/*                 This file is part of the Opie Project             Copyright (C) 2003-2004 Holger Freyther Copyright (C) The Opie Team =. Based on KProcess (C) 1997 Christian Czezatke (e9025461@student.tuwien.ac.at) .=l.          .>+-= _;:,     .>    :=|. This program is free software; you can .> <`_,   >  .   <= redistribute it and/or modify it under :`=1 )Y*s>-.--   : the terms of the GNU Library General Public .="- .-=="i,     .._ License as published by the Free Software - .   .-<_>     .<> Foundation; either version 2 of the License,    ._= =}       : or (at your option) any later version.   .%`+i>       _;_.   .i_,=:_.      -`: 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifndef OPROCESS_H #define OPROCESS_H /* QT */ #include #include #include /* STD */ #include // for pid_t #include #include #include class QSocketNotifier; namespace Opie { namespace Core { namespace Internal { class OProcessController; class OProcessPrivate; } /** * Child process invocation, monitoring and control. * * @par General usage and features * *This class allows a KDE and OPIE 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 OProcess::DontCare -- The child process is invoked and both the child *process and the parent process continue concurrently. * *Starting a DontCare child process means that the application is *not interested in any notification to determine whether the *child process has already exited or not. * *@li OProcess::NotifyOnExit -- The child process is invoked and both the *child and the parent process run concurrently. * *When the child process exits, the OProcess instance *corresponding to it emits the Qt signal @ref 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 OProcess objects gets destructed, the child *process will be killed if it is still running! *This means in particular, that you cannot use a OProcess on the stack *with OProcess::NotifyOnExit. * *@li OProcess::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.) * *OProcess 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: *
 *OProcess *proc = new OProcess;
 *
 **proc << "my_executable";
 **proc << "These" << "are" << "the" << "command" << "line" << "args";
 *QObject::connect(proc, SIGNAL(processExited(Opie::Core::OProcess *)),
 *                 pointer_to_my_object, SLOT(my_objects_slot(Opie::Core::OProcess *)));
 *proc->start();
 *
* *This will start "my_executable" with the commandline arguments "These"... * *When the child process exits, the respective Qt signal will be emitted. * *@par Communication with the child process * *OProcess 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 bool @ref writeStdin(char *buffer, int buflen); *@li -- Transmit data to the child process's stdin. * *@li bool @ref closeStdin(); *@li -- Closes the child process's stdin (which causes it to see an feof(stdin)). *Returns false if you try to close stdin for a process that has been started *without a communication channel to stdin. * *@li bool @ref closeStdout(); *@li -- Closes the child process's stdout. *Returns false if you try to close stdout for a process that has been started *without a communication channel to stdout. * *@li bool @ref closeStderr(); *@li -- Closes the child process's stderr. *Returns false if you try to close stderr for a process that has been started *without a communication channel to stderr. * * *@par QT signals: * *@li void @ref receivedStdout(OProcess *proc, char *buffer, int buflen); *@li void @ref receivedStderr(OProcess *proc, char *buffer, int buflen); *@li -- Indicates that new data has arrived from either the *child process's stdout or stderr. * *@li void @ref wroteStdin(OProcess *proc); *@li -- Indicates that all data that has been sent to the child process *by a prior call to @ref writeStdin() has actually been transmitted to the *client . * *@author Christian Czezakte e9025461@student.tuwien.ac.at *@author Holger Freyther (Opie Port) * **/ class OProcess : public QObject { Q_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 | @p Stdout * * If @p NoRead is specified in conjunction with @p Stdout, * no data is actually read from @p Stdout but only * the signal @ref childOutput(int fd) is emitted. */ enum Communication { NoCommunication = 0, Stdin = 1, Stdout = 2, Stderr = 4, AllOutput = 6, All = 7, NoRead }; /** * 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 }; /** * Constructor */ OProcess( QObject *parent = 0, const char *name = 0 ); /** * Constructor */ OProcess( const QString &arg0, QObject *parent = 0, const char *name = 0 ); /** * Constructor */ OProcess( const QStringList &args, QObject *parent = 0, const char *name = 0 ); /** *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 ~OProcess(); /** @deprecated The use of this function is now deprecated. -- Please use the "operator<<" instead of "setExecutable". Sets the executable to be started with this OProcess object. Returns false if the process is currently running (in that case the executable remains unchanged.) @see operator<< */ bool setExecutable( const QString& proc ); /** * 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: *
     *  OProcess p;
     *  ...
     *  p << "ls" << "-l" << "/usr/local/bin"
     *  
* **/ OProcess &operator<<( const QString& arg ); /** * Similar to previous method, takes a char *, supposed to be in locale 8 bit already. */ OProcess &operator<<( const char * arg ); /** * Similar to previous method, takes a QCString, supposed to be in locale 8 bit already. */ OProcess &operator<<( const QCString & arg ); /** * Sets the executable and the command line argument list for this process, * in a single method call, or add a list of arguments. **/ OProcess &operator<<( const QStringList& args ); /** * Clear a command line argument list that has been set by using * the "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 OProcess class. * * 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 starting of the process failed (could not fork). * @li The executable was not found. * * @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 @p true if the signal was delivered successfully. */ virtual bool kill( int signo = SIGTERM ); /** @return @p 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 OProcess. * * Calling it before any child process has been started by this * OProcess instance causes pid() to return 0. **/ pid_t pid() const; /** * Suspend processing of data from stdout of the child process. */ void suspend(); /** * Resume processing of data from stdout of the child process. */ void resume(); /** * @return @p true if the process has already finished and has exited * "voluntarily", ie: it has not been killed by a signal. * * Note that you should check @ref OProcess::exitStatus() to determine * whether the process completed its task successful or not. */ bool normalExit() const; /** * Returns the exit status of the process. * * Please use * @ref OProcess::normalExit() to check whether the process has exited * cleanly (i.e., @ref OProcess::normalExit() returns @p true) before calling * this function because if the process did not exit normally, * it does not have a valid exit status. */ int exitStatus() const; /** * Transmit data to the child process's stdin. * * OProcess::writeStdin may return false in the following cases: * * @li The process is not currently running. * * @li Communication to stdin has not been requested in the @ref start() call. * * @li Transmission of data to the child process by a previous call to * @ref 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. * * If all the data has been sent to the client, the signal * @ref wroteStdin() will be emitted. * * Please note that you must not free "buffer" or call @ref writeStdin() * again until either a @ref wroteStdin() signal indicates that the * data has been sent or a @ref processHasExited() signal shows that * the child process is no longer alive... **/ bool writeStdin( const char *buffer, int buflen ); void flushStdin(); /** * This causes the stdin file descriptor of the child process to be * closed indicating an "EOF" to the child. * * @return @p false if no communication to the process's stdin * had been specified in the call to @ref start(). */ bool closeStdin(); /** * This causes the stdout file descriptor of the child process to be * closed. * * @return @p false if no communication to the process's stdout * had been specified in the call to @ref start(). */ bool closeStdout(); /** * This causes the stderr file descriptor of the child process to be * closed. * * @return @p false if no communication to the process's stderr * had been specified in the call to @ref start(). */ bool closeStderr(); /** * Lets you see what your arguments are for debugging. * \todo make const */ const QValueList &args() { return arguments; } /** * Controls whether the started process should drop any * setuid/segid privileges or whether it should keep them * * The default is @p false : drop privileges */ void setRunPrivileged( bool keepPrivileges ); /** * Returns whether the started process will drop any * setuid/segid privileges or whether it will keep them */ bool runPrivileged() const; /** * Modifies the environment of the process to be started. * This function must be called before starting the process. */ void setEnvironment( const QString &name, const QString &value ); /** * Changes the current working directory (CWD) of the process * to be started. * This function must be called before starting the process. */ void setWorkingDirectory( const QString &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, the standard shell is used. * @p quote A flag indicating whether to quote the arguments. * * When using a shell, the caller should make sure that all filenames etc. * are properly quoted when passed as argument. * @see quote() */ 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. */ static QString quote( const QString &arg ); /** * Detaches OProcess from child process. All communication is closed. * No exit notification is emitted any more for the child process. * Deleting the OProcess will no longer kill the child process. * Note that the current process remains the parent process of the * child process. */ void detach(); /** * @return the PID of @a process, or -1 if the process is not running */ static int processPID( const QString& process ); signals: /** * Emitted after the process has terminated when * the process was run in the @p NotifyOnExit (==default option to * @ref start()) or the @ref Block mode. **/ void processExited( Opie::Core::OProcess *proc ); /** * Emitted, when output from the child process has * been received on stdout. * * To actually get * these signals, the respective communication link (stdout/stderr) * has to be turned on in @ref start(). * * @param proc The process * @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 this slot. **/ void receivedStdout( Opie::Core::OProcess *proc, char *buffer, int buflen ); /** * Emitted when output from the child process has * been received on stdout. * * To actually get these signals, the respective communications link * (stdout/stderr) has to be turned on in @ref start() and the * @p NoRead flag should have been passed. * * You will need to explicitly call resume() after your call to start() * to begin processing data from the child process's 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. **/ void receivedStdout( int fd, int &len ); /** * Emitted, when output from the child process has * been received on stderr. * To actually get * these signals, the respective communication link (stdout/stderr) * has to be turned on in @ref start(). * * @param proc The process * @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 this slot. */ void receivedStderr( Opie::Core::OProcess *proc, char *buffer, int buflen ); /** * Emitted after all the data that has been * specified by a prior call to @ref writeStdin() has actually been * written to the child process. **/ void wroteStdin( Opie::Core::OProcess *proc ); protected slots: /** * This slot gets activated when data from the child's stdout arrives. * It usually calls "childOutput" */ void slotChildOutput( int fdno ); /** * This slot gets activated when data from the child's stderr arrives. * It usually calls "childError" */ void slotChildError( int fdno ); /* Slot functions for capturing stdout and stderr of the child */ /** * 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 QSocketNotifier "innot". */ void slotSendData( int 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. */ QValueList 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. For * reading the value of this data member, please use "isRunning()" * since "runs" will probably be made private in later versions * of OProcess. */ bool runs; /** * The PID of the currently running process (see "getPid()"). * You should not modify this data member in derived classes. * Please use "getPid()" instead of directly accessing this * member function since it will probably be made private in * later versions of OProcess. */ 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 @ref exitStatus than accessing this data member directly * since it will probably be made private in further versions of * OProcess. */ int status; /** * See setRunPrivileged() */ bool keepPrivs; /* Functions for setting up the sockets for communication. setupCommunication -- is called from "start" before "fork"ing. commSetupDoneP -- completes communication socket setup in the parent commSetupDoneC -- completes communication setup in the child process commClose -- frees all allocated communication resources in the parent after the process has exited */ /** * This function is called from "OProcess::start" right before a "fork" takes * place. According to * the "comm" parameter this function has to initialize the "in", "out" and * "err" data member of OProcess. * * This function should return 0 if setting the needed communication channels * was successful. * * The default implementation is to create UNIX STREAM sockets for the communication, * but you could overload this function and 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 the reading end * of the "stdin" communication channel. * * Furthermore, it must also create the QSocketNotifiers "innot", "outnot" and * "errnot" and connect their Qt slots to the respective OProcess member functions. * * For a more detailed explanation, it is best to have a look at the default * implementation of "setupCommunication" in kprocess.cpp. */ virtual int commSetupDoneP(); /** * Called right after a (successful) fork, but before an "exec" on the child * process' side. It usually just closes the unused communication ends of * "in", "out" and "err" (like the writing end of the "in" communication * channel. */ virtual int commSetupDoneC(); /** * Immediately called after a process has exited. This function normally * calls commClose to close all open communication channels to this * process and emits the "processExited" signal (if the process was * not running in the "DontCare" mode). */ virtual void processHasExited( int state ); /** * Should clean up the communication links to the child after it has * exited. Should be called from "processHasExited". */ virtual void commClose(); /** * the socket descriptors for stdin/stdout/stderr. */ int out[ 2 ]; int in[ 2 ]; int err[ 2 ]; /** * The socket notifiers for the above socket descriptors. */ QSocketNotifier *innot; QSocketNotifier *outnot; QSocketNotifier *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's stdout to the respective buffer and emits the signal * "@ref receivedStderr". */ int childOutput( int fdno ); /** * Called by "slotChildOutput" this function copies data arriving from the * child process's stdout to the respective buffer and emits the signal * "@ref receivedStderr" */ int childError( int fdno ); // information about the data that has to be sent to the child: const char *input_data; // the buffer holding the data int input_sent; // # of bytes already transmitted int input_total; // total length of input_data /** * @ref OProcessController is a friend of OProcess because it has to have * access to various data members. */ friend class Internal::OProcessController; private: /** * Searches for a valid shell. * Here is the algorithm used for finding an executable shell: * * @li Try the executable pointed to by the "SHELL" environment * variable with white spaces stripped off * * @li If your process runs with uid != euid or gid != egid, a shell * not listed in /etc/shells will not used. * * @li If no valid shell could be found, "/bin/sh" is used as a last resort. */ QCString searchShell(); /** * Used by @ref searchShell in order to find out whether the shell found * is actually executable at all. */ bool isExecutable( const QCString &filename ); // Disallow assignment and copy-construction OProcess( const OProcess& ); OProcess& operator= ( const OProcess& ); private: void init ( ); Internal::OProcessPrivate *d; }; } } #endif