*/
/*!
Constructs a TQProcess object. The \a parent and \a name parameters
are passed to the TQObject constructor.
\sa setArguments() addArgument() start()
*/
TQProcess::TQProcess( TQObject *parent, const char *name )
: TQObject( parent, name ), ioRedirection( FALSE ), notifyOnExit( FALSE ),
wroteToStdinConnected( FALSE ),
readStdoutCalled( FALSE ), readStderrCalled( FALSE ),
comms( Stdin|Stdout|Stderr )
{
init();
}
/*!
Constructs a TQProcess with \a arg0 as the command to be executed.
The \a parent and \a name parameters are passed to the TQObject
constructor.
The process is not started. You must call start() or launch() to
start the process.
\sa setArguments() addArgument() start()
*/
TQProcess::TQProcess( const TQString& arg0, TQObject *parent, const char *name )
: TQObject( parent, name ), ioRedirection( FALSE ), notifyOnExit( FALSE ),
wroteToStdinConnected( FALSE ),
readStdoutCalled( FALSE ), readStderrCalled( FALSE ),
comms( Stdin|Stdout|Stderr )
{
init();
addArgument( arg0 );
}
/*!
Constructs a TQProcess with \a args as the arguments of the
process. The first element in the list is the command to be
executed. The other elements in the list are the arguments to this
command. The \a parent and \a name parameters are passed to the
TQObject constructor.
The process is not started. You must call start() or launch() to
start the process.
\sa setArguments() addArgument() start()
*/
TQProcess::TQProcess( const TQStringList& args, TQObject *parent, const char *name )
: TQObject( parent, name ), ioRedirection( FALSE ), notifyOnExit( FALSE ),
wroteToStdinConnected( FALSE ),
readStdoutCalled( FALSE ), readStderrCalled( FALSE ),
comms( Stdin|Stdout|Stderr )
{
init();
setArguments( args );
}
/*!
Returns the list of arguments that are set for the process.
Arguments can be specified with the constructor or with the
functions setArguments() and addArgument().
Note that if you want to iterate over the list, you should iterate
over a copy, e.g.
\code
TQStringList list = myProcess.arguments();
TQStringList::Iterator it = list.begin();
while( it != list.end() ) {
myProcessing( *it );
++it;
}
\endcode
\sa setArguments() addArgument()
*/
TQStringList TQProcess::arguments() const
{
return _arguments;
}
/*!
Clears the list of arguments that are set for the process.
\sa setArguments() addArgument()
*/
void TQProcess::clearArguments()
{
_arguments.clear();
}
/*!
Sets \a args as the arguments for the process. The first element
in the list is the command to be executed. The other elements in
the list are the arguments to the command. Any previous arguments
are deleted.
TQProcess does not perform argument substitutions; for example, if you
specify "*" or "$DISPLAY", these values are passed to the process
literally. If you want to have the same behavior as the shell
provides, you must do the substitutions yourself; i.e. instead of
specifying a "*" you must specify the list of all the filenames in
the current directory, and instead of "$DISPLAY" you must specify
the value of the environment variable \c DISPLAY.
Note for Windows users. The standard Windows shells, e.g. \c
command.com and \c cmd.exe, do not perform file globbing, i.e.
they do not convert a "*" on the command line into a list of files
in the current directory. For this reason most Windows
applications implement their own file globbing, and as a result of
this, specifying an argument of "*" for a Windows application is
likely to result in the application performing a file glob and
ending up with a list of filenames.
\sa arguments() addArgument()
*/
void TQProcess::setArguments( const TQStringList& args )
{
_arguments = args;
}
/*!
Adds \a arg to the end of the list of arguments.
The first element in the list of arguments is the command to be
executed; the following elements are the command's arguments.
\sa arguments() setArguments()
*/
void TQProcess::addArgument( const TQString& arg )
{
_arguments.append( arg );
}
#ifndef TQT_NO_DIR
/*!
Returns the working directory that was set with
setWorkingDirectory(), or the current directory if none has been
explicitly set.
\sa setWorkingDirectory() TQDir::current()
*/
TQDir TQProcess::workingDirectory() const
{
return workingDir;
}
/*!
Sets \a dir as the working directory for processes. This does not
affect running processes; only processes that are started
afterwards are affected.
Setting the working directory is especially useful for processes
that try to access files with relative paths.
\sa workingDirectory() start()
*/
void TQProcess::setWorkingDirectory( const TQDir& dir )
{
workingDir = dir;
}
#endif //TQT_NO_DIR
/*!
Returns the communication required with the process, i.e. some
combination of the \c Communication flags.
\sa setCommunication()
*/
int TQProcess::communication() const
{
return comms;
}
/*!
Sets \a commFlags as the communication required with the process.
\a commFlags is a bitwise OR of the flags defined by the \c
Communication enum.
The default is \c{Stdin|Stdout|Stderr}.
\sa communication()
*/
void TQProcess::setCommunication( int commFlags )
{
comms = commFlags;
}
/*!
Returns TRUE if the process has exited normally; otherwise returns
FALSE. This implies that this function returns FALSE if the
process is still running.
\sa isRunning() exitStatus() processExited()
*/
bool TQProcess::normalExit() const
{
// isRunning() has the side effect that it determines the exit status!
if ( isRunning() )
return FALSE;
else
return exitNormal;
}
/*!
Returns the exit status of the process or 0 if the process is
still running. This function returns immediately and does not wait
until the process is finished.
If normalExit() is FALSE (e.g. if the program was killed or
crashed), this function returns 0, so you should check the return
value of normalExit() before relying on this value.
\sa normalExit() processExited()
*/
int TQProcess::exitStatus() const
{
// isRunning() has the side effect that it determines the exit status!
if ( isRunning() )
return 0;
else
return exitStat;
}
/*!
Reads the data that the process has written to standard output.
When new data is written to standard output, the class emits the
signal readyReadStdout().
If there is no data to read, this function returns a TQByteArray of
size 0: it does not wait until there is something to read.
\sa readyReadStdout() readLineStdout() readStderr() writeToStdin()
*/
TQByteArray TQProcess::readStdout()
{
if ( readStdoutCalled ) {
return TQByteArray();
}
readStdoutCalled = TRUE;
TQMembuf *buf = membufStdout();
readStdoutCalled = FALSE;
return buf->readAll();
}
/*!
Reads the data that the process has written to standard error.
When new data is written to standard error, the class emits the
signal readyReadStderr().
If there is no data to read, this function returns a TQByteArray of
size 0: it does not wait until there is something to read.
\sa readyReadStderr() readLineStderr() readStdout() writeToStdin()
*/
TQByteArray TQProcess::readStderr()
{
if ( readStderrCalled ) {
return TQByteArray();
}
readStderrCalled = TRUE;
TQMembuf *buf = membufStderr();
readStderrCalled = FALSE;
return buf->readAll();
}
/*!
Reads a line of text from standard output, excluding any trailing
newline or carriage return characters, and returns it. Returns
TQString::null if canReadLineStdout() returns FALSE.
By default, the text is interpreted to be in Latin-1 encoding. If you need
other codecs, you can set a different codec with
TQTextCodec::setCodecForCStrings().
\sa canReadLineStdout() readyReadStdout() readStdout() readLineStderr()
*/
TQString TQProcess::readLineStdout()
{
TQByteArray a( 256 );
TQMembuf *buf = membufStdout();
if ( !buf->scanNewline( &a ) ) {
if ( !canReadLineStdout() )
return TQString::null;
if ( !buf->scanNewline( &a ) )
return TQString( buf->readAll() );
}
uint size = a.size();
buf->consumeBytes( size, 0 );
// get rid of terminating \n or \r\n
if ( size>0 && a.at( size - 1 ) == '\n' ) {
if ( size>1 && a.at( size - 2 ) == '\r' )
a.at( size - 2 ) = '\0';
else
a.at( size - 1 ) = '\0';
}
return TQString( a );
}
/*!
Reads a line of text from standard error, excluding any trailing
newline or carriage return characters and returns it. Returns
TQString::null if canReadLineStderr() returns FALSE.
By default, the text is interpreted to be in Latin-1 encoding. If you need
other codecs, you can set a different codec with
TQTextCodec::setCodecForCStrings().
\sa canReadLineStderr() readyReadStderr() readStderr() readLineStdout()
*/
TQString TQProcess::readLineStderr()
{
TQByteArray a( 256 );
TQMembuf *buf = membufStderr();
if ( !buf->scanNewline( &a ) ) {
if ( !canReadLineStderr() )
return TQString::null;
if ( !buf->scanNewline( &a ) )
return TQString( buf->readAll() );
}
uint size = a.size();
buf->consumeBytes( size, 0 );
// get rid of terminating \n or \r\n
if ( size>0 && a.at( size - 1 ) == '\n' ) {
if ( size>1 && a.at( size - 2 ) == '\r' )
a.at( size - 2 ) = '\0';
else
a.at( size - 1 ) = '\0';
}
return TQString( a );
}
/*!
\fn void TQProcess::launchFinished()
This signal is emitted when the process was started with launch().
If the start was successful, this signal is emitted after all the
data has been written to standard input. If the start failed, then
this signal is emitted immediately.
This signal is especially useful if you want to know when you can
safely delete the TQProcess object when you are not interested in
reading from standard output or standard error.
\sa launch() TQObject::deleteLater()
*/
/*!
Runs the process and writes the data \a buf to the process's
standard input. If all the data is written to standard input,
standard input is closed. The command is searched for in the path
for executable programs; you can also use an absolute path in the
command itself.
If \a env is null, then the process is started with the same
environment as the starting process. If \a env is non-null, then
the values in the string list are interpreted as environment
setttings of the form \c {key=value} and the process is started
with these environment settings. For convenience, there is a small
exception to this rule under Unix: if \a env does not contain any
settings for the environment variable \c LD_LIBRARY_PATH, then
this variable is inherited from the starting process.
Returns TRUE if the process could be started; otherwise returns
FALSE.
Note that you should not use the slots writeToStdin() and
closeStdin() on processes started with launch(), since the result
is not well-defined. If you need these slots, use start() instead.
The process may or may not read the \a buf data sent to its
standard input.
You can call this function even when a process that was started
with this instance is still running. Be aware that if you do this
the standard input of the process that was launched first will be
closed, with any pending data being deleted, and the process will
be left to run out of your control. Similarly, if the process
could not be started the standard input will be closed and the
pending data deleted. (On operating systems that have zombie
processes, TQt will also wait() on the old process.)
The object emits the signal launchFinished() when this function
call is finished. If the start was successful, this signal is
emitted after all the data has been written to standard input. If
the start failed, then this signal is emitted immediately.
\sa start() launchFinished();
*/
bool TQProcess::launch( const TQByteArray& buf, TQStringList *env )
{
if ( start( env ) ) {
if ( !buf.isEmpty() ) {
connect( this, TQ_SIGNAL(wroteToStdin()),
this, TQ_SLOT(closeStdinLaunch()) );
writeToStdin( buf );
} else {
closeStdin();
emit launchFinished();
}
return TRUE;
} else {
emit launchFinished();
return FALSE;
}
}
/*!
\overload
The data \a buf is written to standard input with writeToStdin()
using the TQString::local8Bit() representation of the strings.
*/
bool TQProcess::launch( const TQString& buf, TQStringList *env )
{
if ( start( env ) ) {
if ( !buf.isEmpty() ) {
connect( this, TQ_SIGNAL(wroteToStdin()),
this, TQ_SLOT(closeStdinLaunch()) );
writeToStdin( buf );
} else {
closeStdin();
emit launchFinished();
}
return TRUE;
} else {
emit launchFinished();
return FALSE;
}
}
/*
This private slot is used by the launch() functions to close standard input.
*/
void TQProcess::closeStdinLaunch()
{
disconnect( this, TQ_SIGNAL(wroteToStdin()),
this, TQ_SLOT(closeStdinLaunch()) );
closeStdin();
emit launchFinished();
}
/*!
\fn void TQProcess::readyReadStdout()
This signal is emitted when the process has written data to
standard output. You can read the data with readStdout().
Note that this signal is only emitted when there is new data and
not when there is old, but unread data. In the slot connected to
this signal, you should always read everything that is available
at that moment to make sure that you don't lose any data.
\sa readStdout() readLineStdout() readyReadStderr()
*/
/*!
\fn void TQProcess::readyReadStderr()
This signal is emitted when the process has written data to
standard error. You can read the data with readStderr().
Note that this signal is only emitted when there is new data and
not when there is old, but unread data. In the slot connected to
this signal, you should always read everything that is available
at that moment to make sure that you don't lose any data.
\sa readStderr() readLineStderr() readyReadStdout()
*/
/*!
\fn void TQProcess::processExited()
This signal is emitted when the process has exited.
\sa isRunning() normalExit() exitStatus() start() launch()
*/
/*!
\fn void TQProcess::wroteToStdin()
This signal is emitted if the data sent to standard input (via
writeToStdin()) was actually written to the process. This does not
imply that the process really read the data, since this class only
detects when it was able to write the data to the operating
system. But it is now safe to close standard input without losing
pending data.
\sa writeToStdin() closeStdin()
*/
/*!
\overload
The string \a buf is handled as text using the
TQString::local8Bit() representation.
*/
void TQProcess::writeToStdin( const TQString& buf )
{
TQByteArray tmp = buf.local8Bit();
tmp.resize( tqstrlen( tmp.data() ) );
writeToStdin( tmp );
}
/*
* Under Windows the implementation is not so nice: it is not that easy to
* detect when one of the signals should be emitted; therefore there are some
* timers that query the information.
* To keep it a little efficient, use the timers only when they are needed.
* They are needed, if you are interested in the signals. So use
* connectNotify() and disconnectNotify() to keep track of your interest.
*/
/*! \reimp
*/
void TQProcess::connectNotify( const char * signal )
{
#if defined(QT_QPROCESS_DEBUG)
tqDebug( "TQProcess::connectNotify(): signal %s has been connected", signal );
#endif
if ( !ioRedirection )
if ( qstrcmp( signal, TQ_SIGNAL(readyReadStdout()) )==0 ||
qstrcmp( signal, TQ_SIGNAL(readyReadStderr()) )==0
) {
#if defined(QT_QPROCESS_DEBUG)
tqDebug( "TQProcess::connectNotify(): set ioRedirection to TRUE" );
#endif
setIoRedirection( TRUE );
return;
}
if ( !notifyOnExit && qstrcmp( signal, TQ_SIGNAL(processExited()) )==0 ) {
#if defined(QT_QPROCESS_DEBUG)
tqDebug( "TQProcess::connectNotify(): set notifyOnExit to TRUE" );
#endif
setNotifyOnExit( TRUE );
return;
}
if ( !wroteToStdinConnected && qstrcmp( signal, TQ_SIGNAL(wroteToStdin()) )==0 ) {
#if defined(QT_QPROCESS_DEBUG)
tqDebug( "TQProcess::connectNotify(): set wroteToStdinConnected to TRUE" );
#endif
setWroteStdinConnected( TRUE );
return;
}
}
/*! \reimp
*/
void TQProcess::disconnectNotify( const char * )
{
if ( ioRedirection &&
receivers( TQ_SIGNAL(readyReadStdout()) ) ==0 &&
receivers( TQ_SIGNAL(readyReadStderr()) ) ==0
) {
#if defined(QT_QPROCESS_DEBUG)
tqDebug( "TQProcess::disconnectNotify(): set ioRedirection to FALSE" );
#endif
setIoRedirection( FALSE );
}
if ( notifyOnExit && receivers( TQ_SIGNAL(processExited()) ) == 0 ) {
#if defined(QT_QPROCESS_DEBUG)
tqDebug( "TQProcess::disconnectNotify(): set notifyOnExit to FALSE" );
#endif
setNotifyOnExit( FALSE );
}
if ( wroteToStdinConnected && receivers( TQ_SIGNAL(wroteToStdin()) ) == 0 ) {
#if defined(QT_QPROCESS_DEBUG)
tqDebug( "TQProcess::disconnectNotify(): set wroteToStdinConnected to FALSE" );
#endif
setWroteStdinConnected( FALSE );
}
}
#endif // TQT_NO_PROCESS