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tdelibs/tdecore/kprocess.h

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/* This file is part of the KDE libraries
Copyright (C) 1997 Christian Czezakte (e9025461@student.tuwien.ac.at)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#ifndef __kprocess_h__
#define __kprocess_h__
#include <sys/types.h> // for pid_t
#include <sys/wait.h>
#include <signal.h>
#include <unistd.h>
#include <tqvaluelist.h>
#include <tqcstring.h>
#include <tqobject.h>
#include "tdelibs_export.h"
class TQSocketNotifier;
class TDEProcessPrivate;
#ifdef Q_OS_UNIX
#include <kpty.h>
#else
class KPty;
#endif
/**
* Child process invocation, monitoring and control.
* This class works only in the application's main thread.
*
* <b>General usage and features:</b>\n
*
* This class allows a KDE application to start child processes without having
* to worry about UN*X signal handling issues and zombie process reaping.
*
* @see KProcIO
*
* Basically, this class distinguishes three different ways of running
* child processes:
*
* @li DontCare -- The child process is invoked and both the child
* process and the parent process continue concurrently.
*
* The process is started in an own session (see setsid(2)).
*
* @li NotifyOnExit -- The child process is invoked and both the
* child and the parent process run concurrently.
*
* When the child process exits, the TDEProcess instance
* corresponding to it emits the Qt signal processExited().
* Since this signal is @em not emitted from within a UN*X
* signal handler, arbitrary function calls can be made.
*
* Be aware: When the TDEProcess object gets destructed, the child
* process will be killed if it is still running!
* This means in particular, that it usually makes no sense to use
* a TDEProcess on the stack with NotifyOnExit.
*
* @li OwnGroup -- like NotifyOnExit, but the child process is started
* in an own process group (and an own session, FWIW). The behavior of
* kill() changes to killing the whole process group - this makes
* this mode useful for implementing primitive job management. It can be
* used to work around broken wrapper scripts that don't propagate signals
* to the "real" program. However, use this with care, as you disturb the
* shell's job management if your program is started from the command line.
*
* @li Block -- The child process starts and the parent process
* is suspended until the child process exits. (@em Really not recommended
* for programs with a GUI.)
* In this mode the parent can read the child's output, but can't send it any
* input.
*
* TDEProcess also provides several functions for determining the exit status
* and the pid of the child process it represents.
*
* Furthermore it is possible to supply command-line arguments to the process
* in a clean fashion (no null-terminated stringlists and such...)
*
* A small usage example:
* \code
* TDEProcess *proc = new TDEProcess;
*
* *proc << "my_executable";
* *proc << "These" << "are" << "the" << "command" << "line" << "args";
* TQApplication::connect(proc, TQ_SIGNAL(processExited(TDEProcess *)),
* pointer_to_my_object, TQ_SLOT(my_objects_slot(TDEProcess *)));
* proc->start();
* \endcode
*
* This will start "my_executable" with the commandline arguments "These"...
*
* When the child process exits, the slot will be invoked.
*
* <b>Communication with the child process:</b>\n
*
* TDEProcess supports communication with the child process through
* stdin/stdout/stderr.
*
* The following functions are provided for getting data from the child
* process or sending data to the child's stdin (For more information,
* have a look at the documentation of each function):
*
* @li writeStdin()
* -- Transmit data to the child process' stdin. When all data was sent, the
* signal wroteStdin() is emitted.
*
* @li When data arrives at stdout or stderr, the signal receivedStdout()
* resp. receivedStderr() is emitted.
*
* @li You can shut down individual communication channels with
* closeStdin(), closeStdout(), and closeStderr(), resp.
*
* @author Christian Czezatke e9025461@student.tuwien.ac.at
*
**/
class TDECORE_EXPORT TDEProcess : public TQObject
{
TQ_OBJECT
public:
/**
* Modes in which the communication channel can be opened.
*
* If communication for more than one channel is required,
* the values have to be or'ed together, for example to get
* communication with stdout as well as with stdin, you would
* specify @p Stdin | @p Stdout
*
* If @p NoRead is specified in conjunction with @p Stdout,
* no data is actually read from @p Stdout but only
* the signal receivedStdout(int fd, int &len) is emitted.
*
* @p CTtyOnly tells setUsePty() to create a PTY for the process
* and make it the process' controlling TTY, but does not redirect
* any I/O channel to the PTY.
*
* If @p MergedStderr is specified in conjunction with @p Stdout,
* Stderr will be redirected onto the same file handle as Stdout,
* i.e., all error output will be signalled with receivedStdout().
* Don't specify @p Stderr if you specify @p MergedStderr.
*/
enum Communication {
NoCommunication = 0,
Stdin = 1, Stdout = 2, Stderr = 4,
AllOutput = 6, All = 7,
NoRead = 8,
CTtyOnly = NoRead,
MergedStderr = 16
};
/**
* Run-modes for a child process.
*/
enum RunMode {
/**
* The application does not receive notifications from the subprocess when
* it is finished or aborted.
*/
DontCare,
/**
* The application is notified when the subprocess dies.
*/
NotifyOnExit,
/**
* The application is suspended until the started process is finished.
*/
Block,
/**
* Same as NotifyOnExit, but the process is run in an own session,
* just like with DontCare.
*/
OwnGroup
};
/**
* Constructor
* @since 3.2
*/
TDEProcess( TQObject* parent, const char *name = 0 );
/**
* Constructor
*/ // KDE4 merge with the above
TDEProcess();
/**
*Destructor:
*
* If the process is running when the destructor for this class
* is called, the child process is killed with a SIGKILL, but
* only if the run mode is not of type @p DontCare.
* Processes started as @p DontCare keep running anyway.
*/
virtual ~TDEProcess();
/**
@deprecated
Use operator<<() instead.
Sets the executable to be started with this TDEProcess object.
Returns false if the process is currently running (in that
case the executable remains unchanged).
@see operator<<()
*/
bool setExecutable(const TQString& proc) TDE_DEPRECATED;
/**
* Sets the executable and the command line argument list for this process.
*
* For example, doing an "ls -l /usr/local/bin" can be achieved by:
* \code
* TDEProcess p;
* ...
* p << "ls" << "-l" << "/usr/local/bin"
* \endcode
*
* @param arg the argument to add
* @return a reference to this TDEProcess
**/
TDEProcess &operator<<(const TQString& arg);
/**
* Similar to previous method, takes a char *, supposed to be in locale 8 bit already.
*/
TDEProcess &operator<<(const char * arg);
/**
* Similar to previous method, takes a TQCString, supposed to be in locale 8 bit already.
* @param arg the argument to add
* @return a reference to this TDEProcess
*/
TDEProcess &operator<<(const TQCString & arg);
/**
* Sets the executable and the command line argument list for this process,
* in a single method call, or add a list of arguments.
* @param args the arguments to add
* @return a reference to this TDEProcess
**/
TDEProcess &operator<<(const TQStringList& args);
/**
* Clear a command line argument list that has been set by using
* operator<<.
*/
void clearArguments();
/**
* Starts the process.
* For a detailed description of the
* various run modes and communication semantics, have a look at the
* general description of the TDEProcess class. Note that if you use
* setUsePty( Stdout | Stderr, \<bool\> ), you cannot use Stdout | Stderr
* here - instead, use Stdout only to receive the mixed output.
*
* The following problems could cause this function to
* return false:
*
* @li The process is already running.
* @li The command line argument list is empty.
* @li The the @p comm parameter is incompatible with the selected pty usage.
* @li The starting of the process failed (could not fork).
* @li The executable was not found.
*
* @param runmode The Run-mode for the process.
* @param comm Specifies which communication links should be
* established to the child process (stdin/stdout/stderr). By default,
* no communication takes place and the respective communication
* signals will never get emitted.
*
* @return true on success, false on error
* (see above for error conditions)
**/
virtual bool start(RunMode runmode = NotifyOnExit,
Communication comm = NoCommunication);
/**
* Stop the process (by sending it a signal).
*
* @param signo The signal to send. The default is SIGTERM.
* @return true if the signal was delivered successfully.
*/
virtual bool kill(int signo = SIGTERM);
/**
* Checks whether the process is running.
* @return true if the process is (still) considered to be running
*/
bool isRunning() const;
/** Returns the process id of the process.
*
* If it is called after
* the process has exited, it returns the process id of the last
* child process that was created by this instance of TDEProcess.
*
* Calling it before any child process has been started by this
* TDEProcess instance causes pid() to return 0.
* @return the pid of the process or 0 if no process has been started yet.
**/
pid_t pid() const;
/**
* @deprecated
* Use pid() instead.
*/
TDE_DEPRECATED pid_t getPid() const { return pid(); }
/**
* Suspend processing of data from stdout of the child process.
*/
void suspend();
/**
* Resume processing of data from stdout of the child process.
*/
void resume();
/**
* Suspend execution of the current thread until the child process dies
* or the timeout hits. This function is not recommended for programs
* with a GUI.
* @param timeout timeout in seconds. -1 means wait indefinitely.
* @return true if the process exited, false if the timeout hit.
* @since 3.2
*/
bool wait(int timeout = -1);
/**
* Checks whether the process exited cleanly.
*
* @return true if the process has already finished and has exited
* "voluntarily", ie: it has not been killed by a signal.
*/
bool normalExit() const;
/**
* Checks whether the process was killed by a signal.
*
* @return true if the process has already finished and has not exited
* "voluntarily", ie: it has been killed by a signal.
*
* @since 3.2
*/
bool signalled() const;
/**
* Checks whether a killed process dumped core.
*
* @return true if signalled() returns true and the process
* dumped core. Note that on systems that don't define the
* WCOREDUMP macro, the return value is always false.
*
* @since 3.2
*/
bool coreDumped() const;
/**
* Returns the exit status of the process.
*
* @return the exit status of the process. Note that this value
* is not valid if normalExit() returns false.
*/
int exitStatus() const;
/**
* Returns the signal the process was killed by.
*
* @return the signal number that caused the process to exit.
* Note that this value is not valid if signalled() returns false.
*
* @since 3.2
*/
int exitSignal() const;
/**
* Transmit data to the child process' stdin.
*
* This function may return false in the following cases:
*
* @li The process is not currently running.
* This implies that you cannot use this function in Block mode.
*
* @li Communication to stdin has not been requested in the start() call.
*
* @li Transmission of data to the child process by a previous call to
* writeStdin() is still in progress.
*
* Please note that the data is sent to the client asynchronously,
* so when this function returns, the data might not have been
* processed by the child process.
* That means that you must not free @p buffer or call writeStdin()
* again until either a wroteStdin() signal indicates that the
* data has been sent or a processExited() signal shows that
* the child process is no longer alive.
*
* If all the data has been sent to the client, the signal
* wroteStdin() will be emitted.
*
* This function does not work when the process is start()ed in Block mode.
*
* @param buffer the buffer to write
* @param buflen the length of the buffer
* @return false if an error has occurred
**/
bool writeStdin(const char *buffer, int buflen);
/**
* Shuts down the Stdin communication link. If no pty is used, this
* causes "EOF" to be indicated on the child's stdin file descriptor.
*
* @return false if no Stdin communication link exists (any more).
*/
bool closeStdin();
/**
* Shuts down the Stdout communication link. If no pty is used, any further
* attempts by the child to write to its stdout file descriptor will cause
* it to receive a SIGPIPE.
*
* @return false if no Stdout communication link exists (any more).
*/
bool closeStdout();
/**
* Shuts down the Stderr communication link. If no pty is used, any further
* attempts by the child to write to its stderr file descriptor will cause
* it to receive a SIGPIPE.
*
* @return false if no Stderr communication link exists (any more).
*/
bool closeStderr();
/**
* Deletes the optional utmp entry and closes the pty.
*
* Make sure to shut down any communication links that are using the pty
* before calling this function.
*
* @return false if the pty is not open (any more).
*/
bool closePty();
/**
* @brief Close stdin, stdout, stderr and the pty
*
* This is the same that calling all close* functions in a row:
* @see closeStdin, @see closeStdout, @see closeStderr and @see closePty
*/
void closeAll();
/**
* Lets you see what your arguments are for debugging.
* @return the list of arguments
*/
const TQValueList<TQCString> &args() /* const */ { return arguments; }
/**
* Controls whether the started process should drop any
* setuid/setgid privileges or whether it should keep them.
* Note that this function is mostly a dummy, as the KDE libraries
* currently refuse to run with setuid/setgid privileges.
*
* The default is false: drop privileges
* @param keepPrivileges true to keep the privileges
*/
void setRunPrivileged(bool keepPrivileges);
/**
* Returns whether the started process will drop any
* setuid/setgid privileges or whether it will keep them.
* @return true if the process runs privileged
*/
bool runPrivileged() const;
/**
* Adds the variable @p name to the process' environment.
* This function must be called before starting the process.
* @param name the name of the environment variable
* @param value the new value for the environment variable
*/
void setEnvironment(const TQString &name, const TQString &value);
/**
* Changes the current working directory (CWD) of the process
* to be started.
* This function must be called before starting the process.
* @param dir the new directory
*/
void setWorkingDirectory(const TQString &dir);
/**
* Specify whether to start the command via a shell or directly.
* The default is to start the command directly.
* If @p useShell is true @p shell will be used as shell, or
* if shell is empty, /bin/sh will be used.
*
* When using a shell, the caller should make sure that all filenames etc.
* are properly quoted when passed as argument.
* @see quote()
* @param useShell true if the command should be started via a shell
* @param shell the path to the shell that will execute the process, or
* 0 to use /bin/sh. Use getenv("SHELL") to use the user's
* default shell, but note that doing so is usually a bad idea
* for shell compatibility reasons.
* @since 3.1
*/
void setUseShell(bool useShell, const char *shell = 0);
/**
* This function can be used to quote an argument string such that
* the shell processes it properly. This is e. g. necessary for
* user-provided file names which may contain spaces or quotes.
* It also prevents expansion of wild cards and environment variables.
* @param arg the argument to quote
* @return the quoted argument
* @since 3.1
*/
static TQString quote(const TQString &arg);
/**
* Detaches TDEProcess from child process. All communication is closed.
* No exit notification is emitted any more for the child process.
* Deleting the TDEProcess will no longer kill the child process.
* Note that the current process remains the parent process of the
* child process.
*/
void detach();
#ifdef Q_OS_UNIX
/**
* Specify whether to create a pty (pseudo-terminal) for running the
* command.
* This function should be called before starting the process.
*
* @param comm for which stdio handles to use a pty. Note that it is not
* allowed to specify Stdout and Stderr at the same time both here and to
* start (there is only one pty, so they cannot be distinguished).
* @param addUtmp true if a utmp entry should be created for the pty
* @since 3.2
*/
void setUsePty(Communication comm, bool addUtmp);
/**
* Obtains the pty object used by this process. The return value is
* valid only after setUsePty() was used with a non-zero argument.
* The pty is open only while the process is running.
* @return a pointer to the pty object
* @since 3.2
*/
KPty *pty() const;
#endif
/**
* More or less intuitive constants for use with setPriority().
*/
enum { PrioLowest = 20, PrioLow = 10, PrioLower = 5, PrioNormal = 0,
PrioHigher = -5, PrioHigh = -10, PrioHighest = -19 };
/**
* Sets the scheduling priority of the process.
* @param prio the new priority in the range -20 (high) to 19 (low).
* @return false on error; see setpriority(2) for possible reasons.
* @since 3.2
*/
bool setPriority(int prio);
signals:
/**
* Emitted after the process has terminated when
* the process was run in the @p NotifyOnExit (==default option to
* start() ) or the Block mode.
* @param proc a pointer to the process that has exited
**/
void processExited(TDEProcess *proc);
/**
* Emitted, when output from the child process has
* been received on stdout.
*
* To actually get this signal, the Stdout communication link
* has to be turned on in start().
*
* @param proc a pointer to the process that has received the output
* @param buffer The data received.
* @param buflen The number of bytes that are available.
*
* You should copy the information contained in @p buffer to your private
* data structures before returning from the slot.
* Example:
* \code
* TQString myBuf = TQString::fromLatin1(buffer, buflen);
* \endcode
**/
void receivedStdout(TDEProcess *proc, char *buffer, int buflen);
/**
* Emitted when output from the child process has
* been received on stdout.
*
* To actually get this signal, the Stdout communication link
* has to be turned on in start() and the
* NoRead flag must have been passed.
*
* You will need to explicitly call resume() after your call to start()
* to begin processing data from the child process' stdout. This is
* to ensure that this signal is not emitted when no one is connected
* to it, otherwise this signal will not be emitted.
*
* The data still has to be read from file descriptor @p fd.
* @param fd the file descriptor that provides the data
* @param len the number of bytes that have been read from @p fd must
* be written here
**/
void receivedStdout(int fd, int &len); // KDE4: change, broken API
/**
* Emitted, when output from the child process has
* been received on stderr.
*
* To actually get this signal, the Stderr communication link
* has to be turned on in start().
*
* You should copy the information contained in @p buffer to your private
* data structures before returning from the slot.
*
* @param proc a pointer to the process that has received the data
* @param buffer The data received.
* @param buflen The number of bytes that are available.
**/
void receivedStderr(TDEProcess *proc, char *buffer, int buflen);
/**
* Emitted after all the data that has been
* specified by a prior call to writeStdin() has actually been
* written to the child process.
* @param proc a pointer to the process
**/
void wroteStdin(TDEProcess *proc);
protected slots:
/**
* This slot gets activated when data from the child's stdout arrives.
* It usually calls childOutput().
* @param fdno the file descriptor for the output
*/
void slotChildOutput(int fdno);
/**
* This slot gets activated when data from the child's stderr arrives.
* It usually calls childError().
* @param fdno the file descriptor for the output
*/
void slotChildError(int fdno);
/**
* Called when another bulk of data can be sent to the child's
* stdin. If there is no more data to be sent to stdin currently
* available, this function must disable the TQSocketNotifier innot.
* @param dummy ignore this argument
*/
void slotSendData(int dummy); // KDE 4: remove dummy
protected:
/**
* Sets up the environment according to the data passed via
* setEnvironment()
*/
void setupEnvironment();
/**
* The list of the process' command line arguments. The first entry
* in this list is the executable itself.
*/
TQValueList<TQCString> arguments;
/**
* How to run the process (Block, NotifyOnExit, DontCare). You should
* not modify this data member directly from derived classes.
*/
RunMode run_mode;
/**
* true if the process is currently running. You should not
* modify this data member directly from derived classes. Please use
* isRunning() for reading the value of this data member since it
* will probably be made private in later versions of TDEProcess.
*/
bool runs;
/**
* The PID of the currently running process.
* You should not modify this data member in derived classes.
* Please use pid() instead of directly accessing this
* member since it will probably be made private in
* later versions of TDEProcess.
*/
pid_t pid_;
/**
* The process' exit status as returned by waitpid(). You should not
* modify the value of this data member from derived classes. You should
* rather use exitStatus() than accessing this data member directly
* since it will probably be made private in further versions of
* TDEProcess.
*/
int status;
/**
* If false, the child process' effective uid & gid will be reset to the
* real values.
* @see setRunPrivileged()
*/
bool keepPrivs;
/**
* This function is called from start() right before a fork() takes
* place. According to the @p comm parameter this function has to initialize
* the in, out and err data members of TDEProcess.
*
* This function should return 1 if setting the needed communication channels
* was successful.
*
* The default implementation is to create UNIX STREAM sockets for the
* communication, but you could reimplement this function to establish a
* TCP/IP communication for network communication, for example.
*/
virtual int setupCommunication(Communication comm);
/**
* Called right after a (successful) fork() on the parent side. This function
* will usually do some communications cleanup, like closing in[0],
* out[1] and out[1].
*
* Furthermore, it must also create the TQSocketNotifiers innot,
* outnot and errnot and connect their Qt signals to the respective
* TDEProcess slots.
*
* For a more detailed explanation, it is best to have a look at the default
* implementation in kprocess.cpp.
*/
virtual int commSetupDoneP();
/**
* Called right after a (successful) fork(), but before an exec() on the child
* process' side. It usually duplicates the in[0], out[1] and
* err[1] file handles to the respective standard I/O handles.
*/
virtual int commSetupDoneC();
/**
* Immediately called after a successfully started process in NotifyOnExit
* mode has exited. This function normally calls commClose()
* and emits the processExited() signal.
* @param state the exit code of the process as returned by waitpid()
*/
virtual void processHasExited(int state);
/**
* Cleans up the communication links to the child after it has exited.
* This function should act upon the values of pid() and runs.
* See the kprocess.cpp source for details.
* @li If pid() returns zero, the communication links should be closed
* only.
* @li if pid() returns non-zero and runs is false, all data
* immediately available from the communication links should be processed
* before closing them.
* @li if pid() returns non-zero and runs is true, the communication
* links should be monitored for data until the file handle returned by
* TDEProcessController::theTDEProcessController->notifierFd() becomes ready
* for reading - when it triggers, runs should be reset to false, and
* the function should be immediately left without closing anything.
*
* The previous semantics of this function are forward-compatible, but should
* be avoided, as they are prone to race conditions and can cause TDEProcess
* (and thus the whole program) to lock up under certain circumstances. At the
* end the function closes the communication links in any case. Additionally
* @li if runs is true, the communication links are monitored for data
* until all of them have returned EOF. Note that if any system function is
* interrupted (errno == EINTR) the polling loop should be aborted.
* @li if runs is false, all data immediately available from the
* communication links is processed.
*/
virtual void commClose();
/* KDE 4 - commClose will be changed to perform cleanup only in all cases *
* If @p notfd is -1, all data immediately available from the
* communication links should be processed.
* If @p notfd is not -1, the communication links should be monitored
* for data until the file handle @p notfd becomes ready for reading.
*/
// virtual void commDrain(int notfd);
/**
* Specify the actual executable that should be started (first argument to execve)
* Normally the the first argument is the executable but you can
* override that with this function.
*/
void setBinaryExecutable(const char *filename);
/**
* The socket descriptors for stdout.
*/
int out[2];
/**
* The socket descriptors for stdin.
*/
int in[2];
/**
* The socket descriptors for stderr.
*/
int err[2];
/**
* The socket notifier for in[1].
*/
TQSocketNotifier *innot;
/**
* The socket notifier for out[0].
*/
TQSocketNotifier *outnot;
/**
* The socket notifier for err[0].
*/
TQSocketNotifier *errnot;
/**
* Lists the communication links that are activated for the child
* process. Should not be modified from derived classes.
*/
Communication communication;
/**
* Called by slotChildOutput() this function copies data arriving from
* the child process' stdout to the respective buffer and emits the signal
* receivedStdout().
*/
int childOutput(int fdno);
/**
* Called by slotChildError() this function copies data arriving from
* the child process' stderr to the respective buffer and emits the signal
* receivedStderr().
*/
int childError(int fdno);
/**
* The buffer holding the data that has to be sent to the child
*/
const char *input_data;
/**
* The number of bytes already transmitted
*/
int input_sent;
/**
* The total length of input_data
*/
int input_total;
/**
* TDEProcessController is a friend of TDEProcess because it has to have
* access to various data members.
*/
friend class TDEProcessController;
protected:
virtual void virtual_hook( int id, void* data );
private:
TDEProcessPrivate *d;
};
class KShellProcessPrivate;
/**
* @obsolete
*
* Use TDEProcess and TDEProcess::setUseShell(true) instead.
*
* @short A class derived from TDEProcess to start child
* processes through a shell.
* @author Christian Czezatke <e9025461@student.tuwien.ac.at>
*/
class TDECORE_EXPORT KShellProcess: public TDEProcess
{
TQ_OBJECT
public:
/**
* Constructor
*
* If no shellname is specified, the user's default shell is used.
*/
KShellProcess(const char *shellname=0);
/**
* Destructor.
*/
~KShellProcess();
virtual bool start(RunMode runmode = NotifyOnExit,
Communication comm = NoCommunication);
static TQString quote(const TQString &arg);
private:
TQCString shell;
protected:
virtual void virtual_hook( int id, void* data );
private:
KShellProcessPrivate *d;
};
#endif