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     switch ( mode )
 271     {
 272         case read:
 273             access = GENERIC_READ;
 274             shareMode = FILE_SHARE_READ|FILE_SHARE_WRITE;
 275             disposition = OPEN_EXISTING;
 276             break;
 277
 278         case write_append:
 279             if ( wxFile::Exists(szFileName) )
 280             {
 281                 access = GENERIC_READ|GENERIC_WRITE;
 282                 shareMode = FILE_SHARE_READ;
 283                 disposition = 0;
 284                 break;
 285             }
 286             //else: fall through as write_append is the same as write if the
 287             //      file doesn't exist
 288
 289         case write:
 290             access = GENERIC_WRITE;
 291             shareMode = 0;
 292             disposition = TRUNCATE_EXISTING;
 293             break;
 294
 295         case write_excl:
 296             access = GENERIC_WRITE;
 297             shareMode = 0;
 298             disposition = TRUNCATE_EXISTING;
 299             break;
 300
 301         case read_write:
 302             access = GENERIC_READ|GENERIC_WRITE;
 303             shareMode = 0;
 304             disposition = 0;
 305             break;
 306     }
 307
 308     int fd = 0;
 309     HANDLE fileHandle = ::CreateFile(szFileName, access, shareMode, NULL,
 310         disposition, FILE_ATTRIBUTE_NORMAL, 0);
 311     if (fileHandle == INVALID_HANDLE_VALUE)
 312         fd = -1;
 313     else
 314         fd = (int) fileHandle;
 315 #else
 316     int flags = O_BINARY;
 317
 318     switch ( mode )
 319     {
 320         case read:
 321             flags |= O_RDONLY;
 322             break;
 323
 324         case write_append:
 325             if ( wxFile::Exists(szFileName) )
 326             {
 327                 flags |= O_WRONLY | O_APPEND;
 328                 break;
 329             }
 330             //else: fall through as write_append is the same as write if the
 331             //      file doesn't exist
 332
 333         case write:
 334             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 335             break;
 336
 337         case write_excl:
 338             flags |= O_WRONLY | O_CREAT | O_EXCL;
 339             break;
 340
 341         case read_write:
 342             flags |= O_RDWR;
 343             break;
 344     }
 345
 346 #ifdef __WINDOWS__
 347     // only read/write bits for "all" are supported by this function under
 348     // Windows, and VC++ 8 returns EINVAL if any other bits are used in
 349     // accessMode, so clear them as they have at best no effect anyhow
 350     accessMode &= wxS_IRUSR | wxS_IWUSR;
 351 #endif // __WINDOWS__
 352
 353     int fd = wxOpen( szFileName, flags ACCESS(accessMode));
 354 #endif
 355     if ( fd == -1 )
 356     {
 357         wxLogSysError(_("can't open file '%s'"), szFileName);
 358         return false;
 359     }
 360     else {
 361         Attach(fd);
 362         return true;
 363     }
 364 }
 365
 366 // close
 367 bool wxFile::Close()
 368 {
 369     if ( IsOpened() ) {
 370 #ifdef __WXWINCE__
 371         if (!CloseHandle((HANDLE) m_fd))
 372 #else
 373         if ( close(m_fd) == -1 )
 374 #endif
 375         {
 376             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 377             m_fd = fd_invalid;
 378             return false;
 379         }
 380         else
 381             m_fd = fd_invalid;
 382     }
 383
 384     return true;
 385 }
 386
 387 // ----------------------------------------------------------------------------
 388 // read/write
 389 // ----------------------------------------------------------------------------
 390
 391 // read
 392 off_t wxFile::Read(void *pBuf, off_t nCount)
 393 {
 394     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 395
 396 #ifdef __WXWINCE__
 397     DWORD bytesRead = 0;
 398     int iRc = 0;
 399     if (ReadFile((HANDLE) m_fd, pBuf, (DWORD) nCount, & bytesRead, NULL))
 400         iRc = bytesRead;
 401     else
 402         iRc = -1;
 403 #elif defined(__MWERKS__)
 404     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 405 #else
 406     int iRc = ::read(m_fd, pBuf, nCount);
 407 #endif
 408     if ( iRc == -1 ) {
 409         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 410         return wxInvalidOffset;
 411     }
 412     else
 413         return (size_t)iRc;
 414 }
 415
 416 // write
 417 size_t wxFile::Write(const void *pBuf, size_t nCount)
 418 {
 419     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 420
 421 #ifdef __WXWINCE__
 422     DWORD bytesWritten = 0;
 423     int iRc = 0;
 424     if (WriteFile((HANDLE) m_fd, pBuf, (DWORD) nCount, & bytesWritten, NULL))
 425         iRc = bytesWritten;
 426     else
 427         iRc = -1;
 428 #elif defined(__MWERKS__)
 429 #if __MSL__ >= 0x6000
 430     int iRc = ::write(m_fd, (void*) pBuf, nCount);
 431 #else
 432     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 433 #endif
 434 #else
 435     int iRc = ::write(m_fd, pBuf, nCount);
 436 #endif
 437     if ( iRc == -1 ) {
 438         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 439         m_error = true;
 440         return 0;
 441     }
 442     else
 443         return iRc;
 444 }
 445
 446 // flush
 447 bool wxFile::Flush()
 448 {
 449     if ( IsOpened() ) {
 450 #ifdef __WXWINCE__
 451         // Do nothing
 452 #elif defined(__VISUALC__) || wxHAVE_FSYNC
 453         if ( wxFsync(m_fd) == -1 )
 454         {
 455             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 456             return false;
 457         }
 458 #else // no fsync
 459         // just do nothing
 460 #endif // fsync
 461     }
 462
 463     return true;
 464 }
 465
 466 // ----------------------------------------------------------------------------
 467 // seek
 468 // ----------------------------------------------------------------------------
 469
 470 // seek
 471 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 472 {
 473     wxASSERT( IsOpened() );
 474
 475 #ifdef __WXWINCE__
 476     int origin;
 477     switch ( mode ) {
 478         default:
 479             wxFAIL_MSG(_("unknown seek origin"));
 480
 481         case wxFromStart:
 482             origin = FILE_BEGIN;
 483             break;
 484
 485         case wxFromCurrent:
 486             origin = FILE_CURRENT;
 487             break;
 488
 489         case wxFromEnd:
 490             origin = FILE_END;
 491             break;
 492     }
 493
 494     DWORD res = SetFilePointer((HANDLE) m_fd, ofs, 0, origin) ;
 495     if (res == 0xFFFFFFFF && GetLastError() != NO_ERROR)
 496     {
 497         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 498         return wxInvalidOffset;
 499     }
 500     else
 501         return (off_t)res;
 502 #else
 503     int origin;
 504     switch ( mode ) {
 505         default:
 506             wxFAIL_MSG(_("unknown seek origin"));
 507
 508         case wxFromStart:
 509             origin = SEEK_SET;
 510             break;
 511
 512         case wxFromCurrent:
 513             origin = SEEK_CUR;
 514             break;
 515
 516         case wxFromEnd:
 517             origin = SEEK_END;
 518             break;
 519     }
 520
 521     int iRc = lseek(m_fd, ofs, origin);
 522     if ( iRc == -1 ) {
 523         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 524         return wxInvalidOffset;
 525     }
 526     else
 527         return (off_t)iRc;
 528 #endif
 529 }
 530
 531 // get current off_t
 532 off_t wxFile::Tell() const
 533 {
 534     wxASSERT( IsOpened() );
 535
 536 #ifdef __WXWINCE__
 537     DWORD res = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT) ;
 538     if (res == 0xFFFFFFFF && GetLastError() != NO_ERROR)
 539     {
 540         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 541         return wxInvalidOffset;
 542     }
 543     else
 544         return (off_t)res;
 545 #else
 546     int iRc = wxTell(m_fd);
 547     if ( iRc == -1 ) {
 548         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 549         return wxInvalidOffset;
 550     }
 551     else
 552         return (off_t)iRc;
 553 #endif
 554 }
 555
 556 // get current file length
 557 off_t wxFile::Length() const
 558 {
 559     wxASSERT( IsOpened() );
 560
 561 #ifdef __WXWINCE__
 562     DWORD off0 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT);
 563     DWORD off1 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_END);
 564     off_t len = off1;
 565
 566     // Restore position
 567     SetFilePointer((HANDLE) m_fd, off0, 0, FILE_BEGIN);
 568     return len;
 569 #else
 570 #ifdef __VISUALC__
 571     int iRc = _filelength(m_fd);
 572 #else // !VC++
 573     int iRc = wxTell(m_fd);
 574     if ( iRc != -1 ) {
 575         // @ have to use const_cast :-(
 576         int iLen = ((wxFile *)this)->SeekEnd();
 577         if ( iLen != -1 ) {
 578             // restore old position
 579             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 580                 // error
 581                 iLen = -1;
 582             }
 583         }
 584
 585         iRc = iLen;
 586     }
 587 #endif  // VC++
 588
 589     if ( iRc == -1 ) {
 590         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 591         return wxInvalidOffset;
 592     }
 593     else
 594         return (off_t)iRc;
 595 #endif
 596 }
 597
 598 // is end of file reached?
 599 bool wxFile::Eof() const
 600 {
 601     wxASSERT( IsOpened() );
 602
 603 #ifdef __WXWINCE__
 604     DWORD off0 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT);
 605     DWORD off1 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_END);
 606     if (off0 == off1)
 607         return true;
 608     else
 609     {
 610         SetFilePointer((HANDLE) m_fd, off0, 0, FILE_BEGIN);
 611         return false;
 612     }
 613 #else
 614     int iRc;
 615
 616 #if defined(__DOS__) || defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 617     // @@ this doesn't work, of course, on unseekable file descriptors
 618     off_t ofsCur = Tell(),
 619     ofsMax = Length();
 620     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 621         iRc = -1;
 622     else
 623         iRc = ofsCur == ofsMax;
 624 #else  // Windows and "native" compiler
 625     iRc = eof(m_fd);
 626 #endif // Windows/Unix
 627
 628     switch ( iRc ) {
 629         case 1:
 630             break;
 631
 632         case 0:
 633             return false;
 634
 635         case -1:
 636             wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
 637                 break;
 638
 639         default:
 640             wxFAIL_MSG(_("invalid eof() return value."));
 641     }
 642
 643     return true;
 644 #endif
 645 }
 646
 647 // ============================================================================
 648 // implementation of wxTempFile
 649 // ============================================================================
 650
 651 // ----------------------------------------------------------------------------
 652 // construction
 653 // ----------------------------------------------------------------------------
 654
 655 wxTempFile::wxTempFile(const wxString& strName)
 656 {
 657     Open(strName);
 658 }
 659
 660 bool wxTempFile::Open(const wxString& strName)
 661 {
 662     // we must have an absolute filename because otherwise CreateTempFileName()
 663     // would create the temp file in $TMP (i.e. the system standard location
 664     // for the temp files) which might be on another volume/drive/mount and
 665     // wxRename()ing it later to m_strName from Commit() would then fail
 666     //
 667     // with the absolute filename, the temp file is created in the same
 668     // directory as this one which ensures that wxRename() may work later
 669     wxFileName fn(strName);
 670     if ( !fn.IsAbsolute() )
 671     {
 672         fn.Normalize(wxPATH_NORM_ABSOLUTE);
 673     }
 674
 675     m_strName = fn.GetFullPath();
 676
 677     m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);
 678
 679     if ( m_strTemp.empty() )
 680     {
 681         // CreateTempFileName() failed
 682         return false;
 683     }
 684
 685 #ifdef __UNIX__
 686     // the temp file should have the same permissions as the original one
 687     mode_t mode;
 688
 689     wxStructStat st;
 690     if ( stat( (const char*) m_strName.fn_str(), &st) == 0 )
 691     {
 692         mode = st.st_mode;
 693     }
 694     else
 695     {
 696         // file probably didn't exist, just give it the default mode _using_
 697         // user's umask (new files creation should respect umask)
 698         mode_t mask = umask(0777);
 699         mode = 0666 & ~mask;
 700         umask(mask);
 701     }
 702
 703     if ( chmod( (const char*) m_strTemp.fn_str(), mode) == -1 )
 704     {
 705 #ifndef __OS2__
 706         wxLogSysError(_("Failed to set temporary file permissions"));
 707 #endif
 708     }
 709 #endif // Unix
 710
 711     return true;
 712 }
 713
 714 // ----------------------------------------------------------------------------
 715 // destruction
 716 // ----------------------------------------------------------------------------
 717
 718 wxTempFile::~wxTempFile()
 719 {
 720     if ( IsOpened() )
 721         Discard();
 722 }
 723
 724 bool wxTempFile::Commit()
 725 {
 726     m_file.Close();
 727
 728     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 729         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 730         return false;
 731     }
 732
 733     if ( !wxRenameFile(m_strTemp, m_strName)  ) {
 734         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 735         return false;
 736     }
 737
 738     return true;
 739 }
 740
 741 void wxTempFile::Discard()
 742 {
 743     m_file.Close();
 744     if ( wxRemove(m_strTemp) != 0 )
 745         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 746 }
 747
 748 #endif // wxUSE_FILE
 749