From e6045e08ed5218ad303ee1f3cb70dd2ad621b322 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Wed, 17 Feb 1999 21:04:47 +0000
Subject: [PATCH] wxExecute() fixes and doc updates: the return value for sync
 exec case is now the exit code of the process and not its pid. Warning: MSW
 code is untested.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@1712 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 docs/latex/wx/function.tex | 10 ++++++---
 src/gtk/utilsgtk.cpp       | 44 +++++++++++++++++++++++++++-----------
 src/gtk1/utilsgtk.cpp      | 44 +++++++++++++++++++++++++++-----------
 src/msw/utilsexc.cpp       | 40 +++++++++++++++++++++++-----------
 4 files changed, 98 insertions(+), 40 deletions(-)

diff --git a/docs/latex/wx/function.tex b/docs/latex/wx/function.tex
index d4888be1db..fe92c20c42 100644
--- a/docs/latex/wx/function.tex
+++ b/docs/latex/wx/function.tex
@@ -946,9 +946,13 @@ 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.
 
-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.
+In the case of synchronous execution, the return value is trhe exit code of
+the process (which terminates by the moment the function returns) and will be
+$-1$ if the process couldn't be started and typically 0 if the process
+terminated successfully.
+
+For asynchronous execution, however, the return value is the process id and
+zero value indicates that the command could not be executed.
 
 If callback isn't NULL and if execution is asynchronous (note that callback
 parameter can not be non NULL for synchronous execution), 
diff --git a/src/gtk/utilsgtk.cpp b/src/gtk/utilsgtk.cpp
index 9f16f5c0d1..a280a4c189 100644
--- a/src/gtk/utilsgtk.cpp
+++ b/src/gtk/utilsgtk.cpp
@@ -252,10 +252,14 @@ bool wxDirExists( const wxString& dir )
 // subprocess routines
 //------------------------------------------------------------------------
 
+// if pid > 0, the execution is async and the data is freed in
+// GTK_EndProcessDetector, if pid < 0, the execution is synchronous and the
+// caller (wxExecute) frees the data
 struct wxEndProcessData
 {
     gint pid, tag;
     wxProcess *process;
+    int  exitcode;
 };
 
 static void GTK_EndProcessDetector(gpointer data, gint source,
@@ -274,7 +278,7 @@ static void GTK_EndProcessDetector(gpointer data, gint source,
     //     one)
     int status = -1;
 #if !defined(__sgi)
-    wait4(proc_data->pid, &status, 0, (rusage *) NULL);
+    wait4(pid, &status, 0, (rusage *) NULL);
 #else
     wait3(&status, 0, (rusage *) NULL);
 #endif
@@ -286,9 +290,16 @@ static void GTK_EndProcessDetector(gpointer data, gint source,
         proc_data->process->OnTerminate(proc_data->pid, status);
 
     if (proc_data->pid > 0)
+    {
         delete proc_data;
+    }
     else
+    {
+        // wxExecute() will know about it
+        proc_data->exitcode = status;
+
         proc_data->pid = 0;
+    }
 }
 
 long wxExecute( char **argv, bool sync, wxProcess *process )
@@ -356,25 +367,34 @@ long wxExecute( char **argv, bool sync, wxProcess *process )
         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
+        if ( sync )
         {
-            data->process = process;
-            data->pid = -(data->pid);
+            wxASSERT_MSG( !process, "wxProcess param ignored for sync exec" );
+            data->process = NULL;
+
+            // sync execution: indicate it by negating the pid
+            data->pid = -pid;
 
+            // it will be set to 0 from GTK_EndProcessDetector
             while (data->pid != 0)
                 wxYield();
 
+            int exitcode = data->exitcode;
+
             delete data;
+
+            return exitcode;
         }
+        else
+        {
+            // async execution, nothing special to do - caller will be
+            // notified about the process terminationif process != NULL, data
+            // will be deleted in GTK_EndProcessDetector
+            data->process = process;
+            data->pid = pid;
 
-        // @@@ our return value indicates success even if execvp() in the child
-        //     failed!
-        return pid;
+            return pid;
+        }
     }
 }
 
diff --git a/src/gtk1/utilsgtk.cpp b/src/gtk1/utilsgtk.cpp
index 9f16f5c0d1..a280a4c189 100644
--- a/src/gtk1/utilsgtk.cpp
+++ b/src/gtk1/utilsgtk.cpp
@@ -252,10 +252,14 @@ bool wxDirExists( const wxString& dir )
 // subprocess routines
 //------------------------------------------------------------------------
 
+// if pid > 0, the execution is async and the data is freed in
+// GTK_EndProcessDetector, if pid < 0, the execution is synchronous and the
+// caller (wxExecute) frees the data
 struct wxEndProcessData
 {
     gint pid, tag;
     wxProcess *process;
+    int  exitcode;
 };
 
 static void GTK_EndProcessDetector(gpointer data, gint source,
@@ -274,7 +278,7 @@ static void GTK_EndProcessDetector(gpointer data, gint source,
     //     one)
     int status = -1;
 #if !defined(__sgi)
-    wait4(proc_data->pid, &status, 0, (rusage *) NULL);
+    wait4(pid, &status, 0, (rusage *) NULL);
 #else
     wait3(&status, 0, (rusage *) NULL);
 #endif
@@ -286,9 +290,16 @@ static void GTK_EndProcessDetector(gpointer data, gint source,
         proc_data->process->OnTerminate(proc_data->pid, status);
 
     if (proc_data->pid > 0)
+    {
         delete proc_data;
+    }
     else
+    {
+        // wxExecute() will know about it
+        proc_data->exitcode = status;
+
         proc_data->pid = 0;
+    }
 }
 
 long wxExecute( char **argv, bool sync, wxProcess *process )
@@ -356,25 +367,34 @@ long wxExecute( char **argv, bool sync, wxProcess *process )
         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
+        if ( sync )
         {
-            data->process = process;
-            data->pid = -(data->pid);
+            wxASSERT_MSG( !process, "wxProcess param ignored for sync exec" );
+            data->process = NULL;
+
+            // sync execution: indicate it by negating the pid
+            data->pid = -pid;
 
+            // it will be set to 0 from GTK_EndProcessDetector
             while (data->pid != 0)
                 wxYield();
 
+            int exitcode = data->exitcode;
+
             delete data;
+
+            return exitcode;
         }
+        else
+        {
+            // async execution, nothing special to do - caller will be
+            // notified about the process terminationif process != NULL, data
+            // will be deleted in GTK_EndProcessDetector
+            data->process = process;
+            data->pid = pid;
 
-        // @@@ our return value indicates success even if execvp() in the child
-        //     failed!
-        return pid;
+            return pid;
+        }
     }
 }
 
diff --git a/src/msw/utilsexc.cpp b/src/msw/utilsexc.cpp
index 730828e34e..e54f9811fe 100644
--- a/src/msw/utilsexc.cpp
+++ b/src/msw/utilsexc.cpp
@@ -110,7 +110,7 @@ static DWORD wxExecuteThread(wxExecuteData *data)
 
     // send a message indicating process termination to the window
     SendMessage(data->hWnd, wxWM_PROC_TERMINATED, 0, (LPARAM)data);
-    
+
     return 0;
 }
 #endif
@@ -130,7 +130,7 @@ LRESULT APIENTRY _EXPORT wxExecuteWindowCbk(HWND hWnd, UINT message,
             data->handler->OnTerminate((int)data->dwProcessId,
                                        (int)data->dwExitCode);
         }
-        
+
         if ( data->state )
         {
             // we're executing synchronously, tell the waiting thread
@@ -203,7 +203,7 @@ long wxExecute(const wxString& command, bool sync, wxProcess *handler)
     result = ShellExecute(hwndTop, "open", commandName,
                           commandArgs, NULL, SW_SHOWNORMAL);
 #endif // GNUWIN32
-    
+
     if ( ((long)result) <= 32 )
         wxLogSysError(_("Can't execute command '%s'"), command.c_str());
 
@@ -248,19 +248,29 @@ long wxExecute(const wxString& command, bool sync, wxProcess *handler)
     HWND hwnd = ::CreateWindow(wxPanelClassName, NULL, 0, 0, 0, 0, 0, NULL,
                                (HMENU)NULL, wxGetInstance(), 0);
     wxASSERT_MSG( hwnd, "can't create a hidden window for wxExecute" );
-    
+
     FARPROC ExecuteWindowInstance = MakeProcInstance((FARPROC)wxExecuteWindowCbk,
                                                      wxGetInstance());
-    
+
     ::SetWindowLong(hwnd, GWL_WNDPROC, (LONG) ExecuteWindowInstance);
-    
+
     // Alloc data
     wxExecuteData *data = new wxExecuteData;
     data->hProcess    = pi.hProcess;
     data->dwProcessId = pi.dwProcessId;
     data->hWnd        = hwnd;
     data->state       = sync;
-    data->handler     = handler;
+    if ( sync )
+    {
+        wxASSERT_MSG( !handler, "wxProcess param ignored for sync execution" );
+
+        data->handler = NULL;
+    }
+    else
+    {
+        // may be NULL or not
+        data->handler = handler;
+    }
 
     DWORD tid;
     HANDLE hThread = ::CreateThread(NULL,
@@ -280,25 +290,29 @@ long wxExecute(const wxString& command, bool sync, wxProcess *handler)
         // the process still started up successfully...
         return pi.dwProcessId;
     }
-    
+
     if ( !sync )
     {
         // clean up will be done when the process terminates
+
+        // return the pid
         return pi.dwProcessId;
     }
-    
+
     // waiting until command executed
     while ( data->state )
         wxYield();
-    
+
+    DWORD dwExitCode = data->dwExitCode;
     delete data;
 
-    return pi.dwProcessId;
+    // return the exit code
+    return dwExitCode;
 #endif // 0/1
 #else // Win16
     long instanceID = WinExec((LPCSTR) WXSTRINGCAST command, SW_SHOW);
     if (instanceID < 32) return(0);
-    
+
     if (sync) {
         int running;
         do {
@@ -314,7 +328,7 @@ long wxExecute(const wxString& command, bool sync, wxProcess *handler)
 long wxExecute(char **argv, bool sync, wxProcess *handler)
 {
     wxString command;
-    
+
     while ( *argv != NULL )
     {
         command << *argv++ << ' ';
-- 
2.50.0

