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(__UNIX__) || defined(__GNUWIN32__))
  65     #include  <unistd.h>
  66     #include  <time.h>
  67     #include  <sys/stat.h>
  68     #ifdef __GNUWIN32__
  69         #include "wx/msw/wrapwin.h"
  70     #endif
  71 #elif defined(__DOS__)
  72     #if defined(__WATCOMC__)
  73        #include <io.h>
  74     #elif defined(__DJGPP__)
  75        #include <io.h>
  76        #include <unistd.h>
  77        #include <stdio.h>
  78     #else
  79         #error  "Please specify the header with file functions declarations."
  80     #endif
  81 #elif (defined(__WXPM__))
  82     #include <io.h>
  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 // wxWindows
 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(wxUnix2MacFilename( 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     int fd = wxOpen( szFileName, flags ACCESS(accessMode));
 349 #endif
 350     if ( fd == -1 )
 351     {
 352         wxLogSysError(_("can't open file '%s'"), szFileName);
 353         return FALSE;
 354     }
 355     else {
 356         Attach(fd);
 357         return TRUE;
 358     }
 359 }
 360
 361 // close
 362 bool wxFile::Close()
 363 {
 364     if ( IsOpened() ) {
 365 #ifdef __WXWINCE__
 366         if (!CloseHandle((HANDLE) m_fd))
 367 #else
 368         if ( close(m_fd) == -1 )
 369 #endif
 370         {
 371             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 372             m_fd = fd_invalid;
 373             return FALSE;
 374         }
 375         else
 376             m_fd = fd_invalid;
 377     }
 378
 379     return TRUE;
 380 }
 381
 382 // ----------------------------------------------------------------------------
 383 // read/write
 384 // ----------------------------------------------------------------------------
 385
 386 // read
 387 off_t wxFile::Read(void *pBuf, off_t nCount)
 388 {
 389     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 390
 391 #ifdef __WXWINCE__
 392     DWORD bytesRead = 0;
 393     int iRc = 0;
 394     if (ReadFile((HANDLE) m_fd, pBuf, (DWORD) nCount, & bytesRead, NULL))
 395         iRc = bytesRead;
 396     else
 397         iRc = -1;
 398 #elif defined(__MWERKS__)
 399     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 400 #else
 401     int iRc = ::read(m_fd, pBuf, nCount);
 402 #endif
 403     if ( iRc == -1 ) {
 404         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 405         return wxInvalidOffset;
 406     }
 407     else
 408         return (size_t)iRc;
 409 }
 410
 411 // write
 412 size_t wxFile::Write(const void *pBuf, size_t nCount)
 413 {
 414     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 415
 416 #ifdef __WXWINCE__
 417     DWORD bytesRead = 0;
 418     int iRc = 0;
 419     if (WriteFile((HANDLE) m_fd, pBuf, (DWORD) nCount, & bytesRead, NULL))
 420         iRc = bytesRead;
 421     else
 422         iRc = -1;
 423 #elif defined(__MWERKS__)
 424 #if __MSL__ >= 0x6000
 425     int iRc = ::write(m_fd, (void*) pBuf, nCount);
 426 #else
 427     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 428 #endif
 429 #else
 430     int iRc = ::write(m_fd, pBuf, nCount);
 431 #endif
 432     if ( iRc == -1 ) {
 433         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 434         m_error = TRUE;
 435         return 0;
 436     }
 437     else
 438         return iRc;
 439 }
 440
 441 // flush
 442 bool wxFile::Flush()
 443 {
 444     if ( IsOpened() ) {
 445 #ifdef __WXWINCE__
 446         // Do nothing
 447 #elif defined(__VISUALC__) || wxHAVE_FSYNC
 448         if ( wxFsync(m_fd) == -1 )
 449         {
 450             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 451             return FALSE;
 452         }
 453 #else // no fsync
 454         // just do nothing
 455 #endif // fsync
 456     }
 457
 458     return TRUE;
 459 }
 460
 461 // ----------------------------------------------------------------------------
 462 // seek
 463 // ----------------------------------------------------------------------------
 464
 465 // seek
 466 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 467 {
 468     wxASSERT( IsOpened() );
 469
 470 #ifdef __WXWINCE__
 471     int origin;
 472     switch ( mode ) {
 473         default:
 474             wxFAIL_MSG(_("unknown seek origin"));
 475
 476         case wxFromStart:
 477             origin = FILE_BEGIN;
 478             break;
 479
 480         case wxFromCurrent:
 481             origin = FILE_CURRENT;
 482             break;
 483
 484         case wxFromEnd:
 485             origin = FILE_END;
 486             break;
 487     }
 488
 489     DWORD res = SetFilePointer((HANDLE) m_fd, ofs, 0, origin) ;
 490     if (res == 0xFFFFFFFF && GetLastError() != NO_ERROR)
 491     {
 492         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 493         return wxInvalidOffset;
 494     }
 495     else
 496         return (off_t)res;
 497 #else
 498     int origin;
 499     switch ( mode ) {
 500         default:
 501             wxFAIL_MSG(_("unknown seek origin"));
 502
 503         case wxFromStart:
 504             origin = SEEK_SET;
 505             break;
 506
 507         case wxFromCurrent:
 508             origin = SEEK_CUR;
 509             break;
 510
 511         case wxFromEnd:
 512             origin = SEEK_END;
 513             break;
 514     }
 515
 516     int iRc = lseek(m_fd, ofs, origin);
 517     if ( iRc == -1 ) {
 518         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 519         return wxInvalidOffset;
 520     }
 521     else
 522         return (off_t)iRc;
 523 #endif
 524 }
 525
 526 // get current off_t
 527 off_t wxFile::Tell() const
 528 {
 529     wxASSERT( IsOpened() );
 530
 531 #ifdef __WXWINCE__
 532     DWORD res = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT) ;
 533     if (res == 0xFFFFFFFF && GetLastError() != NO_ERROR)
 534     {
 535         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 536         return wxInvalidOffset;
 537     }
 538     else
 539         return (off_t)res;
 540 #else
 541     int iRc = wxTell(m_fd);
 542     if ( iRc == -1 ) {
 543         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 544         return wxInvalidOffset;
 545     }
 546     else
 547         return (off_t)iRc;
 548 #endif
 549 }
 550
 551 // get current file length
 552 off_t wxFile::Length() const
 553 {
 554     wxASSERT( IsOpened() );
 555
 556 #ifdef __WXWINCE__
 557     DWORD off0 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT);
 558     DWORD off1 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_END);
 559     off_t len = off1;
 560
 561     // Restore position
 562     SetFilePointer((HANDLE) m_fd, off0, 0, FILE_BEGIN);
 563     return len;
 564 #else
 565 #ifdef __VISUALC__
 566     int iRc = _filelength(m_fd);
 567 #else // !VC++
 568     int iRc = wxTell(m_fd);
 569     if ( iRc != -1 ) {
 570         // @ have to use const_cast :-(
 571         int iLen = ((wxFile *)this)->SeekEnd();
 572         if ( iLen != -1 ) {
 573             // restore old position
 574             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 575                 // error
 576                 iLen = -1;
 577             }
 578         }
 579
 580         iRc = iLen;
 581     }
 582 #endif  // VC++
 583
 584     if ( iRc == -1 ) {
 585         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 586         return wxInvalidOffset;
 587     }
 588     else
 589         return (off_t)iRc;
 590 #endif
 591 }
 592
 593 // is end of file reached?
 594 bool wxFile::Eof() const
 595 {
 596     wxASSERT( IsOpened() );
 597
 598 #ifdef __WXWINCE__
 599     DWORD off0 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT);
 600     DWORD off1 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_END);
 601     if (off0 == off1)
 602         return TRUE;
 603     else
 604     {
 605         SetFilePointer((HANDLE) m_fd, off0, 0, FILE_BEGIN);
 606         return FALSE;
 607     }
 608 #else
 609     int iRc;
 610
 611 #if defined(__DOS__) || defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 612     // @@ this doesn't work, of course, on unseekable file descriptors
 613     off_t ofsCur = Tell(),
 614     ofsMax = Length();
 615     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 616         iRc = -1;
 617     else
 618         iRc = ofsCur == ofsMax;
 619 #else  // Windows and "native" compiler
 620     iRc = eof(m_fd);
 621 #endif // Windows/Unix
 622
 623     switch ( iRc ) {
 624         case 1:
 625             break;
 626
 627         case 0:
 628             return FALSE;
 629
 630         case -1:
 631             wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
 632                 break;
 633
 634         default:
 635             wxFAIL_MSG(_("invalid eof() return value."));
 636     }
 637
 638     return TRUE;
 639 #endif
 640 }
 641
 642 // ============================================================================
 643 // implementation of wxTempFile
 644 // ============================================================================
 645
 646 // ----------------------------------------------------------------------------
 647 // construction
 648 // ----------------------------------------------------------------------------
 649
 650 wxTempFile::wxTempFile(const wxString& strName)
 651 {
 652     Open(strName);
 653 }
 654
 655 bool wxTempFile::Open(const wxString& strName)
 656 {
 657     // we must have an absolute filename because otherwise CreateTempFileName()
 658     // would create the temp file in $TMP (i.e. the system standard location
 659     // for the temp files) which might be on another volume/drive/mount and
 660     // wxRename()ing it later to m_strName from Commit() would then fail
 661     //
 662     // with the absolute filename, the temp file is created in the same
 663     // directory as this one which ensures that wxRename() may work later
 664     wxFileName fn(strName);
 665     if ( !fn.IsAbsolute() )
 666     {
 667         fn.Normalize(wxPATH_NORM_ABSOLUTE);
 668     }
 669
 670     m_strName = fn.GetFullPath();
 671
 672     m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);
 673
 674     if ( m_strTemp.empty() )
 675     {
 676         // CreateTempFileName() failed
 677         return FALSE;
 678     }
 679
 680 #ifdef __UNIX__
 681     // the temp file should have the same permissions as the original one
 682     mode_t mode;
 683
 684     wxStructStat st;
 685     if ( stat( (const char*) m_strName.fn_str(), &st) == 0 )
 686     {
 687         mode = st.st_mode;
 688     }
 689     else
 690     {
 691         // file probably didn't exist, just give it the default mode _using_
 692         // user's umask (new files creation should respect umask)
 693         mode_t mask = umask(0777);
 694         mode = 0666 & ~mask;
 695         umask(mask);
 696     }
 697
 698     if ( chmod( (const char*) m_strTemp.fn_str(), mode) == -1 )
 699     {
 700         wxLogSysError(_("Failed to set temporary file permissions"));
 701     }
 702 #endif // Unix
 703
 704     return TRUE;
 705 }
 706
 707 // ----------------------------------------------------------------------------
 708 // destruction
 709 // ----------------------------------------------------------------------------
 710
 711 wxTempFile::~wxTempFile()
 712 {
 713     if ( IsOpened() )
 714         Discard();
 715 }
 716
 717 bool wxTempFile::Commit()
 718 {
 719     m_file.Close();
 720
 721     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 722         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 723         return FALSE;
 724     }
 725
 726     if ( !wxRenameFile(m_strTemp, m_strName)  ) {
 727         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 728         return FALSE;
 729     }
 730
 731     return TRUE;
 732 }
 733
 734 void wxTempFile::Discard()
 735 {
 736     m_file.Close();
 737     if ( wxRemove(m_strTemp) != 0 )
 738         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 739 }
 740
 741 #endif // wxUSE_FILE
 742