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 // headers
  15 // ----------------------------------------------------------------------------
  16
  17 #ifdef __GNUG__
  18     #pragma implementation "file.h"
  19 #endif
  20
  21 // For compilers that support precompilation, includes "wx.h".
  22 #include "wx/wxprec.h"
  23
  24 #ifdef __BORLANDC__
  25   #pragma hdrstop
  26 #endif
  27
  28 #if wxUSE_FILE
  29
  30 // standard
  31 #if defined(__WXMSW__) && !defined(__GNUWIN32__) && !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
  32   #include  <io.h>
  33
  34 #ifndef __SALFORDC__
  35     #define   WIN32_LEAN_AND_MEAN
  36     #define   NOSERVICE
  37     #define   NOIME
  38     #define   NOATOM
  39     #define   NOGDI
  40     #define   NOGDICAPMASKS
  41     #define   NOMETAFILE
  42     #define   NOMINMAX
  43     #define   NOMSG
  44     #define   NOOPENFILE
  45     #define   NORASTEROPS
  46     #define   NOSCROLL
  47     #define   NOSOUND
  48     #define   NOSYSMETRICS
  49     #define   NOTEXTMETRIC
  50     #define   NOWH
  51     #define   NOCOMM
  52     #define   NOKANJI
  53     #define   NOCRYPT
  54     #define   NOMCX
  55 #endif
  56
  57 #elif defined(__WXMSW__) && defined(__WXWINCE__)
  58     // TODO: what to include?
  59 #elif (defined(__UNIX__) || defined(__GNUWIN32__))
  60     #include  <unistd.h>
  61     #include  <sys/stat.h>
  62     #ifdef __GNUWIN32__
  63         #include "wx/msw/wrapwin.h"
  64     #endif
  65 #elif defined(__DOS__)
  66     #if defined(__WATCOMC__)
  67        #include <io.h>
  68     #elif defined(__DJGPP__)
  69        #include <io.h>
  70        #include <unistd.h>
  71        #include <stdio.h>
  72     #else
  73         #error  "Please specify the header with file functions declarations."
  74     #endif
  75 #elif (defined(__WXPM__))
  76     #include <io.h>
  77 #elif (defined(__WXSTUBS__))
  78     // Have to ifdef this for different environments
  79     #include <io.h>
  80 #elif (defined(__WXMAC__))
  81 #if __MSL__ < 0x6000
  82     int access( const char *path, int mode ) { return 0 ; }
  83 #else
  84     int _access( const char *path, int mode ) { return 0 ; }
  85 #endif
  86     char* mktemp( char * path ) { return path ;}
  87     #include <stat.h>
  88     #include  <unistd.h>
  89 #else
  90     #error  "Please specify the header with file functions declarations."
  91 #endif  //Win/UNIX
  92
  93 #include  <stdio.h>       // SEEK_xxx constants
  94
  95 #ifndef __WXWINCE__
  96 #include  <fcntl.h>       // O_RDONLY &c
  97 #endif
  98
  99 #ifdef __WXWINCE__
 100 // Nothing
 101 #elif !defined(__MWERKS__)
 102     #include  <sys/types.h>   // needed for stat
 103     #include  <sys/stat.h>    // stat
 104 #elif defined(__MWERKS__) && ( defined(__WXMSW__) || defined(__MACH__) )
 105     #include  <sys/types.h>   // needed for stat
 106     #include  <sys/stat.h>    // stat
 107 #endif
 108
 109 // Windows compilers don't have these constants
 110 #ifndef W_OK
 111     enum
 112     {
 113         F_OK = 0,   // test for existence
 114         X_OK = 1,   //          execute permission
 115         W_OK = 2,   //          write
 116         R_OK = 4    //          read
 117     };
 118 #endif // W_OK
 119
 120 // there is no distinction between text and binary files under Unix, so define
 121 // O_BINARY as 0 if the system headers don't do it already
 122 #if defined(__UNIX__) && !defined(O_BINARY)
 123     #define   O_BINARY    (0)
 124 #endif  //__UNIX__
 125
 126 #ifdef __SALFORDC__
 127     #include <unix.h>
 128 #endif
 129
 130 #ifndef MAX_PATH
 131     #define MAX_PATH 512
 132 #endif
 133
 134 // some broken compilers don't have 3rd argument in open() and creat()
 135 #ifdef __SALFORDC__
 136     #define ACCESS(access)
 137     #define stat    _stat
 138 #else // normal compiler
 139     #define ACCESS(access)  , (access)
 140 #endif // Salford C
 141
 142 // wxWindows
 143 #ifndef WX_PRECOMP
 144     #include  "wx/string.h"
 145     #include  "wx/intl.h"
 146     #include  "wx/log.h"
 147 #endif // !WX_PRECOMP
 148
 149 #include  "wx/filename.h"
 150 #include  "wx/file.h"
 151 #include  "wx/filefn.h"
 152
 153 #ifdef __WXMSW__
 154     #include "wx/msw/mslu.h"
 155 #endif
 156
 157 #ifdef __WXWINCE__
 158     #include "wx/msw/private.h"
 159 #endif
 160
 161 // ============================================================================
 162 // implementation of wxFile
 163 // ============================================================================
 164
 165 // ----------------------------------------------------------------------------
 166 // static functions
 167 // ----------------------------------------------------------------------------
 168
 169 bool wxFile::Exists(const wxChar *name)
 170 {
 171     return wxFileExists(name);
 172 }
 173
 174 bool wxFile::Access(const wxChar *name, OpenMode mode)
 175 {
 176     int how;
 177
 178     switch ( mode )
 179     {
 180         default:
 181             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 182             // fall through
 183
 184         case read:
 185             how = R_OK;
 186             break;
 187
 188         case write:
 189             how = W_OK;
 190             break;
 191
 192         case read_write:
 193             how = R_OK | W_OK;
 194             break;
 195     }
 196
 197 #ifdef __WXWINCE__
 198     // FIXME: use CreateFile with 0 access to query the file
 199     return TRUE;
 200 #else
 201     return wxAccess(name, how) == 0;
 202 #endif
 203 }
 204
 205 // ----------------------------------------------------------------------------
 206 // opening/closing
 207 // ----------------------------------------------------------------------------
 208
 209 // ctors
 210 wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
 211 {
 212     m_fd = fd_invalid;
 213     m_error = FALSE;
 214
 215     Open(szFileName, mode);
 216 }
 217
 218 // create the file, fail if it already exists and bOverwrite
 219 bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
 220 {
 221     // if bOverwrite we create a new file or truncate the existing one,
 222     // otherwise we only create the new file and fail if it already exists
 223 #if defined(__WXMAC__) && !defined(__UNIX__) && !wxUSE_UNICODE
 224     // Dominic Mazzoni [dmazzoni+@cs.cmu.edu] reports that open is still broken on the mac, so we replace
 225     // int fd = open(wxUnix2MacFilename( szFileName ), O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 226     int fd = creat( szFileName , accessMode);
 227 #else
 228 #ifdef __WXWINCE__
 229     HANDLE fileHandle = ::CreateFile(szFileName, GENERIC_WRITE, 0, NULL,
 230         bOverwrite ? CREATE_ALWAYS : CREATE_NEW, FILE_ATTRIBUTE_NORMAL,
 231         0);
 232     int fd = 0;
 233     if (fileHandle == INVALID_HANDLE_VALUE)
 234         fd = (int) fileHandle;
 235     else
 236         fd = -1;
 237 #else
 238     int fd = wxOpen( szFileName,
 239                      O_BINARY | O_WRONLY | O_CREAT |
 240                      (bOverwrite ? O_TRUNC : O_EXCL)
 241                      ACCESS(accessMode) );
 242 #endif
 243 #endif
 244     if ( fd == -1 )
 245     {
 246         wxLogSysError(_("can't create file '%s'"), szFileName);
 247         return FALSE;
 248     }
 249     else
 250     {
 251         Attach(fd);
 252         return TRUE;
 253     }
 254 }
 255
 256 // open the file
 257 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 258 {
 259 #ifdef __WXWINCE__
 260     DWORD access = 0;
 261     DWORD shareMode = 0;
 262     DWORD disposition = 0;
 263
 264     int flags = O_BINARY;
 265
 266     switch ( mode )
 267     {
 268         case read:
 269             access = GENERIC_READ;
 270             shareMode = FILE_SHARE_READ|FILE_SHARE_WRITE;
 271             disposition = OPEN_EXISTING;
 272             break;
 273
 274         case write_append:
 275             if ( wxFile::Exists(szFileName) )
 276             {
 277                 access = GENERIC_READ|GENERIC_WRITE;
 278                 shareMode = FILE_SHARE_READ;
 279                 disposition = 0;
 280                 break;
 281             }
 282             //else: fall through as write_append is the same as write if the
 283             //      file doesn't exist
 284
 285         case write:
 286             access = GENERIC_WRITE;
 287             shareMode = 0;
 288             disposition = TRUNCATE_EXISTING;
 289             break;
 290
 291         case write_excl:
 292             access = GENERIC_WRITE;
 293             shareMode = 0;
 294             disposition = TRUNCATE_EXISTING;
 295             break;
 296
 297         case read_write:
 298             access = GENERIC_READ|GENERIC_WRITE;
 299             shareMode = 0;
 300             disposition = 0;
 301             break;
 302     }
 303
 304     int fd = 0;
 305     HANDLE fileHandle = ::CreateFile(szFileName, access, shareMode, NULL,
 306         disposition, FILE_ATTRIBUTE_NORMAL, 0);
 307     if (fileHandle == INVALID_HANDLE_VALUE)
 308         fd = -1;
 309     else
 310         fd = (int) fileHandle;
 311 #else
 312     int flags = O_BINARY;
 313
 314     switch ( mode )
 315     {
 316         case read:
 317             flags |= O_RDONLY;
 318             break;
 319
 320         case write_append:
 321             if ( wxFile::Exists(szFileName) )
 322             {
 323                 flags |= O_WRONLY | O_APPEND;
 324                 break;
 325             }
 326             //else: fall through as write_append is the same as write if the
 327             //      file doesn't exist
 328
 329         case write:
 330             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 331             break;
 332
 333         case write_excl:
 334             flags |= O_WRONLY | O_CREAT | O_EXCL;
 335             break;
 336
 337         case read_write:
 338             flags |= O_RDWR;
 339             break;
 340     }
 341
 342     int fd = wxOpen( szFileName, flags ACCESS(accessMode));
 343 #endif
 344     if ( fd == -1 )
 345     {
 346         wxLogSysError(_("can't open file '%s'"), szFileName);
 347         return FALSE;
 348     }
 349     else {
 350         Attach(fd);
 351         return TRUE;
 352     }
 353 }
 354
 355 // close
 356 bool wxFile::Close()
 357 {
 358     if ( IsOpened() ) {
 359 #ifdef __WXWINCE__
 360         if (!CloseHandle((HANDLE) m_fd))
 361 #else
 362         if ( close(m_fd) == -1 )
 363 #endif
 364         {
 365             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 366             m_fd = fd_invalid;
 367             return FALSE;
 368         }
 369         else
 370             m_fd = fd_invalid;
 371     }
 372
 373     return TRUE;
 374 }
 375
 376 // ----------------------------------------------------------------------------
 377 // read/write
 378 // ----------------------------------------------------------------------------
 379
 380 // read
 381 off_t wxFile::Read(void *pBuf, off_t nCount)
 382 {
 383     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 384
 385 #ifdef __WXWINCE__
 386     DWORD bytesRead = 0;
 387     int iRc = 0;
 388     if (ReadFile((HANDLE) m_fd, pBuf, (DWORD) nCount, & bytesRead, NULL))
 389         iRc = bytesRead;
 390     else
 391         iRc = -1;
 392 #elif defined(__MWERKS__)
 393     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 394 #else
 395     int iRc = ::read(m_fd, pBuf, nCount);
 396 #endif
 397     if ( iRc == -1 ) {
 398         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 399         return wxInvalidOffset;
 400     }
 401     else
 402         return (size_t)iRc;
 403 }
 404
 405 // write
 406 size_t wxFile::Write(const void *pBuf, size_t nCount)
 407 {
 408     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 409
 410 #ifdef __WXWINCE__
 411     DWORD bytesRead = 0;
 412     int iRc = 0;
 413     if (WriteFile((HANDLE) m_fd, pBuf, (DWORD) nCount, & bytesRead, NULL))
 414         iRc = bytesRead;
 415     else
 416         iRc = -1;
 417 #elif defined(__MWERKS__)
 418 #if __MSL__ >= 0x6000
 419     int iRc = ::write(m_fd, (void*) pBuf, nCount);
 420 #else
 421     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 422 #endif
 423 #else
 424     int iRc = ::write(m_fd, pBuf, nCount);
 425 #endif
 426     if ( iRc == -1 ) {
 427         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 428         m_error = TRUE;
 429         return 0;
 430     }
 431     else
 432         return iRc;
 433 }
 434
 435 // flush
 436 bool wxFile::Flush()
 437 {
 438     if ( IsOpened() ) {
 439 #ifdef __WXWINCE__
 440         // Do nothing
 441 #elif defined(__VISUALC__) || wxHAVE_FSYNC
 442         if ( wxFsync(m_fd) == -1 )
 443         {
 444             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 445             return FALSE;
 446         }
 447 #else // no fsync
 448         // just do nothing
 449 #endif // fsync
 450     }
 451
 452     return TRUE;
 453 }
 454
 455 // ----------------------------------------------------------------------------
 456 // seek
 457 // ----------------------------------------------------------------------------
 458
 459 // seek
 460 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 461 {
 462     wxASSERT( IsOpened() );
 463
 464 #ifdef __WXWINCE__
 465     int origin;
 466     switch ( mode ) {
 467         default:
 468             wxFAIL_MSG(_("unknown seek origin"));
 469
 470         case wxFromStart:
 471             origin = FILE_BEGIN;
 472             break;
 473
 474         case wxFromCurrent:
 475             origin = FILE_CURRENT;
 476             break;
 477
 478         case wxFromEnd:
 479             origin = FILE_END;
 480             break;
 481     }
 482
 483     DWORD res = SetFilePointer((HANDLE) m_fd, ofs, 0, origin) ;
 484     if (res == 0xFFFFFFFF && GetLastError() != NO_ERROR)
 485     {
 486         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 487         return wxInvalidOffset;
 488     }
 489     else
 490         return (off_t)res;
 491 #else
 492     int origin;
 493     switch ( mode ) {
 494         default:
 495             wxFAIL_MSG(_("unknown seek origin"));
 496
 497         case wxFromStart:
 498             origin = SEEK_SET;
 499             break;
 500
 501         case wxFromCurrent:
 502             origin = SEEK_CUR;
 503             break;
 504
 505         case wxFromEnd:
 506             origin = SEEK_END;
 507             break;
 508     }
 509
 510     int iRc = lseek(m_fd, ofs, origin);
 511     if ( iRc == -1 ) {
 512         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 513         return wxInvalidOffset;
 514     }
 515     else
 516         return (off_t)iRc;
 517 #endif
 518 }
 519
 520 // get current off_t
 521 off_t wxFile::Tell() const
 522 {
 523     wxASSERT( IsOpened() );
 524
 525 #ifdef __WXWINCE__
 526     DWORD res = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT) ;
 527     if (res == 0xFFFFFFFF && GetLastError() != NO_ERROR)
 528     {
 529         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 530         return wxInvalidOffset;
 531     }
 532     else
 533         return (off_t)res;
 534 #else
 535     int iRc = wxTell(m_fd);
 536     if ( iRc == -1 ) {
 537         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 538         return wxInvalidOffset;
 539     }
 540     else
 541         return (off_t)iRc;
 542 #endif
 543 }
 544
 545 // get current file length
 546 off_t wxFile::Length() const
 547 {
 548     wxASSERT( IsOpened() );
 549
 550 #ifdef __WXWINCE__
 551     DWORD off0 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT);
 552     DWORD off1 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_END);
 553     off_t len = off1;
 554
 555     // Restore position
 556     SetFilePointer((HANDLE) m_fd, off0, 0, FILE_BEGIN);
 557     return len;
 558 #else
 559 #ifdef __VISUALC__
 560     int iRc = _filelength(m_fd);
 561 #else // !VC++
 562     int iRc = wxTell(m_fd);
 563     if ( iRc != -1 ) {
 564         // @ have to use const_cast :-(
 565         int iLen = ((wxFile *)this)->SeekEnd();
 566         if ( iLen != -1 ) {
 567             // restore old position
 568             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 569                 // error
 570                 iLen = -1;
 571             }
 572         }
 573
 574         iRc = iLen;
 575     }
 576 #endif  // VC++
 577
 578     if ( iRc == -1 ) {
 579         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 580         return wxInvalidOffset;
 581     }
 582     else
 583         return (off_t)iRc;
 584 #endif
 585 }
 586
 587 // is end of file reached?
 588 bool wxFile::Eof() const
 589 {
 590     wxASSERT( IsOpened() );
 591
 592 #ifdef __WXWINCE__
 593     DWORD off0 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_CURRENT);
 594     DWORD off1 = SetFilePointer((HANDLE) m_fd, 0, 0, FILE_END);
 595     if (off0 == off1)
 596         return TRUE;
 597     else
 598     {
 599         SetFilePointer((HANDLE) m_fd, off0, 0, FILE_BEGIN);
 600         return FALSE;
 601     }
 602 #else
 603     int iRc;
 604
 605 #if defined(__DOS__) || defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 606     // @@ this doesn't work, of course, on unseekable file descriptors
 607     off_t ofsCur = Tell(),
 608     ofsMax = Length();
 609     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 610         iRc = -1;
 611     else
 612         iRc = ofsCur == ofsMax;
 613 #else  // Windows and "native" compiler
 614     iRc = eof(m_fd);
 615 #endif // Windows/Unix
 616
 617     switch ( iRc ) {
 618         case 1:
 619             break;
 620
 621         case 0:
 622             return FALSE;
 623
 624         case -1:
 625             wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
 626                 break;
 627
 628         default:
 629             wxFAIL_MSG(_("invalid eof() return value."));
 630     }
 631
 632     return TRUE;
 633 #endif
 634 }
 635
 636 // ============================================================================
 637 // implementation of wxTempFile
 638 // ============================================================================
 639
 640 // ----------------------------------------------------------------------------
 641 // construction
 642 // ----------------------------------------------------------------------------
 643
 644 wxTempFile::wxTempFile(const wxString& strName)
 645 {
 646     Open(strName);
 647 }
 648
 649 bool wxTempFile::Open(const wxString& strName)
 650 {
 651     // we must have an absolute filename because otherwise CreateTempFileName()
 652     // would create the temp file in $TMP (i.e. the system standard location
 653     // for the temp files) which might be on another volume/drive/mount and
 654     // wxRename()ing it later to m_strName from Commit() would then fail
 655     //
 656     // with the absolute filename, the temp file is created in the same
 657     // directory as this one which ensures that wxRename() may work later
 658     wxFileName fn(strName);
 659     if ( !fn.IsAbsolute() )
 660     {
 661         fn.Normalize(wxPATH_NORM_ABSOLUTE);
 662     }
 663
 664     m_strName = fn.GetFullPath();
 665
 666     m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);
 667
 668     if ( m_strTemp.empty() )
 669     {
 670         // CreateTempFileName() failed
 671         return FALSE;
 672     }
 673
 674 #ifdef __UNIX__
 675     // the temp file should have the same permissions as the original one
 676     mode_t mode;
 677
 678     wxStructStat st;
 679     if ( stat( (const char*) m_strName.fn_str(), &st) == 0 )
 680     {
 681         mode = st.st_mode;
 682     }
 683     else
 684     {
 685         // file probably didn't exist, just give it the default mode _using_
 686         // user's umask (new files creation should respect umask)
 687         mode_t mask = umask(0777);
 688         mode = 0666 & ~mask;
 689         umask(mask);
 690     }
 691
 692     if ( chmod( (const char*) m_strTemp.fn_str(), mode) == -1 )
 693     {
 694         wxLogSysError(_("Failed to set temporary file permissions"));
 695     }
 696 #endif // Unix
 697
 698     return TRUE;
 699 }
 700
 701 // ----------------------------------------------------------------------------
 702 // destruction
 703 // ----------------------------------------------------------------------------
 704
 705 wxTempFile::~wxTempFile()
 706 {
 707     if ( IsOpened() )
 708         Discard();
 709 }
 710
 711 bool wxTempFile::Commit()
 712 {
 713     m_file.Close();
 714
 715     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 716         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 717         return FALSE;
 718     }
 719
 720     if ( !wxRenameFile(m_strTemp, m_strName)  ) {
 721         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 722         return FALSE;
 723     }
 724
 725     return TRUE;
 726 }
 727
 728 void wxTempFile::Discard()
 729 {
 730     m_file.Close();
 731     if ( wxRemove(m_strTemp) != 0 )
 732         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 733 }
 734
 735 #endif // wxUSE_FILE
 736