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1 | \section{\class{wxProcess}}\label{wxprocess} | |
2 | ||
3 | The objects of this class are used in conjunction with | |
4 | \helpref{wxExecute}{wxexecute} function. When a wxProcess object is passed to | |
5 | wxExecute(), its \helpref{OnTerminate()}{wxprocessonterminate} virtual method | |
6 | is called when the process terminates. This allows the program to be | |
7 | (asynchronously) notified about the process termination and also retrieve its | |
8 | exit status which is unavailable from wxExecute() in the case of | |
9 | asynchronous execution. | |
10 | ||
11 | Please note that if the process termination notification is processed by the | |
12 | parent, it is responsible for deleting the wxProcess object which sent it. | |
13 | However, if it is not processed, the object will delete itself and so the | |
14 | library users should only delete those objects whose notifications have been | |
15 | processed (and call \helpref{Detach()}{wxprocessdetach} for others). | |
16 | ||
17 | wxProcess also supports IO redirection of the child process. For this, you have | |
18 | to call its \helpref{Redirect}{wxprocessredirect} method before passing it to | |
19 | \helpref{wxExecute}{wxexecute}. If the child process was launched successfully, | |
20 | \helpref{GetInputStream}{wxprocessgetinputstream}, | |
21 | \helpref{GetOutputStream}{wxprocessgetoutputstream} and | |
22 | \helpref{GetErrorStream}{wxprocessgeterrorstream} can then be used to retrieve | |
23 | the streams corresponding to the child process stdandard output, input and | |
24 | error output respectively. | |
25 | ||
26 | \wxheading{Derived from} | |
27 | ||
28 | \helpref{wxEvtHandler}{wxevthandler} | |
29 | ||
30 | \wxheading{Include files} | |
31 | ||
32 | <wx/process.h> | |
33 | ||
34 | \wxheading{See also} | |
35 | ||
36 | \helpref{wxExecute}{wxexecute}\\ | |
37 | \helpref{exec sample}{sampleexec} | |
38 | ||
39 | \latexignore{\rtfignore{\wxheading{Members}}} | |
40 | ||
41 | \membersection{wxProcess::wxProcess}\label{wxprocessconstr} | |
42 | ||
43 | \func{}{wxProcess}{\param{wxEvtHandler *}{ parent = NULL}, \param{int}{ id = -1}} | |
44 | ||
45 | Constructs a process object. {\it id} is only used in the case you want to | |
46 | use wxWindows events. It identifies this object, or another window that will | |
47 | receive the event. | |
48 | ||
49 | If the {\it parent} parameter is different from NULL, it will receive | |
50 | a wxEVT\_END\_PROCESS notification event (you should insert EVT\_END\_PROCESS | |
51 | macro in the event table of the parent to handle it) with the given {\it id}. | |
52 | ||
53 | \wxheading{Parameters} | |
54 | ||
55 | \docparam{parent}{The event handler parent.} | |
56 | ||
57 | \docparam{id}{id of an event.} | |
58 | ||
59 | \membersection{wxProcess::\destruct{wxProcess}} | |
60 | ||
61 | \func{}{\destruct{wxProcess}}{\void} | |
62 | ||
63 | Destroys the wxProcess object. | |
64 | ||
65 | \membersection{wxProcess::CloseOutput}\label{wxprocesscloseoutput} | |
66 | ||
67 | \func{void}{CloseOutput}{\void} | |
68 | ||
69 | Closes the output stream (the one connected to the stdin of the child | |
70 | process). This function can be used to indicate to the child process that | |
71 | there is no more data to be read - usually, a filter program will only | |
72 | terminate when the input stream is closed. | |
73 | ||
74 | \membersection{wxProcess::Detach}\label{wxprocessdetach} | |
75 | ||
76 | \func{void}{Detach}{\void} | |
77 | ||
78 | Normally, a wxProcess object is deleted by its parent when it receives the | |
79 | notification about the process termination. However, it might happen that the | |
80 | parent object is destroyed before the external process is terminated (e.g. a | |
81 | window from which this external process was launched is closed by the user) | |
82 | and in this case it {\bf should not delete} the wxProcess object, but | |
83 | {\bf should call Detach()} instead. After the wxProcess object is detached | |
84 | from its parent, no notification events will be sent to the parent and the | |
85 | object will delete itself upon reception of the process termination | |
86 | notification. | |
87 | ||
88 | \membersection{wxProcess::GetErrorStream}\label{wxprocessgeterrorstream} | |
89 | ||
90 | \constfunc{wxInputStream* }{GetErrorStream}{\void} | |
91 | ||
92 | Returns an input stream which corresponds to the standard error output (stderr) | |
93 | of the child process. | |
94 | ||
95 | \membersection{wxProcess::GetInputStream}\label{wxprocessgetinputstream} | |
96 | ||
97 | \constfunc{wxInputStream* }{GetInputStream}{\void} | |
98 | ||
99 | It returns a output stream corresponding to the standard output stream of the | |
100 | subprocess. If it is NULL, you have not turned on the redirection. | |
101 | See \helpref{wxProcess::Redirect}{wxprocessredirect}. | |
102 | ||
103 | \membersection{wxProcess::GetOutputStream}\label{wxprocessgetoutputstream} | |
104 | ||
105 | \constfunc{wxOutputStream* }{GetOutputStream}{\void} | |
106 | ||
107 | It returns an output stream correspoding to the input stream of the subprocess. | |
108 | If it is NULL, you have not turned on the redirection. | |
109 | See \helpref{wxProcess::Redirect}{wxprocessredirect}. | |
110 | ||
111 | \membersection{wxProcess::OnTerminate}\label{wxprocessonterminate} | |
112 | ||
113 | \constfunc{void}{OnTerminate}{\param{int}{ pid}, \param{int}{ status}} | |
114 | ||
115 | It is called when the process with the pid {\it pid} finishes. | |
116 | It raises a wxWindows event when it isn't overridden. | |
117 | ||
118 | \docparam{pid}{The pid of the process which has just terminated.} | |
119 | ||
120 | \docparam{status}{The exit code of the process.} | |
121 | ||
122 | \membersection{wxProcess::Redirect}\label{wxprocessredirect} | |
123 | ||
124 | \func{void}{Redirect}{\void} | |
125 | ||
126 | It turns on the redirection, wxExecute will try to open a couple of pipes | |
127 | to catch the subprocess stdio. The caught input stream is returned by | |
128 | GetOutputStream() as a non-seekable stream. The caught output stream is returned | |
129 | by GetInputStream() as a non-seekable stream. | |
130 |