]> git.saurik.com Git - wxWidgets.git/blobdiff - src/msw/utilsexc.cpp
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[wxWidgets.git] / src / msw / utilsexc.cpp
index c9ef40cab63033033830f865fc8806810a50506c..453b7efc5d82151bde76325650bafc3240c0027d 100644 (file)
@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////
-// Name:        utilsexec.cpp
+// Name:        msw/utilsexec.cpp
 // Purpose:     Various utilities
 // Author:      Julian Smart
 // Modified by:
 // Purpose:     Various utilities
 // Author:      Julian Smart
 // Modified by:
@@ -9,48 +9,55 @@
 // Licence:     wxWindows license
 /////////////////////////////////////////////////////////////////////////////
 
 // Licence:     wxWindows license
 /////////////////////////////////////////////////////////////////////////////
 
+// ============================================================================
+// declarations
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
 #ifdef __GNUG__
 #ifdef __GNUG__
-#pragma implementation
+    #pragma implementation
 #endif
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
 #endif
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
-#pragma hdrstop
+    #pragma hdrstop
 #endif
 
 #ifndef WX_PRECOMP
 #endif
 
 #ifndef WX_PRECOMP
-#include "wx/setup.h"
-#include "wx/utils.h"
-#include "wx/app.h"
-#include "wx/intl.h"
+    #include "wx/utils.h"
+    #include "wx/app.h"
+    #include "wx/intl.h"
 #endif
 
 #include "wx/log.h"
 #endif
 
 #include "wx/log.h"
-#include "wx/process.h"
 
 
-#include "wx/msw/private.h"
+#ifdef __WIN32__
+    #include "wx/stream.h"
+    #include "wx/process.h"
+#endif
 
 
-#include <windows.h>
+#include "wx/msw/private.h"
 
 #include <ctype.h>
 
 
 #include <ctype.h>
 
-#if !defined(__GNUWIN32__) && !defined(__SALFORDC__)
-#include <direct.h>
+#if !defined(__GNUWIN32__) && !defined(__WXWINE__) && !defined(__SALFORDC__)
+    #include <direct.h>
 #ifndef __MWERKS__
 #ifndef __MWERKS__
-#include <dos.h>
+    #include <dos.h>
 #endif
 #endif
 
 #endif
 #endif
 
-#ifdef __GNUWIN32__
-#ifndef __TWIN32__
-#include <sys/unistd.h>
-#include <sys/stat.h>
-#endif
+#if defined(__GNUWIN32__) && !defined(__TWIN32__)
+    #include <sys/unistd.h>
+    #include <sys/stat.h>
 #endif
 
 #endif
 
-#ifdef __WIN32__
+#if defined(__WIN32__) && !defined(__WXWINE__)
 #include <io.h>
 
 #ifndef __GNUWIN32__
 #include <io.h>
 
 #ifndef __GNUWIN32__
 #endif
 #include <stdarg.h>
 
 #endif
 #include <stdarg.h>
 
-#define wxEXECUTE_WIN_MESSAGE 10000
+#if wxUSE_IPC
+    #include "wx/dde.h"         // for WX_DDE hack in wxExecute
+#endif // wxUSE_IPC
+
+// ----------------------------------------------------------------------------
+// constants
+// ----------------------------------------------------------------------------
 
 
-struct wxExecuteData {
-  HWND window;
-  HINSTANCE process;
-  wxProcess *handler;
-  char state;
+// this message is sent when the process we're waiting for terminates
+#define wxWM_PROC_TERMINATED (WM_USER + 10000)
+
+// ----------------------------------------------------------------------------
+// this module globals
+// ----------------------------------------------------------------------------
+
+// we need to create a hidden window to receive the process termination
+// notifications and for this we need a (Win) class name for it which we will
+// register the first time it's needed
+static const wxChar *gs_classForHiddenWindow = NULL;
+
+// ----------------------------------------------------------------------------
+// private types
+// ----------------------------------------------------------------------------
+
+// structure describing the process we're being waiting for
+struct wxExecuteData
+{
+public:
+    ~wxExecuteData()
+    {
+#ifndef __WIN16__
+        if ( !::CloseHandle(hProcess) )
+        {
+            wxLogLastError("CloseHandle(hProcess)");
+        }
+#endif
+    }
+
+    HWND       hWnd;          // window to send wxWM_PROC_TERMINATED to
+    HANDLE     hProcess;      // handle of the process
+    DWORD      dwProcessId;   // pid of the process
+    wxProcess *handler;
+    DWORD      dwExitCode;    // the exit code of the process
+    bool       state;         // set to FALSE when the process finishes
 };
 
 
 #ifdef __WIN32__
 };
 
 
 #ifdef __WIN32__
-static DWORD wxExecuteThread(wxExecuteData *data)
+// ----------------------------------------------------------------------------
+// wxPipeStreams
+// ----------------------------------------------------------------------------
+
+class wxPipeInputStream: public wxInputStream {
+public:
+    wxPipeInputStream(HANDLE hInput);
+    ~wxPipeInputStream();
+
+protected:
+    size_t OnSysRead(void *buffer, size_t len);
+
+protected:
+    HANDLE m_hInput;
+};
+
+class wxPipeOutputStream: public wxOutputStream {
+public:
+    wxPipeOutputStream(HANDLE hOutput);
+    ~wxPipeOutputStream();
+
+protected:
+    size_t OnSysWrite(const void *buffer, size_t len);
+
+protected:
+    HANDLE m_hOutput;
+};
+
+// ==================
+// wxPipeInputStream
+// ==================
+
+wxPipeInputStream::wxPipeInputStream(HANDLE hInput)
 {
 {
-  WaitForSingleObject(data->process, INFINITE);
+    m_hInput = hInput;
+}
 
 
-  // Send an implicit message to the window
-  SendMessage(data->window, wxEXECUTE_WIN_MESSAGE, 0, (LPARAM)data);
+wxPipeInputStream::~wxPipeInputStream()
+{
+    ::CloseHandle(m_hInput);
+}
 
 
-  return 0;
+size_t wxPipeInputStream::OnSysRead(void *buffer, size_t len)
+{
+    DWORD bytesRead;
+
+    m_lasterror = wxSTREAM_NOERROR;
+    if (! ::ReadFile(m_hInput, buffer, len, &bytesRead, NULL) ) {
+        if (GetLastError() == ERROR_BROKEN_PIPE)
+            m_lasterror = wxSTREAM_EOF;
+        else
+            m_lasterror = wxSTREAM_READ_ERROR;
+    }
+    return bytesRead;
 }
 }
-#endif
 
 
+// ==================
+// wxPipeOutputStream
+// ==================
 
 
-LRESULT APIENTRY _EXPORT wxExecuteWindowCbk(HWND hWnd, UINT message,
-                                            WPARAM wParam, LPARAM lParam)
+wxPipeOutputStream::wxPipeOutputStream(HANDLE hOutput)
 {
 {
-  wxExecuteData *data = (wxExecuteData *)lParam;
+    m_hOutput = hOutput;
+}
 
 
-  if (message == wxEXECUTE_WIN_MESSAGE) {
-    DestroyWindow(hWnd);
-    if (data->handler)
-      data->handler->OnTerminate((int)data->process, -1);
+wxPipeOutputStream::~wxPipeOutputStream()
+{
+    ::CloseHandle(m_hOutput);
+}
 
 
-    if (data->state)
-      data->state = 0;
-    else
-      delete data;
-  }
-  return 0;
+size_t wxPipeOutputStream::OnSysWrite(const void *buffer, size_t len)
+{
+    DWORD bytesRead;
+
+    m_lasterror = wxSTREAM_NOERROR;
+    if (! ::WriteFile(m_hOutput, buffer, len, &bytesRead, NULL) ) {
+        if (GetLastError() == ERROR_BROKEN_PIPE)
+            m_lasterror = wxSTREAM_EOF;
+        else
+            m_lasterror = wxSTREAM_READ_ERROR;
+    }
+    return bytesRead;
 }
 
 }
 
-extern char wxPanelClassName[];
+#endif // __WIN32__
+
+// ============================================================================
+// implementation
+// ============================================================================
 
 
-long wxExecute(const wxString& command, bool sync, wxProcess *handler)
+#ifdef __WIN32__
+static DWORD wxExecuteThread(wxExecuteData *data)
 {
 {
-  if (command == "")
+    WaitForSingleObject(data->hProcess, INFINITE);
+
+    // get the exit code
+    if ( !GetExitCodeProcess(data->hProcess, &data->dwExitCode) )
+    {
+        wxLogLastError("GetExitCodeProcess");
+    }
+
+    wxASSERT_MSG( data->dwExitCode != STILL_ACTIVE,
+                  wxT("process should have terminated") );
+
+    // send a message indicating process termination to the window
+    SendMessage(data->hWnd, wxWM_PROC_TERMINATED, 0, (LPARAM)data);
+
     return 0;
     return 0;
+}
 
 
-#if defined(__WIN32__) && !defined(__TWIN32__)
-  char * cl;
-  char * argp;
-  int clen;
-  HINSTANCE result;
-  DWORD dresult;
-  HWND window;
-  wxExecuteData *data;
-  DWORD tid;
-
-  // copy the command line
-  clen = command.Length();
-  if (!clen) return -1;
-  cl = (char *) calloc( 1, 256);
-  if (!cl) return -1;
-  strcpy( cl, WXSTRINGCAST command);
-
-  // isolate command and arguments
-  argp = strchr( cl, ' ');
-  if (argp)
-    *argp++ = '\0';
+// window procedure of a hidden window which is created just to receive
+// the notification message when a process exits
+LRESULT APIENTRY _EXPORT wxExecuteWindowCbk(HWND hWnd, UINT message,
+                                            WPARAM wParam, LPARAM lParam)
+{
+    if ( message == wxWM_PROC_TERMINATED )
+    {
+        DestroyWindow(hWnd);    // we don't need it any more
+
+        wxExecuteData *data = (wxExecuteData *)lParam;
+        if ( data->handler )
+        {
+            data->handler->OnTerminate((int)data->dwProcessId,
+                                       (int)data->dwExitCode);
+        }
+
+        if ( data->state )
+        {
+            // we're executing synchronously, tell the waiting thread
+            // that the process finished
+            data->state = 0;
+        }
+        else
+        {
+            // asynchronous execution - we should do the clean up
+            delete data;
+        }
+
+        return 0;
+    }
+    else
+    {
+        return DefWindowProc(hWnd, message, wParam, lParam);
+    }
+}
+#endif // Win32
 
 
-#ifdef __GNUWIN32__
-  result = ShellExecute((HWND) (wxTheApp->GetTopWindow() ? (HWND) wxTheApp->GetTopWindow()->GetHWND() : NULL),
-     (const wchar_t) "open", (const wchar_t) cl, (const wchar_t) argp,
-     (const wchar_t) NULL, SW_SHOWNORMAL);
-#else
-  result = ShellExecute( (HWND) (wxTheApp->GetTopWindow() ? wxTheApp->GetTopWindow()->GetHWND() : NULL),
-     "open", cl, argp, NULL, SW_SHOWNORMAL);
-#endif
+long wxExecute(const wxString& cmd, bool sync, wxProcess *handler)
+{
+    wxCHECK_MSG( !!cmd, 0, wxT("empty command in wxExecute") );
+
+    wxString command;
+#if wxUSE_IPC
+    // DDE hack: this is really not pretty, but we need to allow this for
+    // transparent handling of DDE servers in wxMimeTypesManager. Usually it
+    // returns the command which should be run to view/open/... a file of the
+    // given type. Sometimes, however, this command just launches the server
+    // and an additional DDE request must be made to really open the file. To
+    // keep all this well hidden from the application, we allow a special form
+    // of command: WX_DDE:<command>:DDE_SERVER:DDE_TOPIC:DDE_COMMAND in which
+    // case we execute just <command> and process the rest below
+    wxString ddeServer, ddeTopic, ddeCommand;
+    static const size_t lenDdePrefix = 7;   // strlen("WX_DDE:")
+    if ( cmd.Left(lenDdePrefix) == _T("WX_DDE#") )
+    {
+        const wxChar *p = cmd.c_str() + 7;
+        while ( *p && *p != _T('#') )
+        {
+            command += *p++;
+        }
+
+        if ( *p )
+        {
+            // skip '#'
+            p++;
+        }
+        else
+        {
+            wxFAIL_MSG(_T("invalid WX_DDE command in wxExecute"));
+        }
+
+        while ( *p && *p != _T('#') )
+        {
+            ddeServer += *p++;
+        }
+
+        if ( *p )
+        {
+            // skip '#'
+            p++;
+        }
+        else
+        {
+            wxFAIL_MSG(_T("invalid WX_DDE command in wxExecute"));
+        }
+
+        while ( *p && *p != _T('#') )
+        {
+            ddeTopic += *p++;
+        }
+
+        if ( *p )
+        {
+            // skip '#'
+            p++;
+        }
+        else
+        {
+            wxFAIL_MSG(_T("invalid WX_DDE command in wxExecute"));
+        }
+
+        while ( *p )
+        {
+            ddeCommand += *p++;
+        }
+    }
+    else
+#endif // wxUSE_IPC
+    {
+        // no DDE
+        command = cmd;
+    }
 
 
-  if (((long)result) <= 32) {
-   free(cl);
-
-   wxLogSysError(_("Can't execute command '%s'"), command.c_str());
-   return 0;
-  }
-
-  // Alloc data
-  data = new wxExecuteData;
-
-  // Create window
-  window = CreateWindow(wxPanelClassName, NULL, 0, 0, 0, 0, 0, NULL,
-                        (HMENU) NULL, wxGetInstance(), 0);
-
-  FARPROC ExecuteWindowInstance = MakeProcInstance((FARPROC) wxExecuteWindowCbk,
-                                                   wxGetInstance());
-
-  SetWindowLong(window, GWL_WNDPROC, (LONG) ExecuteWindowInstance);
-  SetWindowLong(window, GWL_USERDATA, (LONG) data);
-
-  data->process = result;
-  data->window  = window;
-  data->state   = sync;
-  data->handler = (sync) ? NULL : handler;
-
-  dresult = (DWORD)CreateThread(NULL, 0,
-                                (LPTHREAD_START_ROUTINE)wxExecuteThread,
-                                (void *)data, 0, &tid);
-  if (dresult == 0) {
-    wxDebugMsg("wxExecute PANIC: I can't create the waiting thread !"); 
-    DestroyWindow(window);
-    return (long)result;
-  }
-
-  if (!sync)
-  {
-    free(cl);
-    return (long)result;
-  }
-
-  // waiting until command executed
-  while (data->state)
-    wxYield();
-
-  free(cl);
-  return 0;
-#else
-  long instanceID = WinExec((LPCSTR) WXSTRINGCAST command, SW_SHOW);
-  if (instanceID < 32) return(0);
-
-  if (sync) {
-    int running;
-    do {
-      wxYield();
-      running = GetModuleUsage((HANDLE)instanceID);
-    } while (running);
-  }
-  return(instanceID);
-#endif
+#if defined(__WIN32__) && !defined(__TWIN32__)
+    // the old code is disabled because we really need a process handle
+    // if we want to execute it asynchronously or even just get its
+    // return code and for this we must use CreateProcess() and not
+    // ShellExecute()
+#if 0
+    // isolate command and arguments
+    wxString commandName;
+    bool insideQuotes = FALSE;
+    const char *pc;
+    for ( pc = command.c_str(); *pc != '\0'; pc++ )
+    {
+        switch ( *pc )
+        {
+            case ' ':
+            case '\t':
+                if ( !insideQuotes )
+                    break;
+                // fall through
+
+            case '"':
+                insideQuotes = !insideQuotes;
+                // fall through
+
+            default:
+                commandName += *pc;
+                continue;   // skip the next break
+        }
+
+        // only reached for space not inside quotes
+        break;
+    }
+    wxString commandArgs = pc;
+
+    wxWindow *winTop = wxTheApp->GetTopWindow();
+    HWND hwndTop = (HWND)(winTop ? winTop->GetHWND() : 0);
+
+    HANDLE result;
+#ifdef __GNUWIN32__
+    result = ShellExecute(hwndTop,
+                          (const wchar_t)"open",
+                          (const wchar_t)commandName,
+                          (const wchar_t)commandArgs,
+                          (const wchar_t)NULL,
+                          SW_SHOWNORMAL);
+#else // !GNUWIN32
+    result = ShellExecute(hwndTop, "open", commandName,
+                          commandArgs, NULL, SW_SHOWNORMAL);
+#endif // GNUWIN32
+
+    if ( ((long)result) <= 32 )
+        wxLogSysError(_("Can't execute command '%s'"), command.c_str());
+
+    return result;
+#else // 1
+
+    HANDLE hpipeRead[2];
+    HANDLE hpipeWrite[2];
+    HANDLE hStdIn = INVALID_HANDLE_VALUE;
+    HANDLE hStdOut = INVALID_HANDLE_VALUE;
+
+    // we need to inherit handles in the child process if we want to redirect
+    // its IO
+    BOOL inheritHandles = FALSE;
+
+    // open the pipes to which child process IO will be redirected if needed
+    if ( handler && handler->IsRedirected() )
+    {
+        SECURITY_ATTRIBUTES security;
+
+        security.nLength              = sizeof(security);
+        security.lpSecurityDescriptor = NULL;
+        security.bInheritHandle       = TRUE;
+
+        if ( !::CreatePipe(&hpipeRead[0], &hpipeRead[1], &security, 0) )
+        {
+            wxLogSysError(_("Can't create the inter-process read pipe"));
+
+            return 0;
+        }
+
+        if ( !::CreatePipe(&hpipeWrite[0], &hpipeWrite[1], &security, 0) )
+        {
+            ::CloseHandle(hpipeRead[0]);
+            ::CloseHandle(hpipeRead[1]);
+
+            wxLogSysError(_("Can't create the inter-process write pipe"));
+
+            return 0;
+        }
+
+        // We need to save the old stdio handles to restore them after the call
+        // to CreateProcess
+        hStdIn  = ::GetStdHandle(STD_INPUT_HANDLE);
+        hStdOut = ::GetStdHandle(STD_OUTPUT_HANDLE);
+
+        if ( !::SetStdHandle(STD_INPUT_HANDLE, hpipeRead[0]) ||
+             !::SetStdHandle(STD_OUTPUT_HANDLE, hpipeWrite[1]) )
+        {
+            wxLogDebug(_T("Failed to change stdin/out handles"));
+        }
+
+        inheritHandles = TRUE;
+    }
+
+    // create the process
+    STARTUPINFO si;
+    wxZeroMemory(si);
+
+    si.cb = sizeof(si);
+
+    PROCESS_INFORMATION pi;
+
+    if ( ::CreateProcess(
+                         NULL,       // application name (use only cmd line)
+                         (wxChar *)command.c_str(),  // full command line
+                         NULL,       // security attributes: defaults for both
+                         NULL,       //   the process and its main thread
+                         inheritHandles,      // inherit handles if we need pipes
+                         CREATE_DEFAULT_ERROR_MODE |
+                         CREATE_SUSPENDED,           // flags
+                         NULL,       // environment (use the same)
+                         NULL,       // current directory (use the same)
+                         &si,        // startup info (unused here)
+                         &pi         // process info
+                        ) == 0 )
+    {
+        if ( inheritHandles )
+        {
+            ::CloseHandle(hpipeWrite[0]);
+            ::CloseHandle(hpipeWrite[1]);
+            ::CloseHandle(hpipeRead[0]);
+            ::CloseHandle(hpipeRead[1]);
+        }
+
+        wxLogSysError(_("Execution of command '%s' failed"), command.c_str());
+
+        return 0;
+    }
+
+    // Restore the old stdio handles
+    if ( inheritHandles )
+    {
+        if ( !::SetStdHandle(STD_INPUT_HANDLE, hStdIn) ||
+             !::SetStdHandle(STD_OUTPUT_HANDLE, hStdOut) )
+        {
+            wxLogDebug(_T("Failed to restore old stdin/out handles"));
+        }
+
+        // they're still opened in child process
+        ::CloseHandle(hpipeWrite[1]);
+        ::CloseHandle(hpipeRead[0]);
+
+        // We can now initialize the wxStreams
+        wxInputStream *inStream = new wxPipeInputStream(hpipeWrite[0]);
+        wxOutputStream *outStream = new wxPipeOutputStream(hpipeRead[1]);
+
+        handler->SetPipeStreams(inStream, outStream);
+    }
+
+    // register the class for the hidden window used for the notifications
+    if ( !gs_classForHiddenWindow )
+    {
+        gs_classForHiddenWindow = _T("wxHiddenWindow");
+
+        WNDCLASS wndclass;
+        wxZeroMemory(wndclass);
+        wndclass.lpfnWndProc   = (WNDPROC)wxExecuteWindowCbk;
+        wndclass.hInstance     = wxGetInstance();
+        wndclass.lpszClassName = gs_classForHiddenWindow;
+
+        if ( !::RegisterClass(&wndclass) )
+        {
+            wxLogLastError("RegisterClass(hidden window)");
+        }
+    }
+
+    // create a hidden window to receive notification about process
+    // termination
+    HWND hwnd = ::CreateWindow(gs_classForHiddenWindow, NULL,
+                               WS_OVERLAPPEDWINDOW,
+                               0, 0, 0, 0, NULL,
+                               (HMENU)NULL, wxGetInstance(), 0);
+    wxASSERT_MSG( hwnd, wxT("can't create a hidden window for wxExecute") );
+
+    // Alloc data
+    wxExecuteData *data = new wxExecuteData;
+    data->hProcess    = pi.hProcess;
+    data->dwProcessId = pi.dwProcessId;
+    data->hWnd        = hwnd;
+    data->state       = sync;
+    if ( sync )
+    {
+        // handler may be !NULL for capturing program output, but we don't use
+        // it wxExecuteData struct in this case
+        data->handler = NULL;
+    }
+    else
+    {
+        // may be NULL or not
+        data->handler = handler;
+    }
+
+    DWORD tid;
+    HANDLE hThread = ::CreateThread(NULL,
+                                    0,
+                                    (LPTHREAD_START_ROUTINE)wxExecuteThread,
+                                    (void *)data,
+                                    0,
+                                    &tid);
+
+    // resume process we created now - whether the thread creation succeeded or
+    // not
+    if ( ::ResumeThread(pi.hThread) == (DWORD)-1 )
+    {
+        // ignore it - what can we do?
+        wxLogLastError("ResumeThread in wxExecute");
+    }
+
+    // close unneeded handle
+    if ( !::CloseHandle(pi.hThread) )
+        wxLogLastError("CloseHandle(hThread)");
+
+    if ( !hThread )
+    {
+        wxLogLastError("CreateThread in wxExecute");
+
+        DestroyWindow(hwnd);
+        delete data;
+
+        // the process still started up successfully...
+        return pi.dwProcessId;
+    }
+
+#if wxUSE_IPC
+    // second part of DDE hack: now establish the DDE conversation with the
+    // just launched process
+    if ( !!ddeServer )
+    {
+        wxDDEClient client;
+        wxConnectionBase *conn = client.MakeConnection(_T(""),
+                                                       ddeServer,
+                                                       ddeTopic);
+        if ( !conn || !conn->Execute(ddeCommand) )
+        {
+            wxLogError(_("Couldn't launch DDE server '%s'."), command.c_str());
+        }
+    }
+#endif // wxUSE_IPC
+
+    if ( !sync )
+    {
+        // clean up will be done when the process terminates
+
+        // return the pid
+        return pi.dwProcessId;
+    }
+
+    // waiting until command executed (disable everything while doing it)
+#if wxUSE_GUI
+    {
+        wxBusyCursor bc;
+
+        wxWindowDisabler wd;
+#endif // wxUSE_GUI
+
+    while ( data->state )
+        wxYield();
+
+#if wxUSE_GUI
+    }
+#endif // wxUSE_GUI
+
+    DWORD dwExitCode = data->dwExitCode;
+    delete data;
+
+    // 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 {
+            wxYield();
+            running = GetModuleUsage((HINSTANCE)instanceID);
+        } while (running);
+    }
+
+    return(instanceID);
+#endif // Win16/32
 }
 
 long wxExecute(char **argv, bool sync, wxProcess *handler)
 {
 }
 
 long wxExecute(char **argv, bool sync, wxProcess *handler)
 {
-  wxString command = "";
-
-  while (*argv != NULL) {
-    command += *argv;
-    command += ' ';
-    argv++;
-  }
-  command.RemoveLast();
-  return wxExecute(command, sync, handler);
+    wxString command;
+
+    while ( *argv != NULL )
+    {
+        command << *argv++ << ' ';
+    }
+
+    command.RemoveLast();
+
+    return wxExecute(command, sync, handler);
+}
+
+// ----------------------------------------------------------------------------
+// Metafile helpers
+// ----------------------------------------------------------------------------
+
+extern void PixelToHIMETRIC(LONG *x, LONG *y)
+{
+    ScreenHDC hdcRef;
+
+    int iWidthMM = GetDeviceCaps(hdcRef, HORZSIZE),
+        iHeightMM = GetDeviceCaps(hdcRef, VERTSIZE),
+        iWidthPels = GetDeviceCaps(hdcRef, HORZRES),
+        iHeightPels = GetDeviceCaps(hdcRef, VERTRES);
+
+    *x *= (iWidthMM * 100);
+    *x /= iWidthPels;
+    *y *= (iHeightMM * 100);
+    *y /= iHeightPels;
+}
+
+extern void HIMETRICToPixel(LONG *x, LONG *y)
+{
+    ScreenHDC hdcRef;
+
+    int iWidthMM = GetDeviceCaps(hdcRef, HORZSIZE),
+        iHeightMM = GetDeviceCaps(hdcRef, VERTSIZE),
+        iWidthPels = GetDeviceCaps(hdcRef, HORZRES),
+        iHeightPels = GetDeviceCaps(hdcRef, VERTRES);
+
+    *x *= iWidthPels;
+    *x /= (iWidthMM * 100);
+    *y *= iHeightPels;
+    *y /= (iHeightMM * 100);
 }
 }