KDE3Support
#include <k3process.h>
Public Types | |
enum | { PrioLowest = 20, PrioLow = 10, PrioLower = 5, PrioNormal = 0, PrioHigher = -5, PrioHigh = -10, PrioHighest = -19 } |
enum | CommunicationFlag { NoCommunication = 0, Stdin = 1, Stdout = 2, Stderr = 4, AllOutput = 6, All = 7, NoRead = 8, CTtyOnly = NoRead, MergedStderr = 16 } |
enum | RunMode { DontCare, NotifyOnExit, Block, OwnGroup } |
Signals | |
void | processExited (K3Process *proc) |
void | receivedStderr (K3Process *proc, char *buffer, int buflen) |
void | receivedStdout (K3Process *proc, char *buffer, int buflen) |
void | receivedStdout (int fd, int &len) |
void | wroteStdin (K3Process *proc) |
Public Member Functions | |
K3Process (QObject *parent=0L) | |
virtual | ~K3Process () |
const QList< QByteArray > & | args () |
void | clearArguments () |
void | closeAll () |
bool | closePty () |
bool | closeStderr () |
bool | closeStdin () |
bool | closeStdout () |
bool | coreDumped () const |
void | detach () |
int | exitSignal () const |
int | exitStatus () const |
bool | isRunning () const |
virtual bool | kill (int signo=SIGTERM) |
bool | normalExit () const |
K3Process & | operator<< (const QString &arg) |
K3Process & | operator<< (const char *arg) |
K3Process & | operator<< (const QByteArray &arg) |
K3Process & | operator<< (const QStringList &args) |
pid_t | pid () const |
KPty * | pty () const |
void | resume () |
bool | runPrivileged () const |
void | setEnvironment (const QString &name, const QString &value) |
bool | setPriority (int prio) |
void | setRunPrivileged (bool keepPrivileges) |
void | setUsePty (Communication comm, bool addUtmp) |
void | setUseShell (bool useShell, const char *shell=0) |
void | setWorkingDirectory (const QString &dir) |
bool | signalled () const |
virtual bool | start (RunMode runmode=NotifyOnExit, Communication comm=NoCommunication) |
void | suspend () |
bool | wait (int timeout=-1) |
bool | writeStdin (const char *buffer, int buflen) |
Static Public Member Functions | |
static QString | quote (const QString &arg) |
Protected Slots | |
void | slotChildError (int fdno) |
void | slotChildOutput (int fdno) |
void | slotSendData (int dummy) |
Protected Member Functions | |
int | childError (int fdno) |
int | childOutput (int fdno) |
virtual void | commClose () |
virtual int | commSetupDoneC () |
virtual int | commSetupDoneP () |
virtual void | processHasExited (int state) |
void | setBinaryExecutable (const char *filename) |
virtual int | setupCommunication (Communication comm) |
void | setupEnvironment () |
Protected Attributes | |
QList< QByteArray > | arguments |
Communication | communication |
int | err [2] |
QSocketNotifier * | errnot |
int | in [2] |
QSocketNotifier * | innot |
const char * | input_data |
int | input_sent |
int | input_total |
bool | keepPrivs |
int | out [2] |
QSocketNotifier * | outnot |
pid_t | pid_ |
RunMode | run_mode |
bool | runs |
int | status |
Detailed Description
- Deprecated:
- Use KProcess and KPtyProcess instead.
Child process invocation, monitoring and control. This class works only in the application's main thread.
General usage and features:
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 also
- K3ProcIO
Basically, this class distinguishes three different ways of running child processes:
- 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)).
- NotifyOnExit – The child process is invoked and both the child and the parent process run concurrently.
When the child process exits, the K3Process instance corresponding to it emits the Qt signal processExited(). Since this signal is not emitted from within a UN*X signal handler, arbitrary function calls can be made.
Be aware: When the K3Process 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 K3Process on the stack with NotifyOnExit.
- 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.
- Block – The child process starts and the parent process is suspended until the child process exits. (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.
K3Process 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:
This will start "my_executable" with the commandline arguments "These"...
When the child process exits, the slot will be invoked.
Communication with the child process:
K3Process 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):
- writeStdin() – Transmit data to the child process' stdin. When all data was sent, the signal wroteStdin() is emitted.
- When data arrives at stdout or stderr, the signal receivedStdout() resp. receivedStderr() is emitted.
- You can shut down individual communication channels with closeStdin(), closeStdout(), and closeStderr(), resp.
Definition at line 127 of file k3process.h.
Member Enumeration Documentation
anonymous enum |
More or less intuitive constants for use with setPriority().
Enumerator | |
---|---|
PrioLowest | |
PrioLow | |
PrioLower | |
PrioNormal | |
PrioHigher | |
PrioHigh | |
PrioHighest |
Definition at line 530 of file k3process.h.
Modes in which the communication channels can be opened.
If communication for more than one channel is required, the values should be or'ed together, for example to get communication with stdout as well as with stdin, you would specify Stdin
| Stdout
Enumerator | |
---|---|
NoCommunication |
No communication with the process. |
Stdin |
Connect to write to the process with writeStdin(). |
Stdout |
Connect to read from the process' output. |
Stderr |
Connect to read from the process' stderr. |
AllOutput |
Connects to all output channels. |
All |
Connects to all channels. |
NoRead |
If specified with Stdout, no data is actually read from stdout, only the signal receivedStdout(int fd, int &len) is emitted. |
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. |
MergedStderr |
If specified with Stdout, the process' stderr will be redirected onto the same file handle as its stdout, i.e., all error output will be signalled with receivedStdout(). Don't specify Stderr if you specify MergedStderr. |
Definition at line 142 of file k3process.h.
enum K3Process::RunMode |
Run-modes for a child process.
Definition at line 165 of file k3process.h.
Constructor & Destructor Documentation
|
explicit |
Constructor.
Definition at line 103 of file k3process.cpp.
|
virtual |
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 DontCare
. Processes started as DontCare
keep running anyway.
Definition at line 181 of file k3process.cpp.
Member Function Documentation
|
inline |
Lets you see what your arguments are for debugging.
- Returns
- the list of arguments
Definition at line 435 of file k3process.h.
|
protected |
Called by slotChildError() this function copies data arriving from the child process' stderr to the respective buffer and emits the signal receivedStderr().
Definition at line 785 of file k3process.cpp.
|
protected |
Called by slotChildOutput() this function copies data arriving from the child process' stdout to the respective buffer and emits the signal receivedStdout().
Definition at line 762 of file k3process.cpp.
void K3Process::clearArguments | ( | ) |
Clear a command line argument list that has been set by using operator<<.
Definition at line 234 of file k3process.cpp.
void K3Process::closeAll | ( | ) |
Close stdin, stdout, stderr and the pty.
This is the same that calling all close* functions in a row:
- See also
- closeStdin,
- closeStdout,
- closeStderr and
- closePty
Definition at line 645 of file k3process.cpp.
bool K3Process::closePty | ( | ) |
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.
- Returns
- false if the pty is not open (any more).
Definition at line 634 of file k3process.cpp.
bool K3Process::closeStderr | ( | ) |
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.
- Returns
- false if no Stderr communication link exists (any more).
Definition at line 620 of file k3process.cpp.
bool K3Process::closeStdin | ( | ) |
Shuts down the Stdin communication link.
If no pty is used, this causes "EOF" to be indicated on the child's stdin file descriptor.
- Returns
- false if no Stdin communication link exists (any more).
Definition at line 592 of file k3process.cpp.
bool K3Process::closeStdout | ( | ) |
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.
- Returns
- false if no Stdout communication link exists (any more).
Definition at line 606 of file k3process.cpp.
|
protectedvirtual |
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.
- If pid() returns zero, the communication links should be closed only.
- if pid() returns non-zero and runs is false, all data immediately available from the communication links should be processed before closing them.
- if pid() returns non-zero and runs is true, the communication links should be monitored for data until the file handle returned by K3ProcessController::theKProcessController->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 K3Process (and thus the whole program) to lock up under certain circumstances. At the end the function closes the communication links in any case. Additionally
- 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.
- if runs is false, all data immediately available from the communication links is processed.
Definition at line 959 of file k3process.cpp.
|
protectedvirtual |
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.
Definition at line 911 of file k3process.cpp.
|
protectedvirtual |
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 QSocketNotifiers innot, outnot and errnot and connect their Qt signals to the respective K3Process slots.
For a more detailed explanation, it is best to have a look at the default implementation in kprocess.cpp.
Definition at line 866 of file k3process.cpp.
bool K3Process::coreDumped | ( | ) | const |
Checks whether a killed process dumped core.
- Returns
- 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.
Definition at line 538 of file k3process.cpp.
void K3Process::detach | ( | ) |
Detaches K3Process from child process.
All communication is closed. No exit notification is emitted any more for the child process. Deleting the K3Process will no longer kill the child process. Note that the current process remains the parent process of the child process.
Definition at line 194 of file k3process.cpp.
int K3Process::exitSignal | ( | ) | const |
Returns the signal the process was killed by.
- Returns
- the signal number that caused the process to exit. Note that this value is not valid if signalled() returns false.
Definition at line 554 of file k3process.cpp.
int K3Process::exitStatus | ( | ) | const |
Returns the exit status of the process.
- Returns
- the exit status of the process. Note that this value is not valid if normalExit() returns false.
Definition at line 548 of file k3process.cpp.
bool K3Process::isRunning | ( | ) | const |
Checks whether the process is running.
- Returns
- true if the process is (still) considered to be running
Definition at line 438 of file k3process.cpp.
|
virtual |
Stop the process (by sending it a signal).
- Parameters
-
signo The signal to send. The default is SIGTERM.
- Returns
- true if the signal was delivered successfully.
Definition at line 429 of file k3process.cpp.
bool K3Process::normalExit | ( | ) | const |
Checks whether the process exited cleanly.
- Returns
- true if the process has already finished and has exited "voluntarily", ie: it has not been killed by a signal.
Definition at line 526 of file k3process.cpp.
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:
- Parameters
-
arg the argument to add
- Returns
- a reference to this K3Process
Definition at line 228 of file k3process.cpp.
K3Process & K3Process::operator<< | ( | const char * | arg | ) |
Similar to previous method, takes a char *, supposed to be in locale 8 bit already.
Definition at line 222 of file k3process.cpp.
K3Process & K3Process::operator<< | ( | const QByteArray & | arg | ) |
Similar to previous method, takes a QByteArray, supposed to be in locale 8 bit already.
- Parameters
-
arg the argument to add
- Returns
- a reference to this K3Process
Definition at line 217 of file k3process.cpp.
K3Process & K3Process::operator<< | ( | const QStringList & | args | ) |
Sets the executable and the command line argument list for this process, in a single method call, or add a list of arguments.
- Parameters
-
args the arguments to add
- Returns
- a reference to this K3Process
Definition at line 209 of file k3process.cpp.
pid_t K3Process::pid | ( | ) | 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 K3Process.
Calling it before any child process has been started by this K3Process instance causes pid() to return 0.
- Returns
- the pid of the process or 0 if no process has been started yet.
Definition at line 445 of file k3process.cpp.
|
signal |
Emitted after the process has terminated when the process was run in the NotifyOnExit
(==default option to start() ) or the Block mode.
- Parameters
-
proc a pointer to the process that has exited
|
protectedvirtual |
Immediately called after a successfully started process in NotifyOnExit mode has exited.
This function normally calls commClose() and emits the processExited() signal.
- Parameters
-
state the exit code of the process as returned by waitpid()
Definition at line 747 of file k3process.cpp.
KPty * K3Process::pty | ( | ) | const |
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.
- Returns
- a pointer to the pty object
Definition at line 730 of file k3process.cpp.
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.
- Parameters
-
arg the argument to quote
- Returns
- the quoted argument
Definition at line 735 of file k3process.cpp.
|
signal |
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 buffer
to your private data structures before returning from the slot.
- Parameters
-
proc a pointer to the process that has received the data buffer The data received. buflen The number of bytes that are available.
|
signal |
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().
- Parameters
-
proc a pointer to the process that has received the output buffer The data received. buflen The number of bytes that are available.
You should copy the information contained in buffer
to your private data structures before returning from the slot. Example:
|
signal |
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 fd
.
- Parameters
-
fd the file descriptor that provides the data len the number of bytes that have been read from fd
must be written here
void K3Process::resume | ( | ) |
Resume processing of data from stdout of the child process.
Definition at line 586 of file k3process.cpp.
bool K3Process::runPrivileged | ( | ) | const |
Returns whether the started process will drop any setuid/setgid privileges or whether it will keep them.
- Returns
- true if the process runs privileged
Definition at line 162 of file k3process.cpp.
|
protected |
Specify the actual executable that should be started (first argument to execve) Normally the first argument is the executable but you can override that with this function.
Definition at line 204 of file k3process.cpp.
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
Definition at line 129 of file k3process.cpp.
bool K3Process::setPriority | ( | int | prio | ) |
Sets the scheduling priority of the process.
- Parameters
-
prio the new priority in the range -20 (high) to 19 (low).
- Returns
- false on error; see setpriority(2) for possible reasons.
Definition at line 168 of file k3process.cpp.
void K3Process::setRunPrivileged | ( | bool | keepPrivileges | ) |
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
- Parameters
-
keepPrivileges true to keep the privileges
Definition at line 156 of file k3process.cpp.
|
protectedvirtual |
This function is called from start() right before a fork() takes place.
According to the comm
parameter this function has to initialize the in, out and err data members of K3Process.
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.
Definition at line 800 of file k3process.cpp.
|
protected |
Sets up the environment according to the data passed via setEnvironment()
Definition at line 141 of file k3process.cpp.
void K3Process::setUsePty | ( | Communication | comm, |
bool | addUtmp | ||
) |
Specify whether to create a pty (pseudo-terminal) for running the command.
This function should be called before starting the process.
- Parameters
-
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). addUtmp true if a utmp entry should be created for the pty
Definition at line 717 of file k3process.cpp.
void K3Process::setUseShell | ( | bool | useShell, |
const char * | shell = 0 |
||
) |
Specify whether to start the command via a shell or directly.
The default is to start the command directly. If useShell
is true 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 also
- quote()
- Parameters
-
useShell true if the command should be started via a shell 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.
Definition at line 693 of file k3process.cpp.
void K3Process::setWorkingDirectory | ( | const QString & | dir | ) |
Changes the current working directory (CWD) of the process to be started.
This function must be called before starting the process.
- Parameters
-
dir the new directory
Definition at line 135 of file k3process.cpp.
bool K3Process::signalled | ( | ) | const |
Checks whether the process was killed by a signal.
- Returns
- true if the process has already finished and has not exited "voluntarily", ie: it has been killed by a signal.
Definition at line 532 of file k3process.cpp.
|
protectedslot |
This slot gets activated when data from the child's stderr arrives.
It usually calls childError().
- Parameters
-
fdno the file descriptor for the output
Definition at line 666 of file k3process.cpp.
|
protectedslot |
This slot gets activated when data from the child's stdout arrives.
It usually calls childOutput().
- Parameters
-
fdno the file descriptor for the output
Definition at line 659 of file k3process.cpp.
|
protectedslot |
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.
- Parameters
-
dummy ignore this argument
Definition at line 673 of file k3process.cpp.
|
virtual |
Starts the process.
For a detailed description of the various run modes and communication semantics, have a look at the general description of the K3Process 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:
- The process is already running.
- The command line argument list is empty.
- The the
comm
parameter is incompatible with the selected pty usage. - The starting of the process failed (could not fork).
- The executable was not found.
- Parameters
-
runmode The Run-mode for the process. comm Specifies which communication channels 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.
- Returns
- true on success, false on error (see above for error conditions)
Reimplemented in K3ShellProcess.
Definition at line 239 of file k3process.cpp.
void K3Process::suspend | ( | ) |
Suspend processing of data from stdout of the child process.
Definition at line 580 of file k3process.cpp.
bool K3Process::wait | ( | int | timeout = -1 | ) |
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.
- Parameters
-
timeout timeout in seconds. -1 means wait indefinitely.
- Returns
- true if the process exited, false if the timeout hit.
Definition at line 462 of file k3process.cpp.
bool K3Process::writeStdin | ( | const char * | buffer, |
int | buflen | ||
) |
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 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.
- Parameters
-
buffer the buffer to write buflen the length of the buffer
- Returns
- false if an error has occurred
Definition at line 560 of file k3process.cpp.
|
signal |
Emitted after all the data that has been specified by a prior call to writeStdin() has actually been written to the child process.
- Parameters
-
proc a pointer to the process
Member Data Documentation
|
protected |
The list of the process' command line arguments.
The first entry in this list is the executable itself.
Definition at line 652 of file k3process.h.
|
protected |
Lists the communication links that are activated for the child process.
Should not be modified from derived classes.
Definition at line 808 of file k3process.h.
|
protected |
The socket descriptors for stderr.
Definition at line 789 of file k3process.h.
|
protected |
The socket notifier for err[0].
Definition at line 802 of file k3process.h.
|
protected |
The socket descriptors for stdin.
Definition at line 785 of file k3process.h.
|
protected |
The socket notifier for in[1].
Definition at line 794 of file k3process.h.
|
protected |
The buffer holding the data that has to be sent to the child.
Definition at line 827 of file k3process.h.
|
protected |
The number of bytes already transmitted.
Definition at line 831 of file k3process.h.
|
protected |
The total length of input_data.
Definition at line 835 of file k3process.h.
|
protected |
If false, the child process' effective uid & gid will be reset to the real values.
- See also
- setRunPrivileged()
Definition at line 690 of file k3process.h.
|
protected |
The socket descriptors for stdout.
Definition at line 781 of file k3process.h.
|
protected |
The socket notifier for out[0].
Definition at line 798 of file k3process.h.
|
protected |
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 K3Process.
Definition at line 673 of file k3process.h.
|
protected |
How to run the process (Block, NotifyOnExit, DontCare).
You should not modify this data member directly from derived classes.
Definition at line 657 of file k3process.h.
|
protected |
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 K3Process.
Definition at line 664 of file k3process.h.
|
protected |
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 K3Process.
Definition at line 682 of file k3process.h.
The documentation for this class was generated from the following files:
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