src/msw/utilsexc.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        msw/utilsexec.cpp
   3 // Purpose:     wxExecute implementation for MSW
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     04/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998-2002 wxWidgets dev team
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  21     #pragma implementation
  22 #endif
  23
  24 // For compilers that support precompilation, includes "wx.h".
  25 #include "wx/wxprec.h"
  26
  27 #ifdef __BORLANDC__
  28     #pragma hdrstop
  29 #endif
  30
  31 #ifndef WX_PRECOMP
  32     #include "wx/utils.h"
  33     #include "wx/app.h"
  34     #include "wx/intl.h"
  35     #include "wx/log.h"
  36 #endif
  37
  38 #include "wx/stream.h"
  39 #include "wx/process.h"
  40
  41 #include "wx/apptrait.h"
  42
  43 #include "wx/module.h"
  44
  45 #include "wx/msw/private.h"
  46
  47 #include <ctype.h>
  48
  49 #if !defined(__GNUWIN32__) && !defined(__SALFORDC__) && !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
  50     #include <direct.h>
  51 #ifndef __MWERKS__
  52     #include <dos.h>
  53 #endif
  54 #endif
  55
  56 #if defined(__GNUWIN32__)
  57     #include <sys/unistd.h>
  58     #include <sys/stat.h>
  59 #endif
  60
  61 #if !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
  62     #ifndef __UNIX__
  63         #include <io.h>
  64     #endif
  65
  66     #ifndef __GNUWIN32__
  67         #include <shellapi.h>
  68     #endif
  69 #endif
  70
  71 #include <stdio.h>
  72 #include <stdlib.h>
  73 #include <string.h>
  74 #ifndef __WATCOMC__
  75     #if !(defined(_MSC_VER) && (_MSC_VER > 800))
  76         #include <errno.h>
  77     #endif
  78 #endif
  79 #include <stdarg.h>
  80
  81 #if wxUSE_IPC
  82     #include "wx/dde.h"         // for WX_DDE hack in wxExecute
  83 #endif // wxUSE_IPC
  84
  85 // implemented in utils.cpp
  86 extern "C" WXDLLIMPEXP_BASE HWND
  87 wxCreateHiddenWindow(LPCTSTR *pclassname, LPCTSTR classname, WNDPROC wndproc);
  88
  89 // ----------------------------------------------------------------------------
  90 // constants
  91 // ----------------------------------------------------------------------------
  92
  93 // this message is sent when the process we're waiting for terminates
  94 #define wxWM_PROC_TERMINATED (WM_USER + 10000)
  95
  96 // ----------------------------------------------------------------------------
  97 // this module globals
  98 // ----------------------------------------------------------------------------
  99
 100 // we need to create a hidden window to receive the process termination
 101 // notifications and for this we need a (Win) class name for it which we will
 102 // register the first time it's needed
 103 static const wxChar *wxMSWEXEC_WNDCLASSNAME = wxT("_wxExecute_Internal_Class");
 104 static const wxChar *gs_classForHiddenWindow = NULL;
 105
 106 // ----------------------------------------------------------------------------
 107 // private types
 108 // ----------------------------------------------------------------------------
 109
 110 // structure describing the process we're being waiting for
 111 struct wxExecuteData
 112 {
 113 public:
 114     ~wxExecuteData()
 115     {
 116         if ( !::CloseHandle(hProcess) )
 117         {
 118             wxLogLastError(wxT("CloseHandle(hProcess)"));
 119         }
 120     }
 121
 122     HWND       hWnd;          // window to send wxWM_PROC_TERMINATED to
 123     HANDLE     hProcess;      // handle of the process
 124     DWORD      dwProcessId;   // pid of the process
 125     wxProcess *handler;
 126     DWORD      dwExitCode;    // the exit code of the process
 127     bool       state;         // set to FALSE when the process finishes
 128 };
 129
 130 class wxExecuteModule : public wxModule
 131 {
 132 public:
 133     virtual bool OnInit() { return true; }
 134     virtual void OnExit()
 135     {
 136         if ( *gs_classForHiddenWindow )
 137         {
 138             if ( !::UnregisterClass(wxMSWEXEC_WNDCLASSNAME, wxGetInstance()) )
 139             {
 140                 wxLogLastError(_T("UnregisterClass(wxExecClass)"));
 141             }
 142
 143             gs_classForHiddenWindow = NULL;
 144         }
 145     }
 146
 147 private:
 148     DECLARE_DYNAMIC_CLASS(wxExecuteModule)
 149 };
 150
 151 #if wxUSE_STREAMS && !defined(__WXWINCE__)
 152
 153 // ----------------------------------------------------------------------------
 154 // wxPipeStreams
 155 // ----------------------------------------------------------------------------
 156
 157 class wxPipeInputStream: public wxInputStream
 158 {
 159 public:
 160     wxPipeInputStream(HANDLE hInput);
 161     virtual ~wxPipeInputStream();
 162
 163     // returns TRUE if the pipe is still opened
 164     bool IsOpened() const { return m_hInput != INVALID_HANDLE_VALUE; }
 165
 166     // returns TRUE if there is any data to be read from the pipe
 167     virtual bool CanRead() const;
 168
 169 protected:
 170     size_t OnSysRead(void *buffer, size_t len);
 171
 172 protected:
 173     HANDLE m_hInput;
 174
 175     DECLARE_NO_COPY_CLASS(wxPipeInputStream)
 176 };
 177
 178 class wxPipeOutputStream: public wxOutputStream
 179 {
 180 public:
 181     wxPipeOutputStream(HANDLE hOutput);
 182     virtual ~wxPipeOutputStream();
 183
 184 protected:
 185     size_t OnSysWrite(const void *buffer, size_t len);
 186
 187 protected:
 188     HANDLE m_hOutput;
 189
 190     DECLARE_NO_COPY_CLASS(wxPipeOutputStream)
 191 };
 192
 193 // define this to let wxexec.cpp know that we know what we're doing
 194 #define _WX_USED_BY_WXEXECUTE_
 195 #include "../common/execcmn.cpp"
 196
 197 // ----------------------------------------------------------------------------
 198 // wxPipe represents a Win32 anonymous pipe
 199 // ----------------------------------------------------------------------------
 200
 201 class wxPipe
 202 {
 203 public:
 204     // the symbolic names for the pipe ends
 205     enum Direction
 206     {
 207         Read,
 208         Write
 209     };
 210
 211     // default ctor doesn't do anything
 212     wxPipe() { m_handles[Read] = m_handles[Write] = INVALID_HANDLE_VALUE; }
 213
 214     // create the pipe, return TRUE if ok, FALSE on error
 215     bool Create()
 216     {
 217         // default secutiry attributes
 218         SECURITY_ATTRIBUTES security;
 219
 220         security.nLength              = sizeof(security);
 221         security.lpSecurityDescriptor = NULL;
 222         security.bInheritHandle       = TRUE; // to pass it to the child
 223
 224         if ( !::CreatePipe(&m_handles[0], &m_handles[1], &security, 0) )
 225         {
 226             wxLogSysError(_("Failed to create an anonymous pipe"));
 227
 228             return FALSE;
 229         }
 230
 231         return TRUE;
 232     }
 233
 234     // return TRUE if we were created successfully
 235     bool IsOk() const { return m_handles[Read] != INVALID_HANDLE_VALUE; }
 236
 237     // return the descriptor for one of the pipe ends
 238     HANDLE operator[](Direction which) const { return m_handles[which]; }
 239
 240     // detach a descriptor, meaning that the pipe dtor won't close it, and
 241     // return it
 242     HANDLE Detach(Direction which)
 243     {
 244         HANDLE handle = m_handles[which];
 245         m_handles[which] = INVALID_HANDLE_VALUE;
 246
 247         return handle;
 248     }
 249
 250     // close the pipe descriptors
 251     void Close()
 252     {
 253         for ( size_t n = 0; n < WXSIZEOF(m_handles); n++ )
 254         {
 255             if ( m_handles[n] != INVALID_HANDLE_VALUE )
 256             {
 257                 ::CloseHandle(m_handles[n]);
 258                 m_handles[n] = INVALID_HANDLE_VALUE;
 259             }
 260         }
 261     }
 262
 263     // dtor closes the pipe descriptors
 264     ~wxPipe() { Close(); }
 265
 266 private:
 267     HANDLE m_handles[2];
 268 };
 269
 270 #endif // wxUSE_STREAMS
 271
 272 // ============================================================================
 273 // implementation
 274 // ============================================================================
 275
 276 // ----------------------------------------------------------------------------
 277 // process termination detecting support
 278 // ----------------------------------------------------------------------------
 279
 280 // thread function for the thread monitoring the process termination
 281 static DWORD __stdcall wxExecuteThread(void *arg)
 282 {
 283     wxExecuteData * const data = (wxExecuteData *)arg;
 284
 285     if ( ::WaitForSingleObject(data->hProcess, INFINITE) != WAIT_OBJECT_0 )
 286     {
 287         wxLogDebug(_T("Waiting for the process termination failed!"));
 288     }
 289
 290     // get the exit code
 291     if ( !::GetExitCodeProcess(data->hProcess, &data->dwExitCode) )
 292     {
 293         wxLogLastError(wxT("GetExitCodeProcess"));
 294     }
 295
 296     wxASSERT_MSG( data->dwExitCode != STILL_ACTIVE,
 297                   wxT("process should have terminated") );
 298
 299     // send a message indicating process termination to the window
 300     ::SendMessage(data->hWnd, wxWM_PROC_TERMINATED, 0, (LPARAM)data);
 301
 302     return 0;
 303 }
 304
 305 // window procedure of a hidden window which is created just to receive
 306 // the notification message when a process exits
 307 LRESULT APIENTRY _EXPORT wxExecuteWindowCbk(HWND hWnd, UINT message,
 308                                             WPARAM wParam, LPARAM lParam)
 309 {
 310     if ( message == wxWM_PROC_TERMINATED )
 311     {
 312         DestroyWindow(hWnd);    // we don't need it any more
 313
 314         wxExecuteData * const data = (wxExecuteData *)lParam;
 315         if ( data->handler )
 316         {
 317             data->handler->OnTerminate((int)data->dwProcessId,
 318                                        (int)data->dwExitCode);
 319         }
 320
 321         if ( data->state )
 322         {
 323             // we're executing synchronously, tell the waiting thread
 324             // that the process finished
 325             data->state = 0;
 326         }
 327         else
 328         {
 329             // asynchronous execution - we should do the clean up
 330             delete data;
 331         }
 332
 333         return 0;
 334     }
 335     else
 336     {
 337         return ::DefWindowProc(hWnd, message, wParam, lParam);
 338     }
 339 }
 340
 341 // ============================================================================
 342 // implementation of IO redirection support classes
 343 // ============================================================================
 344
 345 #if wxUSE_STREAMS && !defined(__WXWINCE__)
 346
 347 // ----------------------------------------------------------------------------
 348 // wxPipeInputStreams
 349 // ----------------------------------------------------------------------------
 350
 351 wxPipeInputStream::wxPipeInputStream(HANDLE hInput)
 352 {
 353     m_hInput = hInput;
 354 }
 355
 356 wxPipeInputStream::~wxPipeInputStream()
 357 {
 358     if ( m_hInput != INVALID_HANDLE_VALUE )
 359         ::CloseHandle(m_hInput);
 360 }
 361
 362 bool wxPipeInputStream::CanRead() const
 363 {
 364     if ( !IsOpened() )
 365         return FALSE;
 366
 367     DWORD nAvailable;
 368
 369     // function name is misleading, it works with anon pipes as well
 370     DWORD rc = ::PeekNamedPipe
 371                     (
 372                       m_hInput,     // handle
 373                       NULL, 0,      // ptr to buffer and its size
 374                       NULL,         // [out] bytes read
 375                       &nAvailable,  // [out] bytes available
 376                       NULL          // [out] bytes left
 377                     );
 378
 379     if ( !rc )
 380     {
 381         if ( ::GetLastError() != ERROR_BROKEN_PIPE )
 382         {
 383             // unexpected error
 384             wxLogLastError(_T("PeekNamedPipe"));
 385         }
 386
 387         // don't try to continue reading from a pipe if an error occured or if
 388         // it had been closed
 389         ::CloseHandle(m_hInput);
 390
 391         wxPipeInputStream *self = wxConstCast(this, wxPipeInputStream);
 392
 393         self->m_hInput = INVALID_HANDLE_VALUE;
 394         self->m_lasterror = wxSTREAM_EOF;
 395
 396         nAvailable = 0;
 397     }
 398
 399     return nAvailable != 0;
 400 }
 401
 402 size_t wxPipeInputStream::OnSysRead(void *buffer, size_t len)
 403 {
 404     if ( !IsOpened() )
 405     {
 406         m_lasterror = wxSTREAM_EOF;
 407
 408         return 0;
 409     }
 410
 411     DWORD bytesRead;
 412     if ( !::ReadFile(m_hInput, buffer, len, &bytesRead, NULL) )
 413     {
 414         m_lasterror = ::GetLastError() == ERROR_BROKEN_PIPE
 415                         ? wxSTREAM_EOF
 416                         : wxSTREAM_READ_ERROR;
 417     }
 418
 419     // bytesRead is set to 0, as desired, if an error occured
 420     return bytesRead;
 421 }
 422
 423 // ----------------------------------------------------------------------------
 424 // wxPipeOutputStream
 425 // ----------------------------------------------------------------------------
 426
 427 wxPipeOutputStream::wxPipeOutputStream(HANDLE hOutput)
 428 {
 429     m_hOutput = hOutput;
 430 }
 431
 432 wxPipeOutputStream::~wxPipeOutputStream()
 433 {
 434     ::CloseHandle(m_hOutput);
 435 }
 436
 437 size_t wxPipeOutputStream::OnSysWrite(const void *buffer, size_t len)
 438 {
 439     DWORD bytesWritten;
 440
 441     m_lasterror = wxSTREAM_NO_ERROR;
 442     if ( !::WriteFile(m_hOutput, buffer, len, &bytesWritten, NULL) )
 443     {
 444         m_lasterror = ::GetLastError() == ERROR_BROKEN_PIPE
 445                             ? wxSTREAM_EOF
 446                             : wxSTREAM_WRITE_ERROR;
 447     }
 448
 449     return bytesWritten;
 450 }
 451
 452 #endif // wxUSE_STREAMS
 453
 454 // ============================================================================
 455 // wxExecute functions family
 456 // ============================================================================
 457
 458 #if wxUSE_IPC
 459
 460 // connect to the given server via DDE and ask it to execute the command
 461 static bool wxExecuteDDE(const wxString& ddeServer,
 462                          const wxString& ddeTopic,
 463                          const wxString& ddeCommand)
 464 {
 465     bool ok wxDUMMY_INITIALIZE(false);
 466
 467     wxDDEClient client;
 468     wxConnectionBase *conn = client.MakeConnection(wxEmptyString,
 469                                                    ddeServer,
 470                                                    ddeTopic);
 471     if ( !conn )
 472     {
 473         ok = FALSE;
 474     }
 475     else // connected to DDE server
 476     {
 477         // the added complication here is that although most programs use
 478         // XTYP_EXECUTE for their DDE API, some important ones -- like Word
 479         // and other MS stuff - use XTYP_REQUEST!
 480         //
 481         // moreover, anotheri mportant program (IE) understands both but
 482         // returns an error from Execute() so we must try Request() first
 483         // to avoid doing it twice
 484         {
 485             // we're prepared for this one to fail, so don't show errors
 486             wxLogNull noErrors;
 487
 488             ok = conn->Request(ddeCommand) != NULL;
 489         }
 490
 491         if ( !ok )
 492         {
 493             // now try execute -- but show the errors
 494             ok = conn->Execute(ddeCommand);
 495         }
 496     }
 497
 498     return ok;
 499 }
 500
 501 #endif // wxUSE_IPC
 502
 503 long wxExecute(const wxString& cmd, int flags, wxProcess *handler)
 504 {
 505     wxCHECK_MSG( !!cmd, 0, wxT("empty command in wxExecute") );
 506
 507 #if wxUSE_THREADS
 508     // for many reasons, the code below breaks down if it's called from another
 509     // thread -- this could be fixed, but as Unix versions don't support this
 510     // neither I don't want to waste time on this now
 511     wxASSERT_MSG( wxThread::IsMain(),
 512                     _T("wxExecute() can be called only from the main thread") );
 513 #endif // wxUSE_THREADS
 514
 515     wxString command;
 516
 517 #if wxUSE_IPC
 518     // DDE hack: this is really not pretty, but we need to allow this for
 519     // transparent handling of DDE servers in wxMimeTypesManager. Usually it
 520     // returns the command which should be run to view/open/... a file of the
 521     // given type. Sometimes, however, this command just launches the server
 522     // and an additional DDE request must be made to really open the file. To
 523     // keep all this well hidden from the application, we allow a special form
 524     // of command: WX_DDE#<command>#DDE_SERVER#DDE_TOPIC#DDE_COMMAND in which
 525     // case we execute just <command> and process the rest below
 526     wxString ddeServer, ddeTopic, ddeCommand;
 527     static const size_t lenDdePrefix = 7;   // strlen("WX_DDE:")
 528     if ( cmd.Left(lenDdePrefix) == _T("WX_DDE#") )
 529     {
 530         // speed up the concatenations below
 531         ddeServer.reserve(256);
 532         ddeTopic.reserve(256);
 533         ddeCommand.reserve(256);
 534
 535         const wxChar *p = cmd.c_str() + 7;
 536         while ( *p && *p != _T('#') )
 537         {
 538             command += *p++;
 539         }
 540
 541         if ( *p )
 542         {
 543             // skip '#'
 544             p++;
 545         }
 546         else
 547         {
 548             wxFAIL_MSG(_T("invalid WX_DDE command in wxExecute"));
 549         }
 550
 551         while ( *p && *p != _T('#') )
 552         {
 553             ddeServer += *p++;
 554         }
 555
 556         if ( *p )
 557         {
 558             // skip '#'
 559             p++;
 560         }
 561         else
 562         {
 563             wxFAIL_MSG(_T("invalid WX_DDE command in wxExecute"));
 564         }
 565
 566         while ( *p && *p != _T('#') )
 567         {
 568             ddeTopic += *p++;
 569         }
 570
 571         if ( *p )
 572         {
 573             // skip '#'
 574             p++;
 575         }
 576         else
 577         {
 578             wxFAIL_MSG(_T("invalid WX_DDE command in wxExecute"));
 579         }
 580
 581         while ( *p )
 582         {
 583             ddeCommand += *p++;
 584         }
 585
 586         // if we want to just launch the program and not wait for its
 587         // termination, try to execute DDE command right now, it can succeed if
 588         // the process is already running - but as it fails if it's not
 589         // running, suppress any errors it might generate
 590         if ( !(flags & wxEXEC_SYNC) )
 591         {
 592             wxLogNull noErrors;
 593             if ( wxExecuteDDE(ddeServer, ddeTopic, ddeCommand) )
 594             {
 595                 // a dummy PID - this is a hack, of course, but it's well worth
 596                 // it as we don't open a new server each time we're called
 597                 // which would be quite bad
 598                 return -1;
 599             }
 600         }
 601     }
 602     else
 603 #endif // wxUSE_IPC
 604     {
 605         // no DDE
 606         command = cmd;
 607     }
 608
 609     // the IO redirection is only supported with wxUSE_STREAMS
 610     BOOL redirect = FALSE;
 611
 612 #if wxUSE_STREAMS && !defined(__WXWINCE__)
 613     wxPipe pipeIn, pipeOut, pipeErr;
 614
 615     // we'll save here the copy of pipeIn[Write]
 616     HANDLE hpipeStdinWrite = INVALID_HANDLE_VALUE;
 617
 618     // open the pipes to which child process IO will be redirected if needed
 619     if ( handler && handler->IsRedirected() )
 620     {
 621         // create pipes for redirecting stdin, stdout and stderr
 622         if ( !pipeIn.Create() || !pipeOut.Create() || !pipeErr.Create() )
 623         {
 624             wxLogSysError(_("Failed to redirect the child process IO"));
 625
 626             // indicate failure: we need to return different error code
 627             // depending on the sync flag
 628             return flags & wxEXEC_SYNC ? -1 : 0;
 629         }
 630
 631         redirect = TRUE;
 632     }
 633 #endif // wxUSE_STREAMS
 634
 635     // create the process
 636     STARTUPINFO si;
 637     wxZeroMemory(si);
 638     si.cb = sizeof(si);
 639
 640 #if wxUSE_STREAMS && !defined(__WXWINCE__)
 641     if ( redirect )
 642     {
 643         si.dwFlags = STARTF_USESTDHANDLES;
 644
 645         si.hStdInput = pipeIn[wxPipe::Read];
 646         si.hStdOutput = pipeOut[wxPipe::Write];
 647         si.hStdError = pipeErr[wxPipe::Write];
 648
 649         // when the std IO is redirected, we don't show the (console) process
 650         // window by default, but this can be overridden by the caller by
 651         // specifying wxEXEC_NOHIDE flag
 652         if ( !(flags & wxEXEC_NOHIDE) )
 653         {
 654             si.dwFlags |= STARTF_USESHOWWINDOW;
 655             si.wShowWindow = SW_HIDE;
 656         }
 657
 658         // we must duplicate the handle to the write side of stdin pipe to make
 659         // it non inheritable: indeed, we must close the writing end of pipeIn
 660         // before launching the child process as otherwise this handle will be
 661         // inherited by the child which will never close it and so the pipe
 662         // will never be closed and the child will be left stuck in ReadFile()
 663         HANDLE pipeInWrite = pipeIn.Detach(wxPipe::Write);
 664         if ( !::DuplicateHandle
 665                 (
 666                     ::GetCurrentProcess(),
 667                     pipeInWrite,
 668                     ::GetCurrentProcess(),
 669                     &hpipeStdinWrite,
 670                     0,                      // desired access: unused here
 671                     FALSE,                  // not inherited
 672                     DUPLICATE_SAME_ACCESS   // same access as for src handle
 673                 ) )
 674         {
 675             wxLogLastError(_T("DuplicateHandle"));
 676         }
 677
 678         ::CloseHandle(pipeInWrite);
 679     }
 680 #endif // wxUSE_STREAMS
 681
 682     PROCESS_INFORMATION pi;
 683     DWORD dwFlags = CREATE_SUSPENDED;
 684 #ifndef __WXWINCE__
 685     dwFlags |= CREATE_DEFAULT_ERROR_MODE ;
 686 #endif
 687
 688     bool ok = ::CreateProcess
 689                 (
 690                  NULL,              // application name (use only cmd line)
 691                  (wxChar *)
 692                  command.c_str(),   // full command line
 693                  NULL,              // security attributes: defaults for both
 694                  NULL,              //   the process and its main thread
 695                  redirect,          // inherit handles if we use pipes
 696                  dwFlags,           // process creation flags
 697                  NULL,              // environment (use the same)
 698                  NULL,              // current directory (use the same)
 699                  &si,               // startup info (unused here)
 700                  &pi                // process info
 701                 ) != 0;
 702
 703 #if wxUSE_STREAMS && !defined(__WXWINCE__)
 704     // we can close the pipe ends used by child anyhow
 705     if ( redirect )
 706     {
 707         ::CloseHandle(pipeIn.Detach(wxPipe::Read));
 708         ::CloseHandle(pipeOut.Detach(wxPipe::Write));
 709         ::CloseHandle(pipeErr.Detach(wxPipe::Write));
 710     }
 711 #endif // wxUSE_STREAMS
 712
 713     if ( !ok )
 714     {
 715 #if wxUSE_STREAMS && !defined(__WXWINCE__)
 716         // close the other handles too
 717         if ( redirect )
 718         {
 719             ::CloseHandle(pipeOut.Detach(wxPipe::Read));
 720             ::CloseHandle(pipeErr.Detach(wxPipe::Read));
 721         }
 722 #endif // wxUSE_STREAMS
 723
 724         wxLogSysError(_("Execution of command '%s' failed"), command.c_str());
 725
 726         return flags & wxEXEC_SYNC ? -1 : 0;
 727     }
 728
 729 #if wxUSE_STREAMS && !defined(__WXWINCE__)
 730     // the input buffer bufOut is connected to stdout, this is why it is
 731     // called bufOut and not bufIn
 732     wxStreamTempInputBuffer bufOut,
 733                             bufErr;
 734
 735     if ( redirect )
 736     {
 737         // We can now initialize the wxStreams
 738         wxPipeInputStream *
 739             outStream = new wxPipeInputStream(pipeOut.Detach(wxPipe::Read));
 740         wxPipeInputStream *
 741             errStream = new wxPipeInputStream(pipeErr.Detach(wxPipe::Read));
 742         wxPipeOutputStream *
 743             inStream = new wxPipeOutputStream(hpipeStdinWrite);
 744
 745         handler->SetPipeStreams(outStream, inStream, errStream);
 746
 747         bufOut.Init(outStream);
 748         bufErr.Init(errStream);
 749     }
 750 #endif // wxUSE_STREAMS
 751
 752     // create a hidden window to receive notification about process
 753     // termination
 754     HWND hwnd = wxCreateHiddenWindow
 755                 (
 756                     &gs_classForHiddenWindow,
 757                     wxMSWEXEC_WNDCLASSNAME,
 758                     (WNDPROC)wxExecuteWindowCbk
 759                 );
 760
 761     wxASSERT_MSG( hwnd, wxT("can't create a hidden window for wxExecute") );
 762
 763     // Alloc data
 764     wxExecuteData *data = new wxExecuteData;
 765     data->hProcess    = pi.hProcess;
 766     data->dwProcessId = pi.dwProcessId;
 767     data->hWnd        = hwnd;
 768     data->state       = (flags & wxEXEC_SYNC) != 0;
 769     if ( flags & wxEXEC_SYNC )
 770     {
 771         // handler may be !NULL for capturing program output, but we don't use
 772         // it wxExecuteData struct in this case
 773         data->handler = NULL;
 774     }
 775     else
 776     {
 777         // may be NULL or not
 778         data->handler = handler;
 779     }
 780
 781     DWORD tid;
 782     HANDLE hThread = ::CreateThread(NULL,
 783                                     0,
 784                                     wxExecuteThread,
 785                                     (void *)data,
 786                                     0,
 787                                     &tid);
 788
 789     // resume process we created now - whether the thread creation succeeded or
 790     // not
 791     if ( ::ResumeThread(pi.hThread) == (DWORD)-1 )
 792     {
 793         // ignore it - what can we do?
 794         wxLogLastError(wxT("ResumeThread in wxExecute"));
 795     }
 796
 797     // close unneeded handle
 798     if ( !::CloseHandle(pi.hThread) )
 799         wxLogLastError(wxT("CloseHandle(hThread)"));
 800
 801     if ( !hThread )
 802     {
 803         wxLogLastError(wxT("CreateThread in wxExecute"));
 804
 805         DestroyWindow(hwnd);
 806         delete data;
 807
 808         // the process still started up successfully...
 809         return pi.dwProcessId;
 810     }
 811
 812     ::CloseHandle(hThread);
 813
 814 #if wxUSE_IPC && !defined(__WXWINCE__)
 815     // second part of DDE hack: now establish the DDE conversation with the
 816     // just launched process
 817     if ( !ddeServer.empty() )
 818     {
 819         bool ok;
 820
 821         // give the process the time to init itself
 822         //
 823         // we use a very big timeout hoping that WaitForInputIdle() will return
 824         // much sooner, but not INFINITE just in case the process hangs
 825         // completely - like this we will regain control sooner or later
 826         switch ( ::WaitForInputIdle(pi.hProcess, 10000 /* 10 seconds */) )
 827         {
 828             default:
 829                 wxFAIL_MSG( _T("unexpected WaitForInputIdle() return code") );
 830                 // fall through
 831
 832             case -1:
 833                 wxLogLastError(_T("WaitForInputIdle() in wxExecute"));
 834
 835             case WAIT_TIMEOUT:
 836                 wxLogDebug(_T("Timeout too small in WaitForInputIdle"));
 837
 838                 ok = FALSE;
 839                 break;
 840
 841             case 0:
 842                 // ok, process ready to accept DDE requests
 843                 ok = wxExecuteDDE(ddeServer, ddeTopic, ddeCommand);
 844         }
 845
 846         if ( !ok )
 847         {
 848             wxLogDebug(_T("Failed to send DDE request to the process \"%s\"."),
 849                        cmd.c_str());
 850         }
 851     }
 852 #endif // wxUSE_IPC
 853
 854     if ( !(flags & wxEXEC_SYNC) )
 855     {
 856         // clean up will be done when the process terminates
 857
 858         // return the pid
 859         return pi.dwProcessId;
 860     }
 861
 862     wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() : NULL;
 863     wxCHECK_MSG( traits, -1, _T("no wxAppTraits in wxExecute()?") );
 864
 865     // disable all app windows while waiting for the child process to finish
 866     void *cookie = traits->BeforeChildWaitLoop();
 867
 868     // wait until the child process terminates
 869     while ( data->state )
 870     {
 871 #if wxUSE_STREAMS && !defined(__WXWINCE__)
 872         bufOut.Update();
 873         bufErr.Update();
 874 #endif // wxUSE_STREAMS
 875
 876         // don't eat 100% of the CPU -- ugly but anything else requires
 877         // real async IO which we don't have for the moment
 878         ::Sleep(50);
 879
 880         // we must process messages or we'd never get wxWM_PROC_TERMINATED
 881         traits->AlwaysYield();
 882     }
 883
 884     traits->AfterChildWaitLoop(cookie);
 885
 886     DWORD dwExitCode = data->dwExitCode;
 887     delete data;
 888
 889     // return the exit code
 890     return dwExitCode;
 891 }
 892
 893 long wxExecute(wxChar **argv, int flags, wxProcess *handler)
 894 {
 895     wxString command;
 896
 897     for ( ;; )
 898     {
 899         command += *argv++;
 900         if ( !*argv )
 901             break;
 902
 903         command += _T(' ');
 904     }
 905
 906     return wxExecute(command, flags, handler);
 907 }
 908