change configure to better detect gstreamer. Check create is valid in mediaplayer...

[wxWidgets.git] / docs / latex / wx / process.tex

diff --git a/docs/latex/wx/process.tex b/docs/latex/wx/process.tex
index 6d4ba8232ce49317452bc0195c1b94ccf5a26340..4f94f2b2a67343113ae5f71d2bb4d91c042b52c8 100644 (file)
--- a/docs/latex/wx/process.tex
+++ b/docs/latex/wx/process.tex
@@ -1,6 +1,6 @@
 \section{\class{wxProcess}}\label{wxprocess}
 
 \section{\class{wxProcess}}\label{wxprocess}
 

-The objects of this class are used in conjonction with 
+The objects of this class are used in conjunction with the

 \helpref{wxExecute}{wxexecute} function. When a wxProcess object is passed to
 wxExecute(), its \helpref{OnTerminate()}{wxprocessonterminate} virtual method
 is called when the process terminates. This allows the program to be
 \helpref{wxExecute}{wxexecute} function. When a wxProcess object is passed to
 wxExecute(), its \helpref{OnTerminate()}{wxprocessonterminate} virtual method
 is called when the process terminates. This allows the program to be


@@ -14,6 +14,18 @@ However, if it is not processed, the object will delete itself and so the
 library users should only delete those objects whose notifications have been
 processed (and call \helpref{Detach()}{wxprocessdetach} for others).
 
 library users should only delete those objects whose notifications have been
 processed (and call \helpref{Detach()}{wxprocessdetach} for others).
 

+wxProcess also supports IO redirection of the child process. For this, you have
+to call its \helpref{Redirect}{wxprocessredirect} method before passing it to
+\helpref{wxExecute}{wxexecute}. If the child process was launched successfully,
+\helpref{GetInputStream}{wxprocessgetinputstream},
+\helpref{GetOutputStream}{wxprocessgetoutputstream} and
+\helpref{GetErrorStream}{wxprocessgeterrorstream} can then be used to retrieve
+the streams corresponding to the child process standard output, input and
+error output respectively.
+
+\perlnote{In wxPerl this class has an additional {\tt Destroy} method,
+for explicit destruction.}
+

 \wxheading{Derived from}
 
 \helpref{wxEvtHandler}{wxevthandler}
 \wxheading{Derived from}
 
 \helpref{wxEvtHandler}{wxevthandler}


@@ -22,32 +34,56 @@ processed (and call \helpref{Detach()}{wxprocessdetach} for others).
 
 <wx/process.h>
 
 
 <wx/process.h>
 

+\wxheading{See also}
+
+\helpref{wxExecute}{wxexecute}\\
+\helpref{exec sample}{sampleexec}
+

 \latexignore{\rtfignore{\wxheading{Members}}}
 
 \latexignore{\rtfignore{\wxheading{Members}}}
 

-\membersection{wxProcess::wxProcess}\label{wxprocessconstr}
+\membersection{wxProcess::wxProcess}\label{wxprocessctor}

 
 \func{}{wxProcess}{\param{wxEvtHandler *}{ parent = NULL}, \param{int}{ id = -1}}
 
 
 \func{}{wxProcess}{\param{wxEvtHandler *}{ parent = NULL}, \param{int}{ id = -1}}
 

+\func{}{wxProcess}{\param{int }{flags}}
+

 Constructs a process object. {\it id} is only used in the case you want to
 Constructs a process object. {\it id} is only used in the case you want to

-use wxWindows events. It identifies this object, or another window that will
+use wxWidgets events. It identifies this object, or another window that will

 receive the event.
 
 If the {\it parent} parameter is different from NULL, it will receive
 a wxEVT\_END\_PROCESS notification event (you should insert EVT\_END\_PROCESS
 macro in the event table of the parent to handle it) with the given {\it id}.
 
 receive the event.
 
 If the {\it parent} parameter is different from NULL, it will receive
 a wxEVT\_END\_PROCESS notification event (you should insert EVT\_END\_PROCESS
 macro in the event table of the parent to handle it) with the given {\it id}.
 

+The second constructor creates an object without any associated parent (and
+hence no id neither) but allows to specify the {\it flags} which can have the
+value of {\tt wxPROCESS\_DEFAULT} or {\tt wxPROCESS\_REDIRECT}. Specifying the
+former value has no particular effect while using the latter one is equivalent
+to calling \helpref{Redirect}{wxprocessredirect}.
+

 \wxheading{Parameters}
 
 \docparam{parent}{The event handler parent.}
 
 \docparam{id}{id of an event.}
 
 \wxheading{Parameters}
 
 \docparam{parent}{The event handler parent.}
 
 \docparam{id}{id of an event.}
 

-\membersection{wxProcess::\destruct{wxProcess}}
+\docparam{flags}{either {\tt wxPROCESS\_DEFAULT} or {\tt wxPROCESS\_REDIRECT}}
+
+\membersection{wxProcess::\destruct{wxProcess}}\label{wxprocessdtor}

 
 \func{}{\destruct{wxProcess}}{\void}
 
 Destroys the wxProcess object.
 
 
 \func{}{\destruct{wxProcess}}{\void}
 
 Destroys the wxProcess object.
 

+\membersection{wxProcess::CloseOutput}\label{wxprocesscloseoutput}
+
+\func{void}{CloseOutput}{\void}
+
+Closes the output stream (the one connected to the stdin of the child
+process). This function can be used to indicate to the child process that
+there is no more data to be read - usually, a filter program will only
+terminate when the input stream is closed.
+

 \membersection{wxProcess::Detach}\label{wxprocessdetach}
 
 \func{void}{Detach}{\void}
 \membersection{wxProcess::Detach}\label{wxprocessdetach}
 
 \func{void}{Detach}{\void}


@@ -56,20 +92,180 @@ Normally, a wxProcess object is deleted by its parent when it receives the
 notification about the process termination. However, it might happen that the
 parent object is destroyed before the external process is terminated (e.g. a
 window from which this external process was launched is closed by the user)
 notification about the process termination. However, it might happen that the
 parent object is destroyed before the external process is terminated (e.g. a
 window from which this external process was launched is closed by the user)

-and in this case it {\bf should not delete} the wxProcess object, but 
+and in this case it {\bf should not delete} the wxProcess object, but

 {\bf should call Detach()} instead. After the wxProcess object is detached
 from its parent, no notification events will be sent to the parent and the
 object will delete itself upon reception of the process termination
 notification.
 
 {\bf should call Detach()} instead. After the wxProcess object is detached
 from its parent, no notification events will be sent to the parent and the
 object will delete itself upon reception of the process termination
 notification.
 

+\membersection{wxProcess::GetErrorStream}\label{wxprocessgeterrorstream}
+
+\constfunc{wxInputStream* }{GetErrorStream}{\void}
+
+Returns an input stream which corresponds to the standard error output (stderr)
+of the child process.
+
+\membersection{wxProcess::GetInputStream}\label{wxprocessgetinputstream}
+
+\constfunc{wxInputStream* }{GetInputStream}{\void}
+
+It returns an input stream corresponding to the standard output stream of the
+subprocess. If it is NULL, you have not turned on the redirection.
+See \helpref{wxProcess::Redirect}{wxprocessredirect}.
+
+\membersection{wxProcess::GetOutputStream}\label{wxprocessgetoutputstream}
+
+\constfunc{wxOutputStream* }{GetOutputStream}{\void}
+
+It returns an output stream correspoding to the input stream of the subprocess.
+If it is NULL, you have not turned on the redirection.
+See \helpref{wxProcess::Redirect}{wxprocessredirect}.
+
+\membersection{wxProcess::IsErrorAvailable}\label{wxprocessiserroravailable}
+
+\constfunc{bool}{IsErrorAvailable}{\void}
+
+Returns {\tt true} if there is data to be read on the child process standard
+error stream.
+
+\wxheading{See also}
+
+\helpref{IsInputAvailable}{wxprocessisinputavailable}
+
+\membersection{wxProcess::IsInputAvailable}\label{wxprocessisinputavailable}
+
+\constfunc{bool}{IsInputAvailable}{\void}
+
+Returns {\tt true} if there is data to be read on the child process standard
+output stream. This allows to write simple (and extremely inefficient)
+polling-based code waiting for a better mechanism in future wxWidgets versions.
+
+See the \helpref{exec sample}{sampleexec} for an example of using this
+function.
+
+\wxheading{See also}
+
+\helpref{IsInputOpened}{wxprocessisinputopened}
+
+\membersection{wxProcess::IsInputOpened}\label{wxprocessisinputopened}
+
+\constfunc{bool}{IsInputOpened}{\void}
+
+Returns {\tt true} if the child process standard output stream is opened.
+
+\membersection{wxProcess::Kill}\label{wxprocesskill}
+
+\func{static wxKillError}{Kill}{\param{int}{ pid}, \param{wxSignal}{ signal = wxSIGNONE}, \param{int }{flags = wxKILL\_NOCHILDREN}}
+
+Send the specified signal to the given process. Possible signal values are:
+
+\begin{verbatim}
+enum wxSignal
+{
+    wxSIGNONE = 0,  // verify if the process exists under Unix
+    wxSIGHUP,
+    wxSIGINT,
+    wxSIGQUIT,
+    wxSIGILL,
+    wxSIGTRAP,
+    wxSIGABRT,
+    wxSIGEMT,
+    wxSIGFPE,
+    wxSIGKILL,      // forcefully kill, dangerous!
+    wxSIGBUS,
+    wxSIGSEGV,
+    wxSIGSYS,
+    wxSIGPIPE,
+    wxSIGALRM,
+    wxSIGTERM       // terminate the process gently
+};
+\end{verbatim}
+
+{\tt wxSIGNONE}, {\tt wxSIGKILL} and {\tt wxSIGTERM} have the same meaning
+under both Unix and Windows but all the other signals are equivalent to
+{\tt wxSIGTERM} under Windows.
+
+The {\it flags} parameter can be wxKILL\_NOCHILDREN (the default),
+or wxKILL\_CHILDREN, in which case the child processes of this
+process will be killed too. Note that under Unix, for wxKILL\_CHILDREN
+to work you should have created the process passing wxEXEC\_MAKE\_GROUP\_LEADER.
+
+Returns the element of {\tt wxKillError} enum:
+
+\begin{verbatim}
+enum wxKillError
+{
+    wxKILL_OK,              // no error
+    wxKILL_BAD_SIGNAL,      // no such signal
+    wxKILL_ACCESS_DENIED,   // permission denied
+    wxKILL_NO_PROCESS,      // no such process
+    wxKILL_ERROR            // another, unspecified error
+};
+\end{verbatim}
+
+\wxheading{See also}
+
+\helpref{wxProcess::Exists}{wxprocessexists},\rtfsp
+\helpref{wxKill}{wxkill},\rtfsp
+\helpref{Exec sample}{sampleexec}
+
+\membersection{wxProcess::Exists}\label{wxprocessexists}
+
+\func{static bool}{Exists}{\param{int}{ pid}}
+
+Returns {\tt true} if the given process exists in the system.
+
+\wxheading{See also}
+
+\helpref{wxProcess::Kill}{wxprocesskill},\rtfsp
+\helpref{Exec sample}{sampleexec}
+

 \membersection{wxProcess::OnTerminate}\label{wxprocessonterminate}
 
 \membersection{wxProcess::OnTerminate}\label{wxprocessonterminate}
 

-\constfunc{void}{OnTerminate}{\param{int}{ pid}, \param{int}{ status}}
+\func{void}{OnTerminate}{\param{int}{ pid}, \param{int}{ status}}

 
 It is called when the process with the pid {\it pid} finishes.
 
 It is called when the process with the pid {\it pid} finishes.

-It raises a wxWindows event when it isn't overriden.
+It raises a wxWidgets event when it isn't overridden.

 
 \docparam{pid}{The pid of the process which has just terminated.}
 
 \docparam{status}{The exit code of the process.}
 
 
 \docparam{pid}{The pid of the process which has just terminated.}
 
 \docparam{status}{The exit code of the process.}
 

+\membersection{wxProcess::Open}\label{wxprocessopen}
+
+\func{static wxProcess *}{Open}{\param{const wxString\& }{cmd}, \param{int }{flags = wxEXEC\_ASYNC}}
+
+This static method replaces the standard {\tt popen()} function: it launches
+the process specified by the {\it cmd} parameter and returns the wxProcess
+object which can be used to retrieve the streams connected to the standard
+input, output and error output of the child process.
+
+If the process couldn't be launched, {\tt NULL} is returned. Note that in any
+case the returned pointer should {\bf not} be deleted, rather the process
+object will be destroyed automatically when the child process terminates. This
+does mean that the child process should be told to quit before the main program
+exits to avoid memory leaks.
+
+\wxheading{Parameters}
+
+\docparam{cmd}{The command to execute, including optional arguments.}
+\docparam{flags}{The flags to pass to \helpref{wxExecute}{wxexecute}.
+  NOTE: wxEXEC\_SYNC should not be used.}
+
+\wxheading{Return value}
+
+A pointer to new wxProcess object or {\tt NULL} on error.
+
+\wxheading{See also}
+
+\helpref{wxExecute}{wxexecute}
+
+\membersection{wxProcess::Redirect}\label{wxprocessredirect}
+
+\func{void}{Redirect}{\void}
+
+Turns on redirection. wxExecute will try to open a couple of pipes
+to catch the subprocess stdio. The caught input stream is returned by
+GetOutputStream() as a non-seekable stream. The caught output stream is returned
+by GetInputStream() as a non-seekable stream.
+