src/common/filename.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/filename.cpp
   3 // Purpose:     wxFileName - encapsulates a file path
   4 // Author:      Robert Roebling, Vadim Zeitlin
   5 // Modified by:
   6 // Created:     28.12.2000
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2000 Robert Roebling
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #ifdef __GNUG__
  21     #pragma implementation "filename.h"
  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/intl.h"
  33     #include "wx/log.h"
  34 #endif
  35
  36 #include "wx/filename.h"
  37 #include "wx/tokenzr.h"
  38 #include "wx/config.h"          // for wxExpandEnvVars
  39 #include "wx/utils.h"
  40
  41 #if wxUSE_DYNLIB_CLASS
  42 #include "wx/dynlib.h"
  43 #endif
  44
  45 // For GetShort/LongPathName
  46 #ifdef __WIN32__
  47 #include <windows.h>
  48 #include "wx/msw/winundef.h"
  49 #endif
  50
  51 // ============================================================================
  52 // implementation
  53 // ============================================================================
  54
  55 // ----------------------------------------------------------------------------
  56 // wxFileName construction
  57 // ----------------------------------------------------------------------------
  58
  59 void wxFileName::Assign( const wxFileName &filepath )
  60 {
  61     m_ext = filepath.GetExt();
  62     m_name = filepath.GetName();
  63     m_dirs = filepath.GetDirs();
  64 }
  65
  66 void wxFileName::Assign( const wxString& path,
  67                          const wxString& name,
  68                          const wxString& ext,
  69                          wxPathFormat format )
  70 {
  71     wxStringTokenizer tn(path, GetPathSeparators(format),
  72                          wxTOKEN_RET_EMPTY_ALL);
  73     bool first = TRUE;
  74     m_dirs.Clear();
  75     while ( tn.HasMoreTokens() )
  76     {
  77         wxString token = tn.GetNextToken();
  78
  79         // If the path starts with a slash, we need the first
  80         // dir entry to be an empty for later reassembly.
  81         if (first || !token.IsEmpty())
  82             m_dirs.Add( token );
  83
  84         first = FALSE;
  85     }
  86
  87     m_ext = ext;
  88     m_name = name;
  89 }
  90
  91 void wxFileName::Assign(const wxString& fullpath,
  92                         wxPathFormat format)
  93 {
  94     wxString path, name, ext;
  95     SplitPath(fullpath, &path, &name, &ext, format);
  96
  97     Assign(path, name, ext, format);
  98 }
  99
 100 void wxFileName::Assign(const wxString& path,
 101                         const wxString& fullname,
 102                         wxPathFormat format)
 103 {
 104     wxString name, ext;
 105     SplitPath(fullname, NULL /* no path */, &name, &ext, format);
 106
 107     Assign(path, name, ext, format);
 108 }
 109
 110 void wxFileName::Clear()
 111 {
 112     m_dirs.Clear();
 113     m_name =
 114     m_ext = wxEmptyString;
 115 }
 116
 117 /* static */
 118 wxFileName wxFileName::FileName(const wxString& file)
 119 {
 120     return wxFileName(file);
 121 }
 122
 123 /* static */
 124 wxFileName wxFileName::DirName(const wxString& dir)
 125 {
 126     wxFileName fn;
 127     fn.AssignDir(dir);
 128     return fn;
 129 }
 130
 131 // ----------------------------------------------------------------------------
 132 // existence tests
 133 // ----------------------------------------------------------------------------
 134
 135 bool wxFileName::FileExists()
 136 {
 137     return wxFileName::FileExists( GetFullPath() );
 138 }
 139
 140 bool wxFileName::FileExists( const wxString &file )
 141 {
 142     return ::wxFileExists( file );
 143 }
 144
 145 bool wxFileName::DirExists()
 146 {
 147     return wxFileName::DirExists( GetFullPath() );
 148 }
 149
 150 bool wxFileName::DirExists( const wxString &dir )
 151 {
 152     return ::wxDirExists( dir );
 153 }
 154
 155 wxDateTime wxFileName::GetModificationTime()
 156 {
 157     wxDateTime ret( wxFileModificationTime( GetFullPath() ) );
 158
 159     return ret;
 160 }
 161
 162 // ----------------------------------------------------------------------------
 163 // CWD and HOME stuff
 164 // ----------------------------------------------------------------------------
 165
 166 void wxFileName::AssignCwd()
 167 {
 168     AssignDir(wxFileName::GetCwd());
 169 }
 170
 171 /* static */
 172 wxString wxFileName::GetCwd()
 173 {
 174     return ::wxGetCwd();
 175 }
 176
 177 bool wxFileName::SetCwd()
 178 {
 179     return wxFileName::SetCwd( GetFullPath() );
 180 }
 181
 182 bool wxFileName::SetCwd( const wxString &cwd )
 183 {
 184     return ::wxSetWorkingDirectory( cwd );
 185 }
 186
 187 void wxFileName::AssignHomeDir()
 188 {
 189     AssignDir(wxFileName::GetHomeDir());
 190 }
 191
 192 wxString wxFileName::GetHomeDir()
 193 {
 194     return ::wxGetHomeDir();
 195 }
 196
 197 void wxFileName::AssignTempFileName( const wxString &prefix )
 198 {
 199     wxString fullname;
 200     if ( wxGetTempFileName(prefix, fullname) )
 201     {
 202         Assign(fullname);
 203     }
 204     else // error
 205     {
 206         Clear();
 207     }
 208 }
 209
 210 // ----------------------------------------------------------------------------
 211 // directory operations
 212 // ----------------------------------------------------------------------------
 213
 214 bool wxFileName::Mkdir( int perm, bool full )
 215 {
 216     return wxFileName::Mkdir( GetFullPath(), perm, full );
 217 }
 218
 219 bool wxFileName::Mkdir( const wxString &dir, int perm, bool full )
 220 {
 221     if (full)
 222     {
 223         wxFileName filename(dir);
 224         wxArrayString dirs = filename.GetDirs();
 225         dirs.Add(filename.GetName());
 226
 227         size_t count = dirs.GetCount();
 228         size_t i;
 229         wxString currPath;
 230         int noErrors = 0;
 231         for ( i = 0; i < count; i++ )
 232         {
 233             currPath += dirs[i];
 234
 235             if (currPath.Last() == wxT(':'))
 236             {
 237                 // Can't create a root directory so continue to next dir
 238                 currPath += wxFILE_SEP_PATH;
 239                 continue;
 240             }
 241
 242             if (!DirExists(currPath))
 243                 if (!wxMkdir(currPath, perm))
 244                     noErrors ++;
 245
 246             if ( (i < (count-1)) )
 247                 currPath += wxFILE_SEP_PATH;
 248         }
 249
 250         return (noErrors == 0);
 251
 252     }
 253     else
 254         return ::wxMkdir( dir, perm );
 255 }
 256
 257 bool wxFileName::Rmdir()
 258 {
 259     return wxFileName::Rmdir( GetFullPath() );
 260 }
 261
 262 bool wxFileName::Rmdir( const wxString &dir )
 263 {
 264     return ::wxRmdir( dir );
 265 }
 266
 267 // ----------------------------------------------------------------------------
 268 // path normalization
 269 // ----------------------------------------------------------------------------
 270
 271 bool wxFileName::Normalize(wxPathNormalize flags,
 272                            const wxString& cwd,
 273                            wxPathFormat format)
 274 {
 275     // the existing path components
 276     wxArrayString dirs = GetDirs();
 277
 278     // the path to prepend in front to make the path absolute
 279     wxFileName curDir;
 280
 281     format = GetFormat(format);
 282
 283     // make the path absolute
 284     if ( (flags & wxPATH_NORM_ABSOLUTE) && !IsAbsolute() )
 285     {
 286         if ( cwd.empty() )
 287             curDir.AssignCwd();
 288         else
 289             curDir.AssignDir(cwd);
 290     }
 291
 292     // handle ~ stuff under Unix only
 293     if ( (format == wxPATH_UNIX) && (flags & wxPATH_NORM_TILDE) )
 294     {
 295         if ( !dirs.IsEmpty() )
 296         {
 297             wxString dir = dirs[0u];
 298             if ( !dir.empty() && dir[0u] == _T('~') )
 299             {
 300                 curDir.AssignDir(wxGetUserHome(dir.c_str() + 1));
 301
 302                 dirs.RemoveAt(0u);
 303             }
 304         }
 305     }
 306
 307     if ( curDir.IsOk() )
 308     {
 309         wxArrayString dirsNew = curDir.GetDirs();
 310         size_t count = dirs.GetCount();
 311         for ( size_t n = 0; n < count; n++ )
 312         {
 313             dirsNew.Add(dirs[n]);
 314         }
 315
 316         dirs = dirsNew;
 317     }
 318
 319     // now deal with ".", ".." and the rest
 320     m_dirs.Empty();
 321     size_t count = dirs.GetCount();
 322     for ( size_t n = 0; n < count; n++ )
 323     {
 324         wxString dir = dirs[n];
 325
 326         if ( flags && wxPATH_NORM_DOTS )
 327         {
 328             if ( dir == wxT(".") )
 329             {
 330                 // just ignore
 331                 continue;
 332             }
 333
 334             if ( dir == wxT("..") )
 335             {
 336                 if ( m_dirs.IsEmpty() )
 337                 {
 338                     wxLogError(_("The path '%s' contains too many \"..\"!"),
 339                                GetFullPath().c_str());
 340                     return FALSE;
 341                 }
 342
 343                 m_dirs.Remove(m_dirs.GetCount() - 1);
 344                 continue;
 345             }
 346         }
 347
 348         if ( flags & wxPATH_NORM_ENV_VARS )
 349         {
 350             dir = wxExpandEnvVars(dir);
 351         }
 352
 353         if ( (flags & wxPATH_NORM_CASE) && !IsCaseSensitive(format) )
 354         {
 355             dir.MakeLower();
 356         }
 357
 358         m_dirs.Add(dir);
 359     }
 360
 361     if ( (flags & wxPATH_NORM_CASE) && !IsCaseSensitive(format) )
 362     {
 363         // VZ: expand env vars here too?
 364
 365         m_name.MakeLower();
 366         m_ext.MakeLower();
 367     }
 368
 369 #if defined(__WXMSW__) && defined(__WIN32__)
 370     if (flags & wxPATH_NORM_LONG)
 371     {
 372         Assign(GetLongPath());
 373     }
 374 #endif
 375
 376     return TRUE;
 377 }
 378
 379 // ----------------------------------------------------------------------------
 380 // filename kind tests
 381 // ----------------------------------------------------------------------------
 382
 383 bool wxFileName::SameAs( const wxFileName &filepath, wxPathFormat format)
 384 {
 385     wxFileName fn1 = *this,
 386                fn2 = filepath;
 387
 388     // get cwd only once - small time saving
 389     wxString cwd = wxGetCwd();
 390     fn1.Normalize(wxPATH_NORM_ALL, cwd, format);
 391     fn2.Normalize(wxPATH_NORM_ALL, cwd, format);
 392
 393     if ( fn1.GetFullPath() == fn2.GetFullPath() )
 394         return TRUE;
 395
 396     // TODO: compare inodes for Unix, this works even when filenames are
 397     //       different but files are the same (symlinks) (VZ)
 398
 399     return FALSE;
 400 }
 401
 402 /* static */
 403 bool wxFileName::IsCaseSensitive( wxPathFormat format )
 404 {
 405     // only DOS filenames are case-sensitive
 406     return GetFormat(format) != wxPATH_DOS;
 407 }
 408
 409 bool wxFileName::IsRelative( wxPathFormat format )
 410 {
 411     return !IsAbsolute(format);
 412 }
 413
 414 bool wxFileName::IsAbsolute( wxPathFormat format )
 415 {
 416     wxChar ch = m_dirs.IsEmpty() ? _T('\0') : m_dirs[0u][0u];
 417
 418     // Hack to cope with e.g. c:\thing - need something better
 419     wxChar driveSep = _T('\0');
 420     if (!m_dirs.IsEmpty() && m_dirs[0].Length() > 1)
 421         driveSep = m_dirs[0u][1u];
 422
 423     // the path is absolute if it starts with a path separator or, only for
 424     // Unix filenames, with "~" or "~user"
 425     return IsPathSeparator(ch, format) ||
 426            driveSep == _T(':') ||
 427            (GetFormat(format) == wxPATH_UNIX && ch == _T('~') );
 428 }
 429
 430 /* static */
 431 wxString wxFileName::GetPathSeparators(wxPathFormat format)
 432 {
 433     wxString seps;
 434     switch ( GetFormat(format) )
 435     {
 436         case wxPATH_DOS:
 437             // accept both as native APIs do
 438             seps << wxFILE_SEP_PATH_UNIX << wxFILE_SEP_PATH_DOS;
 439             break;
 440
 441         default:
 442             wxFAIL_MSG( _T("unknown wxPATH_XXX style") );
 443             // fall through
 444
 445         case wxPATH_UNIX:
 446             seps = wxFILE_SEP_PATH_UNIX;
 447             break;
 448
 449         case wxPATH_MAC:
 450             seps = wxFILE_SEP_PATH_MAC;
 451             break;
 452     }
 453
 454     return seps;
 455 }
 456
 457 /* static */
 458 bool wxFileName::IsPathSeparator(wxChar ch, wxPathFormat format)
 459 {
 460     return GetPathSeparators(format).Find(ch) != wxNOT_FOUND;
 461 }
 462
 463 bool wxFileName::IsWild( wxPathFormat format )
 464 {
 465     // FIXME: this is probably false for Mac and this is surely wrong for most
 466     //        of Unix shells (think about "[...]")
 467         (void)format;
 468     return m_name.find_first_of(_T("*?")) != wxString::npos;
 469 }
 470
 471 // ----------------------------------------------------------------------------
 472 // path components manipulation
 473 // ----------------------------------------------------------------------------
 474
 475 void wxFileName::AppendDir( const wxString &dir )
 476 {
 477     m_dirs.Add( dir );
 478 }
 479
 480 void wxFileName::PrependDir( const wxString &dir )
 481 {
 482     m_dirs.Insert( dir, 0 );
 483 }
 484
 485 void wxFileName::InsertDir( int before, const wxString &dir )
 486 {
 487     m_dirs.Insert( dir, before );
 488 }
 489
 490 void wxFileName::RemoveDir( int pos )
 491 {
 492     m_dirs.Remove( (size_t)pos );
 493 }
 494
 495 // ----------------------------------------------------------------------------
 496 // accessors
 497 // ----------------------------------------------------------------------------
 498
 499 void wxFileName::SetFullName(const wxString& fullname)
 500 {
 501     SplitPath(fullname, NULL /* no path */, &m_name, &m_ext);
 502 }
 503
 504 wxString wxFileName::GetFullName() const
 505 {
 506     wxString fullname = m_name;
 507     if ( !m_ext.empty() )
 508     {
 509         fullname << wxFILE_SEP_EXT << m_ext;
 510     }
 511
 512     return fullname;
 513 }
 514
 515 wxString wxFileName::GetPath( bool add_separator, wxPathFormat format ) const
 516 {
 517     format = GetFormat( format );
 518
 519     wxString ret;
 520     size_t count = m_dirs.GetCount();
 521     for ( size_t i = 0; i < count; i++ )
 522     {
 523         ret += m_dirs[i];
 524         if ( add_separator || (i < count) )
 525             ret += wxFILE_SEP_PATH;
 526     }
 527
 528     return ret;
 529 }
 530
 531 wxString wxFileName::GetFullPath( wxPathFormat format ) const
 532 {
 533     format = GetFormat( format );
 534
 535     wxString ret;
 536     if (format == wxPATH_DOS)
 537     {
 538         for (size_t i = 0; i < m_dirs.GetCount(); i++)
 539         {
 540             ret += m_dirs[i];
 541             ret += '\\';
 542         }
 543     }
 544     else
 545     if (format == wxPATH_UNIX)
 546     {
 547         for (size_t i = 0; i < m_dirs.GetCount(); i++)
 548         {
 549             ret += m_dirs[i];
 550             ret += '/';
 551         }
 552     }
 553     else
 554     {
 555         for (size_t i = 0; i < m_dirs.GetCount(); i++)
 556         {
 557             ret += m_dirs[i];
 558             ret += ':';
 559         }
 560     }
 561
 562     ret += m_name;
 563
 564     if (!m_ext.IsEmpty())
 565     {
 566         ret += '.';
 567         ret += m_ext;
 568     }
 569
 570     return ret;
 571 }
 572
 573 // Return the short form of the path (returns identity on non-Windows platforms)
 574 wxString wxFileName::GetShortPath() const
 575 {
 576 #if defined(__WXMSW__) && defined(__WIN32__) && !defined(__WXMICROWIN__)
 577     wxString path(GetFullPath());
 578     wxString pathOut;
 579     DWORD sz = ::GetShortPathName(path, NULL, 0);
 580     bool ok = sz != 0;
 581     if ( ok )
 582     {
 583         ok = ::GetShortPathName
 584                (
 585                 path,
 586                 pathOut.GetWriteBuf(sz),
 587                 sz
 588                ) != 0;
 589         pathOut.UngetWriteBuf();
 590     }
 591     if (ok)
 592         return pathOut;
 593
 594     return path;
 595 #else
 596     return GetFullPath();
 597 #endif
 598 }
 599
 600 // Return the long form of the path (returns identity on non-Windows platforms)
 601 wxString wxFileName::GetLongPath() const
 602 {
 603 #if defined(__WXMSW__) && defined(__WIN32__) && !defined(__WXMICROWIN__)
 604     wxString path(GetFullPath());
 605     wxString pathOut;
 606     bool success = FALSE;
 607
 608     // VZ: this code was disabled, why?
 609 #if 0 // wxUSE_DYNLIB_CLASS
 610     typedef DWORD (*GET_LONG_PATH_NAME)(const wxChar *, wxChar *, DWORD);
 611
 612     static bool s_triedToLoad = FALSE;
 613
 614     if ( !s_triedToLoad )
 615     {
 616         s_triedToLoad = TRUE;
 617         wxDllType dllKernel = wxDllLoader::LoadLibrary(_T("kernel32"));
 618         if ( dllKernel )
 619         {
 620             // may succeed or fail depending on the Windows version
 621                         static GET_LONG_PATH_NAME s_pfnGetLongPathName = NULL;
 622 #ifdef _UNICODE
 623             s_pfnGetLongPathName = (GET_LONG_PATH_NAME) wxDllLoader::GetSymbol(dllKernel, _T("GetLongPathNameW"));
 624 #else
 625             s_pfnGetLongPathName = (GET_LONG_PATH_NAME) wxDllLoader::GetSymbol(dllKernel, _T("GetLongPathNameA"));
 626 #endif
 627
 628             wxDllLoader::UnloadLibrary(dllKernel);
 629
 630             if ( s_pfnGetLongPathName )
 631             {
 632                 DWORD dwSize = (*s_pfnGetLongPathName)(path, NULL, 0);
 633                 bool ok = dwSize > 0;
 634
 635                 if ( ok )
 636                 {
 637                     DWORD sz = (*s_pfnGetLongPathName)(path, NULL, 0);
 638                     ok = sz != 0;
 639                     if ( ok )
 640                     {
 641                         ok = (*s_pfnGetLongPathName)
 642                                 (
 643                                 path,
 644                                 pathOut.GetWriteBuf(sz),
 645                                 sz
 646                                 ) != 0;
 647                         pathOut.UngetWriteBuf();
 648
 649                         success = TRUE;
 650                     }
 651                 }
 652             }
 653         }
 654     }
 655     if (success)
 656         return pathOut;
 657 #endif // wxUSE_DYNLIB_CLASS
 658
 659     if (!success)
 660     {
 661         // The OS didn't support GetLongPathName, or some other error.
 662         // We need to call FindFirstFile on each component in turn.
 663
 664         WIN32_FIND_DATA findFileData;
 665         HANDLE hFind;
 666         pathOut = wxEmptyString;
 667
 668         wxArrayString dirs = GetDirs();
 669         dirs.Add(GetName());
 670
 671         size_t count = dirs.GetCount();
 672         size_t i;
 673         wxString tmpPath;
 674
 675         for ( i = 0; i < count; i++ )
 676         {
 677             // We're using pathOut to collect the long-name path,
 678             // but using a temporary for appending the last path component which may be short-name
 679             tmpPath = pathOut + dirs[i];
 680
 681             if (tmpPath.Last() == wxT(':'))
 682             {
 683                 // Can't pass a drive and root dir to FindFirstFile,
 684                 // so continue to next dir
 685                 tmpPath += wxFILE_SEP_PATH;
 686                 pathOut = tmpPath;
 687                 continue;
 688             }
 689
 690             hFind = ::FindFirstFile(tmpPath, &findFileData);
 691             if (hFind == INVALID_HANDLE_VALUE)
 692             {
 693                 // Error: return immediately with the original path
 694                 return path;
 695             }
 696             else
 697             {
 698                 pathOut += findFileData.cFileName;
 699                 if ( (i < (count-1)) )
 700                     pathOut += wxFILE_SEP_PATH;
 701
 702                 ::FindClose(hFind);
 703             }
 704         }
 705     }
 706
 707     return pathOut;
 708 #else
 709     return GetFullPath();
 710 #endif
 711 }
 712
 713 wxPathFormat wxFileName::GetFormat( wxPathFormat format )
 714 {
 715     if (format == wxPATH_NATIVE)
 716     {
 717 #if defined(__WXMSW__) || defined(__WXPM__)
 718         format = wxPATH_DOS;
 719 #elif defined(__WXMAC__)
 720         format = wxPATH_UNIX; // that's the way the rest of wx' code works right now
 721 #else
 722         format = wxPATH_UNIX;
 723 #endif
 724     }
 725     return format;
 726 }
 727
 728 // ----------------------------------------------------------------------------
 729 // path splitting function
 730 // ----------------------------------------------------------------------------
 731
 732 void wxFileName::SplitPath(const wxString& fullpath,
 733                            wxString *pstrPath,
 734                            wxString *pstrName,
 735                            wxString *pstrExt,
 736                            wxPathFormat format)
 737 {
 738     format = GetFormat(format);
 739
 740     // find the positions of the last dot and last path separator in the path
 741     size_t posLastDot = fullpath.find_last_of(wxFILE_SEP_EXT);
 742     size_t posLastSlash = fullpath.find_last_of(GetPathSeparators(format));
 743
 744     if ( (posLastDot != wxString::npos) && (format == wxPATH_UNIX) )
 745     {
 746         if ( (posLastDot == 0) ||
 747              (fullpath[posLastDot - 1] == wxFILE_SEP_PATH_UNIX) )
 748         {
 749             // under Unix, dot may be (and commonly is) the first character of
 750             // the filename, don't treat the entire filename as extension in
 751             // this case
 752             posLastDot = wxString::npos;
 753         }
 754     }
 755
 756     // if we do have a dot and a slash, check that the dot is in the name part
 757     if ( (posLastDot != wxString::npos) &&
 758          (posLastSlash != wxString::npos) &&
 759          (posLastDot < posLastSlash) )
 760     {
 761         // the dot is part of the path, not the start of the extension
 762         posLastDot = wxString::npos;
 763     }
 764
 765     // now fill in the variables provided by user
 766     if ( pstrPath )
 767     {
 768         if ( posLastSlash == wxString::npos )
 769         {
 770             // no path at all
 771             pstrPath->Empty();
 772         }
 773         else
 774         {
 775             // take all until the separator
 776             *pstrPath = fullpath.Left(posLastSlash);
 777         }
 778     }
 779
 780     if ( pstrName )
 781     {
 782         // take all characters starting from the one after the last slash and
 783         // up to, but excluding, the last dot
 784         size_t nStart = posLastSlash == wxString::npos ? 0 : posLastSlash + 1;
 785         size_t count;
 786         if ( posLastDot == wxString::npos )
 787         {
 788             // take all until the end
 789             count = wxString::npos;
 790         }
 791         else if ( posLastSlash == wxString::npos )
 792         {
 793             count = posLastDot;
 794         }
 795         else // have both dot and slash
 796         {
 797             count = posLastDot - posLastSlash - 1;
 798         }
 799
 800         *pstrName = fullpath.Mid(nStart, count);
 801     }
 802
 803     if ( pstrExt )
 804     {
 805         if ( posLastDot == wxString::npos )
 806         {
 807             // no extension
 808             pstrExt->Empty();
 809         }
 810         else
 811         {
 812             // take everything after the dot
 813             *pstrExt = fullpath.Mid(posLastDot + 1);
 814         }
 815     }
 816 }