From 7e84f02dfda7d5e3cf2cef1aa85169c55e8d4461 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Wed, 17 Feb 1999 17:56:59 +0000
Subject: [PATCH] wxProcess fixes (Detach() added), cleared/corrected
 wxExecute() documentation

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@1709 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 docs/latex/wx/function.tex |  9 ++--
 docs/latex/wx/process.tex  | 40 ++++++++++++++---
 include/wx/process.h       |  8 +++-
 src/common/process.cpp     | 22 ++++++---
 src/gtk/utilsgtk.cpp       | 91 ++++++++++++++++++++------------------
 src/gtk1/utilsgtk.cpp      | 91 ++++++++++++++++++++------------------
 6 files changed, 155 insertions(+), 106 deletions(-)

diff --git a/docs/latex/wx/function.tex b/docs/latex/wx/function.tex
index 655af485a7..d4888be1db 100644
--- a/docs/latex/wx/function.tex
+++ b/docs/latex/wx/function.tex
@@ -946,11 +946,12 @@ arguments, terminated by NULL.
 If {\it sync} is FALSE (the default), flow of control immediately returns.
 If TRUE, the current application waits until the other program has terminated.
 
-If execution is asynchronous, the return value is the process id,
-otherwise it is a status value.  A zero value indicates that the command could not
-be executed.
+The return value is the process id, not the exit code of invoked program (for
+this you should use wxProcess). A zero value indicates that the command could
+not be executed.
 
-If callback isn't NULL and if execution is asynchronous, 
+If callback isn't NULL and if execution is asynchronous (note that callback
+parameter can not be non NULL for synchronous execution), 
 \helpref{wxProcess::OnTerminate}{wxprocessonterminate} will be called when
 the process finishes.
 
diff --git a/docs/latex/wx/process.tex b/docs/latex/wx/process.tex
index b09bb386ef..6d4ba8232c 100644
--- a/docs/latex/wx/process.tex
+++ b/docs/latex/wx/process.tex
@@ -1,8 +1,18 @@
 \section{\class{wxProcess}}\label{wxprocess}
 
-This class contains a method which is invoked when a process finishes.
-It can raise a \helpref{wxProcessEvent}{wxprocessevent} if wxProcess::OnTerminate
-isn't overriden.
+The objects of this class are used in conjonction with 
+\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
+(asynchronously) notified about the process termination and also retrieve its
+exit status which is unavailable from wxExecute() in the case of
+asynchronous execution.
+
+Please note that if the process termination notification is processed by the
+parent, it is responsible for deleting the wxProcess object which sent it.
+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).
 
 \wxheading{Derived from}
 
@@ -22,6 +32,10 @@ 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
 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}.
+
 \wxheading{Parameters}
 
 \docparam{parent}{The event handler parent.}
@@ -34,12 +48,28 @@ receive the event.
 
 Destroys the wxProcess object.
 
+\membersection{wxProcess::Detach}\label{wxprocessdetach}
+
+\func{void}{Detach}{\void}
+
+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)
+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.
+
 \membersection{wxProcess::OnTerminate}\label{wxprocessonterminate}
 
-\constfunc{void}{OnTerminate}{\param{int}{ pid}}
+\constfunc{void}{OnTerminate}{\param{int}{ pid}, \param{int}{ status}}
 
 It is called when the process with the pid {\it pid} finishes.
 It raises a wxWindows event when it isn't overriden.
 
-\docparam{pid}{The pid of the process which ends.}
+\docparam{pid}{The pid of the process which has just terminated.}
+
+\docparam{status}{The exit code of the process.}
 
diff --git a/include/wx/process.h b/include/wx/process.h
index dc4d5a43a9..b612306a66 100644
--- a/include/wx/process.h
+++ b/include/wx/process.h
@@ -2,11 +2,11 @@
 // Name:        process.h
 // Purpose:     wxProcess class
 // Author:      Guilhem Lavaux
-// Modified by:
+// Modified by: Vadim Zeitlin to check error codes, added Detach() method
 // Created:     24/06/98
 // RCS-ID:      $Id$
 // Copyright:   (c) 1998 Guilhem Lavaux
-// Licence:   	wxWindows license
+// Licence:     wxWindows license
 /////////////////////////////////////////////////////////////////////////////
 
 #ifndef _WX_PROCESSH__
@@ -55,6 +55,10 @@ public:
 
     virtual void OnTerminate(int pid, int status);
 
+    // detach from the parent - should be called by the parent if it's deleted
+    // before the process it started terminates
+    void Detach();
+
 protected:
     int m_id;
 };
diff --git a/src/common/process.cpp b/src/common/process.cpp
index 2469953ed2..6440993d20 100644
--- a/src/common/process.cpp
+++ b/src/common/process.cpp
@@ -2,11 +2,11 @@
 // Name:        process.cpp
 // Purpose:     Process termination classes
 // Author:      Guilhem Lavaux
-// Modified by:
+// Modified by: Vadim Zeitlin to check error codes, added Detach() method
 // Created:     24/06/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux
-// Licence:   	wxWindows license
+// Licence:     wxWindows license
 /////////////////////////////////////////////////////////////////////////////
 
 #ifdef __GNUG__
@@ -31,15 +31,23 @@ IMPLEMENT_DYNAMIC_CLASS(wxProcessEvent, wxEvent)
 
 wxProcess::wxProcess(wxEvtHandler *parent, int id)
 {
-  if (parent)
-    SetNextHandler(parent);
+    if (parent)
+        SetNextHandler(parent);
 
-  m_id = id;
+    m_id = id;
 }
 
 void wxProcess::OnTerminate(int pid, int status)
 {
-  wxProcessEvent event(m_id, pid, status);
+    wxProcessEvent event(m_id, pid, status);
 
-  ProcessEvent(event);
+    if ( !ProcessEvent(event) )
+        delete this;
+    //else: the object which processed the event is responsible for deleting
+    //      us!
+}
+
+void wxProcess::Detach()
+{
+    SetNextHandler(NULL);
 }
diff --git a/src/gtk/utilsgtk.cpp b/src/gtk/utilsgtk.cpp
index ba3988e154..fd92f99ba4 100644
--- a/src/gtk/utilsgtk.cpp
+++ b/src/gtk/utilsgtk.cpp
@@ -96,7 +96,7 @@ int wxGetOsVersion(int *majorVsn, int *minorVsn)
 {
   if (majorVsn) *majorVsn = GTK_MAJOR_VERSION;
   if (minorVsn) *minorVsn = GTK_MINOR_VERSION;
-  
+
   return wxGTK;
 }
 
@@ -123,11 +123,11 @@ char *wxGetUserHome( const wxString &user )
 	{
             return ptr;
 	}
-        if ((ptr = getenv("USER")) != NULL || (ptr = getenv("LOGNAME")) != NULL) 
+        if ((ptr = getenv("USER")) != NULL || (ptr = getenv("LOGNAME")) != NULL)
 	{
             who = getpwnam(ptr);
         }
-	
+
         /* We now make sure the the user exists! */
         if (who == NULL)
 	{
@@ -299,10 +299,10 @@ long wxExecute( char **argv, bool sync, wxProcess *process )
     wxCHECK_MSG( *argv, 0, "can't exec empty command" );
 
     /* Create pipes */
-    if (pipe(end_proc_detect) == -1) 
+    if (pipe(end_proc_detect) == -1)
     {
-      wxLogSysError( "Pipe creation failed" );
-      return 0;
+        wxLogSysError( "Pipe creation failed" );
+        return 0;
     }
 
     /* fork the process */
@@ -311,65 +311,68 @@ long wxExecute( char **argv, bool sync, wxProcess *process )
 #else
     pid_t pid = fork();
 #endif
-    if (pid == -1) 
+    if (pid == -1)
     {
         wxLogSysError( "Fork failed" );
         return 0;
     }
-    else if (pid == 0) 
+    else if (pid == 0)
     {
         // we're in child
         close(end_proc_detect[0]); // close reading side
-	// These three lines close the open file descriptors to
-	// to avoid any input/output which might block the process
-	// or irritate the user. If one wants proper IO for the sub-
-	// process, the "right thing to do" is to start an xterm executing
-	// it.
-	close(STDIN_FILENO);
-	close(STDOUT_FILENO);
-	close(STDERR_FILENO);
+
+        // These three lines close the open file descriptors to
+        // to avoid any input/output which might block the process
+        // or irritate the user. If one wants proper IO for the sub-
+        // process, the "right thing to do" is to start an xterm executing
+        // it.
+        close(STDIN_FILENO);
+        close(STDOUT_FILENO);
+        close(STDERR_FILENO);
+
         // some programs complain about sterr not being open, so
         // redirect them:
         open("/dev/null", O_RDONLY);  // stdin
-	open("/dev/null", O_WRONLY);  // stdout
-	open("/dev/null", O_WRONLY);  // stderr
-        
+        open("/dev/null", O_WRONLY);  // stdout
+        open("/dev/null", O_WRONLY);  // stderr
+
 
 #ifdef _AIX
         execvp ((const char *)*argv, (const char **)argv);
 #else
         execvp (*argv, argv);
 #endif
+
         // there is no return after successful exec()
         wxLogSysError( "Can't execute '%s'", *argv);
 
         _exit(-1);
     }
-    else 
+    else
     {
-      // we're in parent
-      close(end_proc_detect[1]); // close writing side
-      data->tag = gdk_input_add(end_proc_detect[0], GDK_INPUT_READ,
-                                GTK_EndProcessDetector, (gpointer)data);
-      data->pid = pid;
-      if (!sync) 
-      {
-        data->process = process;
-      }
-      else 
-      {
-        data->process = (wxProcess *) NULL;
-        data->pid = -(data->pid);
-
-        while (data->pid != 0)
-          wxYield();
-
-        delete data;
-      }
-
-      // @@@ our return value indicates success even if execvp() in the child
-      //     failed!
-      return pid;
+        // we're in parent
+        close(end_proc_detect[1]); // close writing side
+        data->tag = gdk_input_add(end_proc_detect[0], GDK_INPUT_READ,
+                GTK_EndProcessDetector, (gpointer)data);
+        data->pid = pid;
+        if (!sync)
+        {
+            data->process = process;
+        }
+        else
+        {
+            data->process = (wxProcess *) NULL;
+            data->pid = -(data->pid);
+
+            while (data->pid != 0)
+                wxYield();
+
+            delete data;
+        }
+
+        // @@@ our return value indicates success even if execvp() in the child
+        //     failed!
+        return pid;
     }
 }
 
@@ -389,7 +392,7 @@ long wxExecute( const wxString& command, bool sync, wxProcess *process )
         /* loop */ ;
 
     long lRc = wxExecute(argv, sync, process);
-    
+
     delete [] tmp;
 
     return lRc;
diff --git a/src/gtk1/utilsgtk.cpp b/src/gtk1/utilsgtk.cpp
index ba3988e154..fd92f99ba4 100644
--- a/src/gtk1/utilsgtk.cpp
+++ b/src/gtk1/utilsgtk.cpp
@@ -96,7 +96,7 @@ int wxGetOsVersion(int *majorVsn, int *minorVsn)
 {
   if (majorVsn) *majorVsn = GTK_MAJOR_VERSION;
   if (minorVsn) *minorVsn = GTK_MINOR_VERSION;
-  
+
   return wxGTK;
 }
 
@@ -123,11 +123,11 @@ char *wxGetUserHome( const wxString &user )
 	{
             return ptr;
 	}
-        if ((ptr = getenv("USER")) != NULL || (ptr = getenv("LOGNAME")) != NULL) 
+        if ((ptr = getenv("USER")) != NULL || (ptr = getenv("LOGNAME")) != NULL)
 	{
             who = getpwnam(ptr);
         }
-	
+
         /* We now make sure the the user exists! */
         if (who == NULL)
 	{
@@ -299,10 +299,10 @@ long wxExecute( char **argv, bool sync, wxProcess *process )
     wxCHECK_MSG( *argv, 0, "can't exec empty command" );
 
     /* Create pipes */
-    if (pipe(end_proc_detect) == -1) 
+    if (pipe(end_proc_detect) == -1)
     {
-      wxLogSysError( "Pipe creation failed" );
-      return 0;
+        wxLogSysError( "Pipe creation failed" );
+        return 0;
     }
 
     /* fork the process */
@@ -311,65 +311,68 @@ long wxExecute( char **argv, bool sync, wxProcess *process )
 #else
     pid_t pid = fork();
 #endif
-    if (pid == -1) 
+    if (pid == -1)
     {
         wxLogSysError( "Fork failed" );
         return 0;
     }
-    else if (pid == 0) 
+    else if (pid == 0)
     {
         // we're in child
         close(end_proc_detect[0]); // close reading side
-	// These three lines close the open file descriptors to
-	// to avoid any input/output which might block the process
-	// or irritate the user. If one wants proper IO for the sub-
-	// process, the "right thing to do" is to start an xterm executing
-	// it.
-	close(STDIN_FILENO);
-	close(STDOUT_FILENO);
-	close(STDERR_FILENO);
+
+        // These three lines close the open file descriptors to
+        // to avoid any input/output which might block the process
+        // or irritate the user. If one wants proper IO for the sub-
+        // process, the "right thing to do" is to start an xterm executing
+        // it.
+        close(STDIN_FILENO);
+        close(STDOUT_FILENO);
+        close(STDERR_FILENO);
+
         // some programs complain about sterr not being open, so
         // redirect them:
         open("/dev/null", O_RDONLY);  // stdin
-	open("/dev/null", O_WRONLY);  // stdout
-	open("/dev/null", O_WRONLY);  // stderr
-        
+        open("/dev/null", O_WRONLY);  // stdout
+        open("/dev/null", O_WRONLY);  // stderr
+
 
 #ifdef _AIX
         execvp ((const char *)*argv, (const char **)argv);
 #else
         execvp (*argv, argv);
 #endif
+
         // there is no return after successful exec()
         wxLogSysError( "Can't execute '%s'", *argv);
 
         _exit(-1);
     }
-    else 
+    else
     {
-      // we're in parent
-      close(end_proc_detect[1]); // close writing side
-      data->tag = gdk_input_add(end_proc_detect[0], GDK_INPUT_READ,
-                                GTK_EndProcessDetector, (gpointer)data);
-      data->pid = pid;
-      if (!sync) 
-      {
-        data->process = process;
-      }
-      else 
-      {
-        data->process = (wxProcess *) NULL;
-        data->pid = -(data->pid);
-
-        while (data->pid != 0)
-          wxYield();
-
-        delete data;
-      }
-
-      // @@@ our return value indicates success even if execvp() in the child
-      //     failed!
-      return pid;
+        // we're in parent
+        close(end_proc_detect[1]); // close writing side
+        data->tag = gdk_input_add(end_proc_detect[0], GDK_INPUT_READ,
+                GTK_EndProcessDetector, (gpointer)data);
+        data->pid = pid;
+        if (!sync)
+        {
+            data->process = process;
+        }
+        else
+        {
+            data->process = (wxProcess *) NULL;
+            data->pid = -(data->pid);
+
+            while (data->pid != 0)
+                wxYield();
+
+            delete data;
+        }
+
+        // @@@ our return value indicates success even if execvp() in the child
+        //     failed!
+        return pid;
     }
 }
 
@@ -389,7 +392,7 @@ long wxExecute( const wxString& command, bool sync, wxProcess *process )
         /* loop */ ;
 
     long lRc = wxExecute(argv, sync, process);
-    
+
     delete [] tmp;
 
     return lRc;
-- 
2.50.0

