src/common/file.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        file.cpp
   3 // Purpose:     wxFile - encapsulates low-level "file descriptor"
   4 //              wxTempFile
   5 // Author:      Vadim Zeitlin
   6 // Modified by:
   7 // Created:     29/01/98
   8 // RCS-ID:      $Id$
   9 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
  10 // Licence:     wxWindows licence
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 /*
  14     TODO: remove all the WinCE ugliness from here, implement the wxOpen(),
  15           wxSeek(), ... functions in a separate file for WinCE instead!!!
  16  */
  17
  18 // ----------------------------------------------------------------------------
  19 // headers
  20 // ----------------------------------------------------------------------------
  21
  22 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  23     #pragma implementation "file.h"
  24 #endif
  25
  26 // For compilers that support precompilation, includes "wx.h".
  27 #include "wx/wxprec.h"
  28
  29 #ifdef __BORLANDC__
  30   #pragma hdrstop
  31 #endif
  32
  33 #if wxUSE_FILE
  34
  35 // standard
  36 #if defined(__WXMSW__) && !defined(__GNUWIN32__) && !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
  37   #include  <io.h>
  38
  39 #ifndef __SALFORDC__
  40     #define   WIN32_LEAN_AND_MEAN
  41     #define   NOSERVICE
  42     #define   NOIME
  43     #define   NOATOM
  44     #define   NOGDI
  45     #define   NOGDICAPMASKS
  46     #define   NOMETAFILE
  47     #define   NOMINMAX
  48     #define   NOMSG
  49     #define   NOOPENFILE
  50     #define   NORASTEROPS
  51     #define   NOSCROLL
  52     #define   NOSOUND
  53     #define   NOSYSMETRICS
  54     #define   NOTEXTMETRIC
  55     #define   NOWH
  56     #define   NOCOMM
  57     #define   NOKANJI
  58     #define   NOCRYPT
  59     #define   NOMCX
  60 #endif
  61
  62 #elif defined(__WXMSW__) && defined(__WXWINCE__)
  63     // TODO: what to include?
  64 #elif (defined(__OS2__))
  65     #include <io.h>
  66 #elif (defined(__UNIX__) || defined(__GNUWIN32__))
  67     #include  <unistd.h>
  68     #include  <time.h>
  69     #include  <sys/stat.h>
  70     #ifdef __GNUWIN32__
  71         #include "wx/msw/wrapwin.h"
  72     #endif
  73 #elif defined(__DOS__)
  74     #if defined(__WATCOMC__)
  75        #include <io.h>
  76     #elif defined(__DJGPP__)
  77        #include <io.h>
  78        #include <unistd.h>
  79        #include <stdio.h>
  80     #else
  81         #error  "Please specify the header with file functions declarations."
  82     #endif
  83 #elif (defined(__WXSTUBS__))
  84     // Have to ifdef this for different environments
  85     #include <io.h>
  86 #elif (defined(__WXMAC__))
  87 #if __MSL__ < 0x6000
  88     int access( const char *path, int mode ) { return 0 ; }
  89 #else
  90     int _access( const char *path, int mode ) { return 0 ; }
  91 #endif
  92     char* mktemp( char * path ) { return path ;}
  93     #include <stat.h>
  94     #include  <unistd.h>
  95 #else
  96     #error  "Please specify the header with file functions declarations."
  97 #endif  //Win/UNIX
  98
  99 #include  <stdio.h>       // SEEK_xxx constants
 100
 101 #ifndef __WXWINCE__
 102 #include  <fcntl.h>       // O_RDONLY &c
 103 #endif
 104
 105 #ifdef __WXWINCE__
 106 // Nothing
 107 #elif !defined(__MWERKS__)
 108     #include  <sys/types.h>   // needed for stat
 109     #include  <sys/stat.h>    // stat
 110 #elif defined(__MWERKS__) && ( defined(__WXMSW__) || defined(__MACH__) )
 111     #include  <sys/types.h>   // needed for stat
 112     #include  <sys/stat.h>    // stat
 113 #endif
 114
 115 // Windows compilers don't have these constants
 116 #ifndef W_OK
 117     enum
 118     {
 119         F_OK = 0,   // test for existence
 120         X_OK = 1,   //          execute permission
 121         W_OK = 2,   //          write
 122         R_OK = 4    //          read
 123     };
 124 #endif // W_OK
 125
 126 // there is no distinction between text and binary files under Unix, so define
 127 // O_BINARY as 0 if the system headers don't do it already
 128 #if defined(__UNIX__) && !defined(O_BINARY)
 129     #define   O_BINARY    (0)
 130 #endif  //__UNIX__
 131
 132 #ifdef __SALFORDC__
 133     #include <unix.h>
 134 #endif
 135
 136 #ifndef MAX_PATH
 137     #define MAX_PATH 512
 138 #endif
 139
 140 // some broken compilers don't have 3rd argument in open() and creat()
 141 #ifdef __SALFORDC__
 142     #define ACCESS(access)
 143     #define stat    _stat
 144 #else // normal compiler
 145     #define ACCESS(access)  , (access)
 146 #endif // Salford C
 147
 148 // wxWidgets
 149 #ifndef WX_PRECOMP
 150     #include  "wx/string.h"
 151     #include  "wx/intl.h"
 152     #include  "wx/log.h"
 153 #endif // !WX_PRECOMP
 154
 155 #include  "wx/filename.h"
 156 #include  "wx/file.h"
 157 #include  "wx/filefn.h"
 158
 159 #ifdef __WXMSW__
 160     #include "wx/msw/mslu.h"
 161 #endif
 162
 163 #ifdef __WXWINCE__
 164     #include "wx/msw/private.h"
 165 #endif
 166
 167 // ============================================================================
 168 // implementation of wxFile
 169 // ============================================================================
 170
 171 // ----------------------------------------------------------------------------
 172 // static functions
 173 // ----------------------------------------------------------------------------
 174
 175 bool wxFile::Exists(const wxChar *name)
 176 {
 177     return wxFileExists(name);
 178 }
 179
 180 bool wxFile::Access(const wxChar *name, OpenMode mode)
 181 {
 182     int how;
 183
 184     switch ( mode )
 185     {
 186         default:
 187             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 188             // fall through
 189
 190         case read:
 191             how = R_OK;
 192             break;
 193
 194         case write:
 195             how = W_OK;
 196             break;
 197
 198         case read_write:
 199             how = R_OK | W_OK;
 200             break;
 201     }
 202
 203 #ifdef __WXWINCE__
 204     // FIXME: use CreateFile with 0 access to query the file
 205     return true;
 206 #else
 207     return wxAccess(name, how) == 0;
 208 #endif
 209 }
 210
 211 // ----------------------------------------------------------------------------
 212 // opening/closing
 213 // ----------------------------------------------------------------------------
 214
 215 // ctors
 216 wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
 217 {
 218     m_fd = fd_invalid;
 219     m_error = false;
 220
 221     Open(szFileName, mode);
 222 }
 223
 224 // create the file, fail if it already exists and bOverwrite
 225 bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
 226 {
 227     // if bOverwrite we create a new file or truncate the existing one,
 228     // otherwise we only create the new file and fail if it already exists
 229 #if defined(__WXMAC__) && !defined(__UNIX__) && !wxUSE_UNICODE
 230     // Dominic Mazzoni [dmazzoni+@cs.cmu.edu] reports that open is still broken on the mac, so we replace
 231     // int fd = open( szFileName , O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 232     int fd = creat( szFileName , accessMode);
 233 #else
 234 #ifdef __WXWINCE__
 235     HANDLE fileHandle = ::CreateFile(szFileName, GENERIC_WRITE, 0, NULL,
 236         bOverwrite ? CREATE_ALWAYS : CREATE_NEW, FILE_ATTRIBUTE_NORMAL,
 237         0);
 238     int fd = 0;
 239     if (fileHandle == INVALID_HANDLE_VALUE)
 240         fd = (int) fileHandle;
 241     else
 242         fd = -1;
 243 #else
 244     int fd = wxOpen( szFileName,
 245                      O_BINARY | O_WRONLY | O_CREAT |
 246                      (bOverwrite ? O_TRUNC : O_EXCL)
 247                      ACCESS(accessMode) );
 248 #endif
 249 #endif
 250     if ( fd == -1 )
 251     {
 252         wxLogSysError(_("can't create file '%s'"), szFileName);
 253         return false;
 254     }
 255     else
 256     {
 257         Attach(fd);
 258         return true;
 259     }
 260 }
 261
 262 // open the file
 263 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 264 {
 265 #ifdef __WXWINCE__
 266     DWORD access = 0;
 267     DWORD shareMode = 0;
 268     DWORD disposition = 0;
 269
 270     int flags = O_BINARY;
 271
 272     switch ( mode )
 273     {
 274         case read:
 275             access = GENERIC_READ;
 276             shareMode = FILE_SHARE_READ|FILE_SHARE_WRITE;
 277             disposition = OPEN_EXISTING;
 278             break;
 279
 280         case write_append:
 281             if ( wxFile::Exists(szFileName) )
 282             {
 283                 access = GENERIC_READ|GENERIC_WRITE;
 284                 shareMode = FILE_SHARE_READ;
 285                 disposition = 0;
 286                 break;
 287             }
 288             //else: fall through as write_append is the same as write if the
 289             //      file doesn't exist
 290
 291         case write:
 292             access = GENERIC_WRITE;
 293             shareMode = 0;
 294             disposition = TRUNCATE_EXISTING;
 295             break;
 296
 297         case write_excl:
 298             access = GENERIC_WRITE;
 299             shareMode = 0;
 300             disposition = TRUNCATE_EXISTING;
 301             break;
 302
 303         case read_write:
 304             access = GENERIC_READ|GENERIC_WRITE;
 305             shareMode = 0;
 306             disposition = 0;
 307             break;
 308     }
 309
 310     int fd = 0;
 311     HANDLE fileHandle = ::CreateFile(szFileName, access, shareMode, NULL,
 312         disposition, FILE_ATTRIBUTE_NORMAL, 0);
 313     if (fileHandle == INVALID_HANDLE_VALUE)
 314         fd = -1;
 315     else
 316         fd = (int) fileHandle;
 317 #else
 318     int flags = O_BINARY;
 319
 320     switch ( mode )
 321     {
 322         case read:
 323             flags |= O_RDONLY;
 324             break;
 325
 326         case write_append:
 327             if ( wxFile::Exists(szFileName) )
 328             {
 329                 flags |= O_WRONLY | O_APPEND;
 330                 break;
 331             }
 332             //else: fall through as write_append is the same as write if the
 333             //      file doesn't exist
 334
 335         case write:
 336             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 337             break;
 338
 339         case write_excl:
 340             flags |= O_WRONLY | O_CREAT | O_EXCL;
 341             break;
 342
 343         case read_write:
 344             flags |= O_RDWR;
 345             break;
 346     }
 347
 348 #ifdef __WINDOWS__
 349     // only read/write bits for "all" are supported by this function under
 350     // Windows, and VC++ 8 returns EINVAL if any other bits are used in
 351     // accessMode, so clear them as they have at best no effect anyhow
 352     accessMode &= wxS_IRUSR | wxS_IWUSR;
 353 #endif // __WINDOWS__
 354
 355     int fd = wxOpen( szFileName, flags ACCESS(accessMode));
 356 #endif
 357     if ( fd == -1 )
 358     {
 359         wxLogSysError(_("can't open file '%s'"), szFileName);
 360         return false;
 361     }
 362     else {
 363         Attach(fd);
 364         return true;
 365     }
 366 }
 367
 368 // close
 369 bool wxFile::Close()
 370 {
 371     if ( IsOpened() ) {
 372 #ifdef __WXWINCE__
 373         if (!CloseHandle((HANDLE) m_fd))
 374 #else
 375         if ( close(m_fd) == -1 )
 376 #endif
 377         {
 378             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 379             m_fd = fd_invalid;
 380             return false;
 381         }
 382         else
 383             m_fd = fd_invalid;
 384     }
 385
 386     return true;
 387 }
 388
 389 // ----------------------------------------------------------------------------
 390 // read/write
 391 // ----------------------------------------------------------------------------
 392
 393 // read
 394 off_t wxFile::Read(void *pBuf, off_t nCount)
 395 {
 396     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 397
 398 #ifdef __WXWINCE__
 399     DWORD bytesRead = 0;
 400     int iRc = 0;
 401     if (ReadFile((HANDLE) m_fd, pBuf, (DWORD) nCount, & bytesRead, NULL))
 402         iRc = bytesRead;
 403     else
 404         iRc = -1;
 405 #elif defined(__MWERKS__)
 406     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 407 #else
 408     int iRc = ::read(m_fd, pBuf, nCount);
 409 #endif
 410     if ( iRc == -1 ) {
 411         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 412         return wxInvalidOffset;
 413     }
 414     else
 415         return (size_t)iRc;
 416 }
 417
 418 // write
 419 size_t wxFile::Write(const void *pBuf, size_t nCount)
 420 {
 421     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 422
 423 #ifdef __WXWINCE__
 424     DWORD bytesWritten = 0;
 425     int iRc = 0;
 426     if (WriteFile((HANDLE) m_fd, pBuf, (DWORD) nCount, & bytesWritten, NULL))
 427         iRc = bytesWritten;
 428     else
 429         iRc = -1;
 430 #elif defined(__MWERKS__)
 431 #if __MSL__ >= 0x6000
 432     int iRc = ::write(m_fd, (void*) pBuf, nCount);
 433 #else
 434     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 435 #endif
 436 #else
 437     int iRc = ::write(m_fd, pBuf, nCount);
 438 #endif
 439     if ( iRc == -1 ) {
 440         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 441         m_error = true;
 442         return 0;
 443     }
 444     else
 445         return iRc;
 446 }
 447
 448 // flush
 449 bool wxFile::Flush()
 450 {
 451     if ( IsOpened() ) {
 452 #ifdef __WXWINCE__
 453         // Do nothing
 454 #elif defined(__VISUALC__) || wxHAVE_FSYNC
 455         if ( wxFsync(m_fd) == -1 )
 456         {
 457             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 458             return false;
 459         }
 460 #else // no fsync
 461         // just do nothing
 462 #endif // fsync
 463     }
 464
 465     return true;
 466 }
 467
 468 // ----------------------------------------------------------------------------
 469 // seek
 470 // ----------------------------------------------------------------------------
 471
 472 // seek
 473 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 474 {
 475     wxASSERT( IsOpened() );
 476
 477 #ifdef __WXWINCE__
 478     int origin;
 479     switch ( mode ) {
 480         default:
 481             wxFAIL_MSG(_("unknown seek origin"));
 482
 483         case wxFromStart:
 484             origin = FILE_BEGIN;
 485             break;
 486
 487         case wxFromCurrent:
 488             origin = FILE_CURRENT;
 489             break;
 490
 491         case wxFromEnd:
 492             origin = FILE_END;
 493             break;
 494     }
 495
 496     DWORD res = SetFilePointer((HANDLE) m_fd, ofs, 0, origin) ;
 497     if (res == 0xFFFFFFFF && GetLastError() != NO_ERROR)
 498     {
 499         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 500         return wxInvalidOffset;
 501     }
 502     else
 503         return (off_t)res;
 504 #else
 505     int origin;
 506     switch ( mode ) {
 507         default:
 508             wxFAIL_MSG(_("unknown seek origin"));
 509
 510         case wxFromStart:
 511             origin = SEEK_SET;
 512             break;
 513
 514         case wxFromCurrent:
 515             origin = SEEK_CUR;
 516             break;
 517
 518         case wxFromEnd:
 519             origin = SEEK_END;
 520             break;
 521     }
 522
 523     int iRc = lseek(m_fd, ofs, origin);
 524     if ( iRc == -1 ) {
 525         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 526         return wxInvalidOffset;
 527     }
 528     else
 529         return (off_t)iRc;
 530 #endif
 531 }
 532
 533 // get current off_t
 534 off_t wxFile::Tell() const
 535 {
 536     wxASSERT( IsOpened() );
 537
 538 #ifdef __WXWINCE__
 539     DWORD res = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT) ;
 540     if (res == 0xFFFFFFFF && GetLastError() != NO_ERROR)
 541     {
 542         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 543         return wxInvalidOffset;
 544     }
 545     else
 546         return (off_t)res;
 547 #else
 548     int iRc = wxTell(m_fd);
 549     if ( iRc == -1 ) {
 550         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 551         return wxInvalidOffset;
 552     }
 553     else
 554         return (off_t)iRc;
 555 #endif
 556 }
 557
 558 // get current file length
 559 off_t wxFile::Length() const
 560 {
 561     wxASSERT( IsOpened() );
 562
 563 #ifdef __WXWINCE__
 564     DWORD off0 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT);
 565     DWORD off1 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_END);
 566     off_t len = off1;
 567
 568     // Restore position
 569     SetFilePointer((HANDLE) m_fd, off0, 0, FILE_BEGIN);
 570     return len;
 571 #else
 572 #ifdef __VISUALC__
 573     int iRc = _filelength(m_fd);
 574 #else // !VC++
 575     int iRc = wxTell(m_fd);
 576     if ( iRc != -1 ) {
 577         // @ have to use const_cast :-(
 578         int iLen = ((wxFile *)this)->SeekEnd();
 579         if ( iLen != -1 ) {
 580             // restore old position
 581             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 582                 // error
 583                 iLen = -1;
 584             }
 585         }
 586
 587         iRc = iLen;
 588     }
 589 #endif  // VC++
 590
 591     if ( iRc == -1 ) {
 592         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 593         return wxInvalidOffset;
 594     }
 595     else
 596         return (off_t)iRc;
 597 #endif
 598 }
 599
 600 // is end of file reached?
 601 bool wxFile::Eof() const
 602 {
 603     wxASSERT( IsOpened() );
 604
 605 #ifdef __WXWINCE__
 606     DWORD off0 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT);
 607     DWORD off1 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_END);
 608     if (off0 == off1)
 609         return true;
 610     else
 611     {
 612         SetFilePointer((HANDLE) m_fd, off0, 0, FILE_BEGIN);
 613         return false;
 614     }
 615 #else
 616     int iRc;
 617
 618 #if defined(__DOS__) || defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 619     // @@ this doesn't work, of course, on unseekable file descriptors
 620     off_t ofsCur = Tell(),
 621     ofsMax = Length();
 622     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 623         iRc = -1;
 624     else
 625         iRc = ofsCur == ofsMax;
 626 #else  // Windows and "native" compiler
 627     iRc = eof(m_fd);
 628 #endif // Windows/Unix
 629
 630     switch ( iRc ) {
 631         case 1:
 632             break;
 633
 634         case 0:
 635             return false;
 636
 637         case -1:
 638             wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
 639                 break;
 640
 641         default:
 642             wxFAIL_MSG(_("invalid eof() return value."));
 643     }
 644
 645     return true;
 646 #endif
 647 }
 648
 649 // ============================================================================
 650 // implementation of wxTempFile
 651 // ============================================================================
 652
 653 // ----------------------------------------------------------------------------
 654 // construction
 655 // ----------------------------------------------------------------------------
 656
 657 wxTempFile::wxTempFile(const wxString& strName)
 658 {
 659     Open(strName);
 660 }
 661
 662 bool wxTempFile::Open(const wxString& strName)
 663 {
 664     // we must have an absolute filename because otherwise CreateTempFileName()
 665     // would create the temp file in $TMP (i.e. the system standard location
 666     // for the temp files) which might be on another volume/drive/mount and
 667     // wxRename()ing it later to m_strName from Commit() would then fail
 668     //
 669     // with the absolute filename, the temp file is created in the same
 670     // directory as this one which ensures that wxRename() may work later
 671     wxFileName fn(strName);
 672     if ( !fn.IsAbsolute() )
 673     {
 674         fn.Normalize(wxPATH_NORM_ABSOLUTE);
 675     }
 676
 677     m_strName = fn.GetFullPath();
 678
 679     m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);
 680
 681     if ( m_strTemp.empty() )
 682     {
 683         // CreateTempFileName() failed
 684         return false;
 685     }
 686
 687 #ifdef __UNIX__
 688     // the temp file should have the same permissions as the original one
 689     mode_t mode;
 690
 691     wxStructStat st;
 692     if ( stat( (const char*) m_strName.fn_str(), &st) == 0 )
 693     {
 694         mode = st.st_mode;
 695     }
 696     else
 697     {
 698         // file probably didn't exist, just give it the default mode _using_
 699         // user's umask (new files creation should respect umask)
 700         mode_t mask = umask(0777);
 701         mode = 0666 & ~mask;
 702         umask(mask);
 703     }
 704
 705     if ( chmod( (const char*) m_strTemp.fn_str(), mode) == -1 )
 706     {
 707 #ifndef __OS2__
 708         wxLogSysError(_("Failed to set temporary file permissions"));
 709 #endif
 710     }
 711 #endif // Unix
 712
 713     return true;
 714 }
 715
 716 // ----------------------------------------------------------------------------
 717 // destruction
 718 // ----------------------------------------------------------------------------
 719
 720 wxTempFile::~wxTempFile()
 721 {
 722     if ( IsOpened() )
 723         Discard();
 724 }
 725
 726 bool wxTempFile::Commit()
 727 {
 728     m_file.Close();
 729
 730     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 731         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 732         return false;
 733     }
 734
 735     if ( !wxRenameFile(m_strTemp, m_strName)  ) {
 736         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 737         return false;
 738     }
 739
 740     return true;
 741 }
 742
 743 void wxTempFile::Discard()
 744 {
 745     m_file.Close();
 746     if ( wxRemove(m_strTemp) != 0 )
 747         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 748 }
 749
 750 #endif // wxUSE_FILE
 751