attempt to fix race condition between Delete() and Wait()

[wxWidgets.git] / src / msw / utils.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        msw/utils.cpp
// Purpose:     Various utilities
// Author:      Julian Smart
// Modified by:
// Created:     04/01/98
// RCS-ID:      $Id$
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#ifndef WX_PRECOMP
    #include "wx/utils.h"
    #include "wx/app.h"
    #include "wx/intl.h"
    #include "wx/log.h"
#endif  //WX_PRECOMP

#include "wx/apptrait.h"
#include "wx/dynload.h"

#include "wx/msw/private.h"     // includes <windows.h>
#include "wx/msw/missing.h"     // CHARSET_HANGUL

#if defined(__GNUWIN32_OLD__) || defined(__WXWINCE__) \
    || defined(__CYGWIN32__)
    // apparently we need to include winsock.h to get WSADATA and other stuff
    // used in wxGetFullHostName() with the old mingw32 versions
    #include <winsock.h>
#endif

#include "wx/timer.h"

#if !defined(__GNUWIN32__) && !defined(__SALFORDC__) && !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
    #include <direct.h>

    #ifndef __MWERKS__
        #include <dos.h>
    #endif
#endif  //GNUWIN32

#if defined(__CYGWIN__)
    #include <sys/unistd.h>
    #include <sys/stat.h>
    #include <sys/cygwin.h> // for cygwin_conv_to_full_win32_path()
#endif  //GNUWIN32

#ifdef __BORLANDC__ // Please someone tell me which version of Borland needs
                    // this (3.1 I believe) and how to test for it.
                    // If this works for Borland 4.0 as well, then no worries.
    #include <dir.h>
#endif

// VZ: there is some code using NetXXX() functions to get the full user name:
//     I don't think it's a good idea because they don't work under Win95 and
//     seem to return the same as wxGetUserId() under NT. If you really want
//     to use them, just #define USE_NET_API
#undef USE_NET_API

#ifdef USE_NET_API
    #include <lm.h>
#endif // USE_NET_API

#if defined(__WIN32__) && !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
    #ifndef __UNIX__
        #include <io.h>
    #endif

    #ifndef __GNUWIN32__
        #include <shellapi.h>
    #endif
#endif

#ifndef __WATCOMC__
    #if !(defined(_MSC_VER) && (_MSC_VER > 800))
        #include <errno.h>
    #endif
#endif

// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------

// In the WIN.INI file
static const wxChar WX_SECTION[] = wxT("wxWindows");
static const wxChar eUSERNAME[]  = wxT("UserName");

// these are only used under Win16
#if !defined(__WIN32__) && !defined(__WXMICROWIN__)
static const wxChar eHOSTNAME[]  = wxT("HostName");
static const wxChar eUSERID[]    = wxT("UserId");
#endif // !Win32

// ============================================================================
// implementation
// ============================================================================

// ----------------------------------------------------------------------------
// get host name and related
// ----------------------------------------------------------------------------

// Get hostname only (without domain name)
bool wxGetHostName(wxChar *buf, int maxSize)
{
#if defined(__WXWINCE__)
    return FALSE;
#elif defined(__WIN32__) && !defined(__WXMICROWIN__)
    DWORD nSize = maxSize;
    if ( !::GetComputerName(buf, &nSize) )
    {
        wxLogLastError(wxT("GetComputerName"));

        return FALSE;
    }

    return TRUE;
#else
    wxChar *sysname;
    const wxChar *default_host = wxT("noname");

    if ((sysname = wxGetenv(wxT("SYSTEM_NAME"))) == NULL) {
        GetProfileString(WX_SECTION, eHOSTNAME, default_host, buf, maxSize - 1);
    } else
        wxStrncpy(buf, sysname, maxSize - 1);
    buf[maxSize] = wxT('\0');
    return *buf ? TRUE : FALSE;
#endif
}

// get full hostname (with domain name if possible)
bool wxGetFullHostName(wxChar *buf, int maxSize)
{
#if !defined( __WXMICROWIN__) && wxUSE_DYNAMIC_LOADER
    // TODO should use GetComputerNameEx() when available

    // we don't want to always link with Winsock DLL as we might not use it at
    // all, so load it dynamically here if needed
    wxDynamicLibrary dllWinsock(_T("ws2_32.dll"), wxDL_VERBATIM);
    if ( dllWinsock.IsLoaded() )
    {
        typedef int (PASCAL *WSAStartup_t)(WORD, WSADATA *);
        typedef int (PASCAL *gethostname_t)(char *, int);
        typedef hostent* (PASCAL *gethostbyname_t)(const char *);
        typedef hostent* (PASCAL *gethostbyaddr_t)(const char *, int , int);
        typedef int (PASCAL *WSACleanup_t)(void);

        #define LOAD_WINSOCK_FUNC(func)                                       \
            func ## _t                                                        \
                pfn ## func = (func ## _t)dllWinsock.GetSymbol(_T(#func))

        LOAD_WINSOCK_FUNC(WSAStartup);

        WSADATA wsa;
        if ( pfnWSAStartup && pfnWSAStartup(MAKEWORD(1, 1), &wsa) == 0 )
        {
            LOAD_WINSOCK_FUNC(gethostname);

            wxString host;
            if ( pfngethostname )
            {
                char bufA[256];
                if ( pfngethostname(bufA, WXSIZEOF(bufA)) == 0 )
                {
                    // gethostname() won't usually include the DNS domain name,
                    // for this we need to work a bit more
                    if ( !strchr(bufA, '.') )
                    {
                        LOAD_WINSOCK_FUNC(gethostbyname);

                        struct hostent *pHostEnt = pfngethostbyname
                                                    ? pfngethostbyname(bufA)
                                                    : NULL;

                        if ( pHostEnt )
                        {
                            // Windows will use DNS internally now
                            LOAD_WINSOCK_FUNC(gethostbyaddr);

                            pHostEnt = pfngethostbyaddr
                                        ? pfngethostbyaddr(pHostEnt->h_addr,
                                                           4, AF_INET)
                                        : NULL;
                        }

                        if ( pHostEnt )
                        {
                            host = wxString::FromAscii(pHostEnt->h_name);
                        }
                    }
                }
            }

            LOAD_WINSOCK_FUNC(WSACleanup);
            if ( pfnWSACleanup )
                pfnWSACleanup();


            if ( !host.empty() )
            {
                wxStrncpy(buf, host, maxSize);

                return TRUE;
            }
        }
    }
#endif // !__WXMICROWIN__

    return wxGetHostName(buf, maxSize);
}

// Get user ID e.g. jacs
bool wxGetUserId(wxChar *buf, int maxSize)
{
#if defined(__WXWINCE__)
    return FALSE;
#elif defined(__WIN32__) && !defined(__win32s__) && !defined(__WXMICROWIN__)
    DWORD nSize = maxSize;
    if ( ::GetUserName(buf, &nSize) == 0 )
    {
        // actually, it does happen on Win9x if the user didn't log on
        DWORD res = ::GetEnvironmentVariable(wxT("username"), buf, maxSize);
        if ( res == 0 )
        {
            // not found
            return FALSE;
        }
    }

    return TRUE;
#else   // Win16 or Win32s
    wxChar *user;
    const wxChar *default_id = wxT("anonymous");

    // Can't assume we have NIS (PC-NFS) or some other ID daemon
    // So we ...
    if (  (user = wxGetenv(wxT("USER"))) == NULL &&
            (user = wxGetenv(wxT("LOGNAME"))) == NULL )
    {
        // Use wxWindows configuration data (comming soon)
        GetProfileString(WX_SECTION, eUSERID, default_id, buf, maxSize - 1);
    }
    else
    {
        wxStrncpy(buf, user, maxSize - 1);
    }

    return *buf ? TRUE : FALSE;
#endif
}

// Get user name e.g. Julian Smart
bool wxGetUserName(wxChar *buf, int maxSize)
{
#if defined(__WXWINCE__)
    return FALSE;
#elif defined(USE_NET_API)
    CHAR szUserName[256];
    if ( !wxGetUserId(szUserName, WXSIZEOF(szUserName)) )
        return FALSE;

    // TODO how to get the domain name?
    CHAR *szDomain = "";

    // the code is based on the MSDN example (also see KB article Q119670)
    WCHAR wszUserName[256];          // Unicode user name
    WCHAR wszDomain[256];
    LPBYTE ComputerName;

    USER_INFO_2 *ui2;         // User structure

    // Convert ANSI user name and domain to Unicode
    MultiByteToWideChar( CP_ACP, 0, szUserName, strlen(szUserName)+1,
            wszUserName, WXSIZEOF(wszUserName) );
    MultiByteToWideChar( CP_ACP, 0, szDomain, strlen(szDomain)+1,
            wszDomain, WXSIZEOF(wszDomain) );

    // Get the computer name of a DC for the domain.
    if ( NetGetDCName( NULL, wszDomain, &ComputerName ) != NERR_Success )
    {
        wxLogError(wxT("Can not find domain controller"));

        goto error;
    }

    // Look up the user on the DC
    NET_API_STATUS status = NetUserGetInfo( (LPWSTR)ComputerName,
            (LPWSTR)&wszUserName,
            2, // level - we want USER_INFO_2
            (LPBYTE *) &ui2 );
    switch ( status )
    {
        case NERR_Success:
            // ok
            break;

        case NERR_InvalidComputer:
            wxLogError(wxT("Invalid domain controller name."));

            goto error;

        case NERR_UserNotFound:
            wxLogError(wxT("Invalid user name '%s'."), szUserName);

            goto error;

        default:
            wxLogSysError(wxT("Can't get information about user"));

            goto error;
    }

    // Convert the Unicode full name to ANSI
    WideCharToMultiByte( CP_ACP, 0, ui2->usri2_full_name, -1,
            buf, maxSize, NULL, NULL );

    return TRUE;

error:
    wxLogError(wxT("Couldn't look up full user name."));

    return FALSE;
#else  // !USE_NET_API
    // Could use NIS, MS-Mail or other site specific programs
    // Use wxWindows configuration data
    bool ok = GetProfileString(WX_SECTION, eUSERNAME, wxEmptyString, buf, maxSize - 1) != 0;
    if ( !ok )
    {
        ok = wxGetUserId(buf, maxSize);
    }

    if ( !ok )
    {
        wxStrncpy(buf, wxT("Unknown User"), maxSize);
    }
#endif // Win32/16

    return TRUE;
}

const wxChar* wxGetHomeDir(wxString *pstr)
{
  wxString& strDir = *pstr;

#if defined(__UNIX__)
    const wxChar *szHome = wxGetenv("HOME");
    if ( szHome == NULL ) {
      // we're homeless...
      wxLogWarning(_("can't find user's HOME, using current directory."));
      strDir = wxT(".");
    }
    else
       strDir = szHome;

    // add a trailing slash if needed
    if ( strDir.Last() != wxT('/') )
      strDir << wxT('/');

    #ifdef __CYGWIN__
      // Cygwin returns unix type path but that does not work well
      static wxChar windowsPath[MAX_PATH];
      cygwin_conv_to_full_win32_path(strDir, windowsPath);
      strDir = windowsPath;
    #endif
#elif defined(__WXWINCE__)
      // Nothing
#else
    #ifdef  __WIN32__
      strDir.clear();

      // If we have a valid HOME directory, as is used on many machines that
      // have unix utilities on them, we should use that.
      const wxChar *szHome = wxGetenv(wxT("HOME"));

      if ( szHome != NULL )
      {
        strDir = szHome;
      }
      else // no HOME, try HOMEDRIVE/PATH
      {
          szHome = wxGetenv(wxT("HOMEDRIVE"));
          if ( szHome != NULL )
            strDir << szHome;
          szHome = wxGetenv(wxT("HOMEPATH"));

          if ( szHome != NULL )
          {
            strDir << szHome;

            // the idea is that under NT these variables have default values
            // of "%systemdrive%:" and "\\". As we don't want to create our
            // config files in the root directory of the system drive, we will
            // create it in our program's dir. However, if the user took care
            // to set HOMEPATH to something other than "\\", we suppose that he
            // knows what he is doing and use the supplied value.
            if ( wxStrcmp(szHome, wxT("\\")) == 0 )
              strDir.clear();
          }
      }

      if ( strDir.empty() )
      {
          // If we have a valid USERPROFILE directory, as is the case in
          // Windows NT, 2000 and XP, we should use that as our home directory.
          szHome = wxGetenv(wxT("USERPROFILE"));

          if ( szHome != NULL )
            strDir = szHome;
      }

      if ( !strDir.empty() )
      {
          return strDir.c_str();
      }
      //else: fall back to the prograrm directory
    #else   // Win16
      // Win16 has no idea about home, so use the executable directory instead
    #endif  // WIN16/32

    // 260 was taken from windef.h
    #ifndef MAX_PATH
      #define MAX_PATH  260
    #endif

    wxString strPath;
    ::GetModuleFileName(::GetModuleHandle(NULL),
                        wxStringBuffer(strPath, MAX_PATH), MAX_PATH);

    // extract the dir name
    wxSplitPath(strPath, &strDir, NULL, NULL);

#endif  // UNIX/Win

  return strDir.c_str();
}

wxChar *wxGetUserHome(const wxString& WXUNUSED(user))
{
    // VZ: the old code here never worked for user != "" anyhow! Moreover, it
    //     returned sometimes a malloc()'d pointer, sometimes a pointer to a
    //     static buffer and sometimes I don't even know what.
    static wxString s_home;

    return (wxChar *)wxGetHomeDir(&s_home);
}

bool wxDirExists(const wxString& dir)
{
#ifdef __WXMICROWIN__
    return wxPathExist(dir);
#elif defined(__WIN32__)
    DWORD attribs = GetFileAttributes(dir);
    return ((attribs != (DWORD)-1) && (attribs & FILE_ATTRIBUTE_DIRECTORY));
#else // Win16
    #ifdef __BORLANDC__
        struct ffblk fileInfo;
    #else
        struct find_t fileInfo;
    #endif
    // In Borland findfirst has a different argument
    // ordering from _dos_findfirst. But _dos_findfirst
    // _should_ be ok in both MS and Borland... why not?
    #ifdef __BORLANDC__
        return (findfirst(dir, &fileInfo, _A_SUBDIR) == 0 &&
               (fileInfo.ff_attrib & _A_SUBDIR) != 0);
    #else
        return (_dos_findfirst(dir, _A_SUBDIR, &fileInfo) == 0) &&
               ((fileInfo.attrib & _A_SUBDIR) != 0);
    #endif
#endif // Win32/16
}

bool wxGetDiskSpace(const wxString& path, wxLongLong *pTotal, wxLongLong *pFree)
{
#ifdef __WXWINCE__
    return FALSE;
#else
    if ( path.empty() )
        return FALSE;

// old w32api don't have ULARGE_INTEGER
#if defined(__WIN32__) && \
    (!defined(__GNUWIN32__) || wxCHECK_W32API_VERSION( 0, 3 ))
    // GetDiskFreeSpaceEx() is not available under original Win95, check for
    // it
    typedef BOOL (WINAPI *GetDiskFreeSpaceEx_t)(LPCTSTR,
                                                PULARGE_INTEGER,
                                                PULARGE_INTEGER,
                                                PULARGE_INTEGER);

    GetDiskFreeSpaceEx_t
        pGetDiskFreeSpaceEx = (GetDiskFreeSpaceEx_t)::GetProcAddress
                              (
                                ::GetModuleHandle(_T("kernel32.dll")),
#if wxUSE_UNICODE
                                "GetDiskFreeSpaceExW"
#else
                                "GetDiskFreeSpaceExA"
#endif
                              );

    if ( pGetDiskFreeSpaceEx )
    {
        ULARGE_INTEGER bytesFree, bytesTotal;

        // may pass the path as is, GetDiskFreeSpaceEx() is smart enough
        if ( !pGetDiskFreeSpaceEx(path,
                                  &bytesFree,
                                  &bytesTotal,
                                  NULL) )
        {
            wxLogLastError(_T("GetDiskFreeSpaceEx"));

            return FALSE;
        }

        // ULARGE_INTEGER is a union of a 64 bit value and a struct containing
        // two 32 bit fields which may be or may be not named - try to make it
        // compile in all cases
#if defined(__BORLANDC__) && !defined(_ANONYMOUS_STRUCT)
        #define UL(ul) ul.u
#else // anon union
        #define UL(ul) ul
#endif
        if ( pTotal )
        {
            *pTotal = wxLongLong(UL(bytesTotal).HighPart, UL(bytesTotal).LowPart);
        }

        if ( pFree )
        {
            *pFree = wxLongLong(UL(bytesFree).HighPart, UL(bytesFree).LowPart);
        }
    }
    else
#endif // Win32
    {
        // there's a problem with drives larger than 2GB, GetDiskFreeSpaceEx()
        // should be used instead - but if it's not available, fall back on
        // GetDiskFreeSpace() nevertheless...

        DWORD lSectorsPerCluster,
              lBytesPerSector,
              lNumberOfFreeClusters,
              lTotalNumberOfClusters;

        // FIXME: this is wrong, we should extract the root drive from path
        //        instead, but this is the job for wxFileName...
        if ( !::GetDiskFreeSpace(path,
                                 &lSectorsPerCluster,
                                 &lBytesPerSector,
                                 &lNumberOfFreeClusters,
                                 &lTotalNumberOfClusters) )
        {
            wxLogLastError(_T("GetDiskFreeSpace"));

            return FALSE;
        }

        wxLongLong lBytesPerCluster = lSectorsPerCluster;
        lBytesPerCluster *= lBytesPerSector;

        if ( pTotal )
        {
            *pTotal = lBytesPerCluster;
            *pTotal *= lTotalNumberOfClusters;
        }

        if ( pFree )
        {
            *pFree = lBytesPerCluster;
            *pFree *= lNumberOfFreeClusters;
        }
    }

    return TRUE;
#endif
    // __WXWINCE__
}

// ----------------------------------------------------------------------------
// env vars
// ----------------------------------------------------------------------------

bool wxGetEnv(const wxString& var, wxString *value)
{
#ifdef __WXWINCE__
    return FALSE;
#elif defined(__WIN16__)
    const wxChar* ret = wxGetenv(var);
    if ( !ret )
        return FALSE;

    if ( value )
    {
        *value = ret;
    }

    return TRUE;
#else // Win32
    // first get the size of the buffer
    DWORD dwRet = ::GetEnvironmentVariable(var, NULL, 0);
    if ( !dwRet )
    {
        // this means that there is no such variable
        return FALSE;
    }

    if ( value )
    {
        (void)::GetEnvironmentVariable(var, wxStringBuffer(*value, dwRet),
                                       dwRet);
    }

    return TRUE;
#endif // Win16/32
}

bool wxSetEnv(const wxString& var, const wxChar *value)
{
    // some compilers have putenv() or _putenv() or _wputenv() but it's better
    // to always use Win32 function directly instead of dealing with them
#if defined(__WIN32__) && !defined(__WXWINCE__)
    if ( !::SetEnvironmentVariable(var, value) )
    {
        wxLogLastError(_T("SetEnvironmentVariable"));

        return FALSE;
    }

    return TRUE;
#else // no way to set env vars
    return FALSE;
#endif
}

// ----------------------------------------------------------------------------
// process management
// ----------------------------------------------------------------------------

// structure used to pass parameters from wxKill() to wxEnumFindByPidProc()
struct wxFindByPidParams
{
    wxFindByPidParams() { hwnd = 0; pid = 0; }

    // the HWND used to return the result
    HWND hwnd;

    // the PID we're looking from
    DWORD pid;

    DECLARE_NO_COPY_CLASS(wxFindByPidParams)
};

// wxKill helper: EnumWindows() callback which is used to find the first (top
// level) window belonging to the given process
BOOL CALLBACK wxEnumFindByPidProc(HWND hwnd, LPARAM lParam)
{
    DWORD pid;
    (void)::GetWindowThreadProcessId(hwnd, &pid);

    wxFindByPidParams *params = (wxFindByPidParams *)lParam;
    if ( pid == params->pid )
    {
        // remember the window we found
        params->hwnd = hwnd;

        // return FALSE to stop the enumeration
        return FALSE;
    }

    // continue enumeration
    return TRUE;
}

int wxKill(long pid, wxSignal sig, wxKillError *krc)
{
    // get the process handle to operate on
    HANDLE hProcess = ::OpenProcess(SYNCHRONIZE |
                                    PROCESS_TERMINATE |
                                    PROCESS_QUERY_INFORMATION,
                                    FALSE, // not inheritable
                                    (DWORD)pid);
    if ( hProcess == NULL )
    {
        if ( krc )
        {
            if ( ::GetLastError() == ERROR_ACCESS_DENIED )
            {
                *krc = wxKILL_ACCESS_DENIED;
            }
            else
            {
                *krc = wxKILL_NO_PROCESS;
            }
        }

        return -1;
    }

    bool ok = TRUE;
    switch ( sig )
    {
        case wxSIGKILL:
            // kill the process forcefully returning -1 as error code
            if ( !::TerminateProcess(hProcess, (UINT)-1) )
            {
                wxLogSysError(_("Failed to kill process %d"), pid);

                if ( krc )
                {
                    // this is not supposed to happen if we could open the
                    // process
                    *krc = wxKILL_ERROR;
                }

                ok = FALSE;
            }
            break;

        case wxSIGNONE:
            // do nothing, we just want to test for process existence
            break;

        default:
            // any other signal means "terminate"
            {
                wxFindByPidParams params;
                params.pid = (DWORD)pid;

                // EnumWindows() has nice semantics: it returns 0 if it found
                // something or if an error occured and non zero if it
                // enumerated all the window
                if ( !::EnumWindows(wxEnumFindByPidProc, (LPARAM)&params) )
                {
                    // did we find any window?
                    if ( params.hwnd )
                    {
                        // tell the app to close
                        //
                        // NB: this is the harshest way, the app won't have
                        //     opportunity to save any files, for example, but
                        //     this is probably what we want here. If not we
                        //     can also use SendMesageTimeout(WM_CLOSE)
                        if ( !::PostMessage(params.hwnd, WM_QUIT, 0, 0) )
                        {
                            wxLogLastError(_T("PostMessage(WM_QUIT)"));
                        }
                    }
                    else // it was an error then
                    {
                        wxLogLastError(_T("EnumWindows"));

                        ok = FALSE;
                    }
                }
                else // no windows for this PID
                {
                    if ( krc )
                    {
                        *krc = wxKILL_ERROR;
                    }

                    ok = FALSE;
                }
            }
    }

    // the return code
    DWORD rc;

    if ( ok )
    {
        // as we wait for a short time, we can use just WaitForSingleObject()
        // and not MsgWaitForMultipleObjects()
        switch ( ::WaitForSingleObject(hProcess, 500 /* msec */) )
        {
            case WAIT_OBJECT_0:
                // process terminated
                if ( !::GetExitCodeProcess(hProcess, &rc) )
                {
                    wxLogLastError(_T("GetExitCodeProcess"));
                }
                break;

            default:
                wxFAIL_MSG( _T("unexpected WaitForSingleObject() return") );
                // fall through

            case WAIT_FAILED:
                wxLogLastError(_T("WaitForSingleObject"));
                // fall through

            case WAIT_TIMEOUT:
                if ( krc )
                {
                    *krc = wxKILL_ERROR;
                }

                rc = STILL_ACTIVE;
                break;
        }
    }
    else // !ok
    {
        // just to suppress the warnings about uninitialized variable
        rc = 0;
    }

    ::CloseHandle(hProcess);

    // the return code is the same as from Unix kill(): 0 if killed
    // successfully or -1 on error
    //
    // be careful to interpret rc correctly: for wxSIGNONE we return success if
    // the process exists, for all the other sig values -- if it doesn't
    if ( ok &&
            ((sig == wxSIGNONE) == (rc == STILL_ACTIVE)) )
    {
        if ( krc )
        {
            *krc = wxKILL_OK;
        }

        return 0;
    }

    // error
    return -1;
}

// Execute a program in an Interactive Shell
bool wxShell(const wxString& command)
{
#ifdef __WXWINCE__
    return FALSE;
#else
    wxChar *shell = wxGetenv(wxT("COMSPEC"));
    if ( !shell )
        shell = (wxChar*) wxT("\\COMMAND.COM");

    wxString cmd;
    if ( !command )
    {
        // just the shell
        cmd = shell;
    }
    else
    {
        // pass the command to execute to the command processor
        cmd.Printf(wxT("%s /c %s"), shell, command.c_str());
    }

    return wxExecute(cmd, wxEXEC_SYNC) == 0;
#endif
}

// Shutdown or reboot the PC
bool wxShutdown(wxShutdownFlags wFlags)
{
#ifdef __WXWINCE__
    return FALSE;
#elif defined(__WIN32__)
    bool bOK = TRUE;

    if ( wxGetOsVersion(NULL, NULL) == wxWINDOWS_NT ) // if is NT or 2K
    {
        // Get a token for this process.
        HANDLE hToken;
        bOK = ::OpenProcessToken(GetCurrentProcess(),
                                 TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY,
                                 &hToken) != 0;
        if ( bOK )
        {
            TOKEN_PRIVILEGES tkp;

            // Get the LUID for the shutdown privilege.
            ::LookupPrivilegeValue(NULL, SE_SHUTDOWN_NAME,
                                   &tkp.Privileges[0].Luid);

            tkp.PrivilegeCount = 1;  // one privilege to set
            tkp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;

            // Get the shutdown privilege for this process.
            ::AdjustTokenPrivileges(hToken, FALSE, &tkp, 0,
                                    (PTOKEN_PRIVILEGES)NULL, 0);

            // Cannot test the return value of AdjustTokenPrivileges.
            bOK = ::GetLastError() == ERROR_SUCCESS;
        }
    }

    if ( bOK )
    {
        UINT flags = EWX_SHUTDOWN | EWX_FORCE;
        switch ( wFlags )
        {
            case wxSHUTDOWN_POWEROFF:
                flags |= EWX_POWEROFF;
                break;

            case wxSHUTDOWN_REBOOT:
                flags |= EWX_REBOOT;
                break;

            default:
                wxFAIL_MSG( _T("unknown wxShutdown() flag") );
                return FALSE;
        }

        bOK = ::ExitWindowsEx(EWX_SHUTDOWN | EWX_FORCE | EWX_REBOOT, 0) != 0;
    }

    return bOK;
#else // Win16
    return FALSE;
#endif // Win32/16
}

// ----------------------------------------------------------------------------
// misc
// ----------------------------------------------------------------------------

// Get free memory in bytes, or -1 if cannot determine amount (e.g. on UNIX)
long wxGetFreeMemory()
{
#if defined(__WIN32__) && !defined(__BORLANDC__)
    MEMORYSTATUS memStatus;
    memStatus.dwLength = sizeof(MEMORYSTATUS);
    GlobalMemoryStatus(&memStatus);
    return memStatus.dwAvailPhys;
#else
    return (long)GetFreeSpace(0);
#endif
}

unsigned long wxGetProcessId()
{
#ifdef __WIN32__
    return ::GetCurrentProcessId();
#else
    return 0;
#endif
}

// Emit a beeeeeep
void wxBell()
{
    ::MessageBeep((UINT)-1);        // default sound
}

wxString wxGetOsDescription()
{
#ifdef __WIN32__
    wxString str;

    OSVERSIONINFO info;
    wxZeroMemory(info);

    info.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
    if ( ::GetVersionEx(&info) )
    {
        switch ( info.dwPlatformId )
        {
            case VER_PLATFORM_WIN32s:
                str = _("Win32s on Windows 3.1");
                break;

            case VER_PLATFORM_WIN32_WINDOWS:
                str.Printf(_("Windows 9%c"),
                           info.dwMinorVersion == 0 ? _T('5') : _T('8'));
                if ( !wxIsEmpty(info.szCSDVersion) )
                {
                    str << _T(" (") << info.szCSDVersion << _T(')');
                }
                break;

            case VER_PLATFORM_WIN32_NT:
                str.Printf(_T("Windows NT %lu.%lu (build %lu"),
                           info.dwMajorVersion,
                           info.dwMinorVersion,
                           info.dwBuildNumber);
                if ( !wxIsEmpty(info.szCSDVersion) )
                {
                    str << _T(", ") << info.szCSDVersion;
                }
                str << _T(')');
                break;
        }
    }
    else
    {
        wxFAIL_MSG( _T("GetVersionEx() failed") ); // should never happen
    }

    return str;
#else // Win16
    return _("Windows 3.1");
#endif // Win32/16
}

wxToolkitInfo& wxAppTraits::GetToolkitInfo()
{
    // cache the version info, it's not going to change
    //
    // NB: this is MT-safe, we may use these static vars from different threads
    //     but as they always have the same value it doesn't matter
    static int s_ver = -1,
               s_major = -1,
               s_minor = -1;

    if ( s_ver == -1 )
    {
        OSVERSIONINFO info;
        wxZeroMemory(info);

        s_ver = wxWINDOWS;
        info.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
        if ( ::GetVersionEx(&info) )
        {
            s_major = info.dwMajorVersion;
            s_minor = info.dwMinorVersion;

            switch ( info.dwPlatformId )
            {
                case VER_PLATFORM_WIN32s:
                    s_ver = wxWIN32S;
                    break;

                case VER_PLATFORM_WIN32_WINDOWS:
                    s_ver = wxWIN95;
                    break;

                case VER_PLATFORM_WIN32_NT:
                    s_ver = wxWINDOWS_NT;
                    break;
#ifdef __WXWINCE__
                case VER_PLATFORM_WIN32_CE:
                    s_ver = wxWINDOWS_CE;
                    break;
#endif                    
            }
        }
    }

    static wxToolkitInfo info;    
    info.versionMajor = s_major;
    info.versionMinor = s_minor;
    info.os = s_ver;
    info.name = _T("wxBase");
    return info;
}

// ----------------------------------------------------------------------------
// sleep functions
// ----------------------------------------------------------------------------

void wxUsleep(unsigned long milliseconds)
{
    ::Sleep(milliseconds);
}

void wxSleep(int nSecs)
{
    wxUsleep(1000*nSecs);
}

// ----------------------------------------------------------------------------
// font encoding <-> Win32 codepage conversion functions
// ----------------------------------------------------------------------------

extern WXDLLIMPEXP_BASE long wxEncodingToCharset(wxFontEncoding encoding)
{
    switch ( encoding )
    {
        // although this function is supposed to return an exact match, do do
        // some mappings here for the most common case of "standard" encoding
        case wxFONTENCODING_SYSTEM:
            return DEFAULT_CHARSET;

        case wxFONTENCODING_ISO8859_1:
        case wxFONTENCODING_ISO8859_15:
        case wxFONTENCODING_CP1252:
            return ANSI_CHARSET;

#if !defined(__WXMICROWIN__)
        // The following four fonts are multi-byte charsets
        case wxFONTENCODING_CP932:
            return SHIFTJIS_CHARSET;

        case wxFONTENCODING_CP936:
            return GB2312_CHARSET;

        case wxFONTENCODING_CP949:
            return HANGUL_CHARSET;

        case wxFONTENCODING_CP950:
            return CHINESEBIG5_CHARSET;

        // The rest are single byte encodings
        case wxFONTENCODING_CP1250:
            return EASTEUROPE_CHARSET;

        case wxFONTENCODING_CP1251:
            return RUSSIAN_CHARSET;

        case wxFONTENCODING_CP1253:
            return GREEK_CHARSET;

        case wxFONTENCODING_CP1254:
            return TURKISH_CHARSET;

        case wxFONTENCODING_CP1255:
            return HEBREW_CHARSET;

        case wxFONTENCODING_CP1256:
            return ARABIC_CHARSET;

        case wxFONTENCODING_CP1257:
            return BALTIC_CHARSET;

        case wxFONTENCODING_CP874:
            return THAI_CHARSET;
#endif // !__WXMICROWIN__

        case wxFONTENCODING_CP437:
            return OEM_CHARSET;

        default:
            // no way to translate this encoding into a Windows charset
            return -1;
    }
}

// we have 2 versions of wxCharsetToCodepage(): the old one which directly
// looks up the vlaues in the registry and the new one which is more
// politically correct and has more chances to work on other Windows versions
// as well but the old version is still needed for !wxUSE_FONTMAP case
#if wxUSE_FONTMAP

#include "wx/fontmap.h"

extern WXDLLIMPEXP_BASE long wxEncodingToCodepage(wxFontEncoding encoding)
{
    // translate encoding into the Windows CHARSET
    long charset = wxEncodingToCharset(encoding);
    if ( charset == -1 )
        return -1;

    // translate CHARSET to code page
    CHARSETINFO csetInfo;
    if ( !::TranslateCharsetInfo((DWORD *)(DWORD)charset,
                                 &csetInfo,
                                 TCI_SRCCHARSET) )
    {
        wxLogLastError(_T("TranslateCharsetInfo(TCI_SRCCHARSET)"));

        return -1;
    }

    return csetInfo.ciACP;
}

extern long wxCharsetToCodepage(const wxChar *name)
{
    // first get the font encoding for this charset
    if ( !name )
        return -1;

    wxFontEncoding enc = wxFontMapper::Get()->CharsetToEncoding(name, FALSE);
    if ( enc == wxFONTENCODING_SYSTEM )
        return -1;

    // the use the helper function
    return wxEncodingToCodepage(enc);
}

#else // !wxUSE_FONTMAP

#include "wx/msw/registry.h"

// this should work if Internet Exploiter is installed
extern long wxCharsetToCodepage(const wxChar *name)
{
    if (!name)
        return GetACP();

    long CP = -1;

    wxString path(wxT("MIME\\Database\\Charset\\"));
    wxString cn(name);

    // follow the alias loop
    for ( ;; )
    {
        wxRegKey key(wxRegKey::HKCR, path + cn);

        if (!key.Exists())
            break;

        // two cases: either there's an AliasForCharset string,
        // or there are Codepage and InternetEncoding dwords.
        // The InternetEncoding gives us the actual encoding,
        // the Codepage just says which Windows character set to
        // use when displaying the data.
        if (key.HasValue(wxT("InternetEncoding")) &&
            key.QueryValue(wxT("InternetEncoding"), &CP))
            break;

        // no encoding, see if it's an alias
        if (!key.HasValue(wxT("AliasForCharset")) ||
            !key.QueryValue(wxT("AliasForCharset"), cn))
            break;
    }

    return CP;
}

#endif // wxUSE_FONTMAP/!wxUSE_FONTMAP