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 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  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
  33 #ifndef __SALFORDC__
  34     #define   WIN32_LEAN_AND_MEAN
  35     #define   NOSERVICE
  36     #define   NOIME
  37     #define   NOATOM
  38     #define   NOGDI
  39     #define   NOGDICAPMASKS
  40     #define   NOMETAFILE
  41     #define   NOMINMAX
  42     #define   NOMSG
  43     #define   NOOPENFILE
  44     #define   NORASTEROPS
  45     #define   NOSCROLL
  46     #define   NOSOUND
  47     #define   NOSYSMETRICS
  48     #define   NOTEXTMETRIC
  49     #define   NOWH
  50     #define   NOCOMM
  51     #define   NOKANJI
  52     #define   NOCRYPT
  53     #define   NOMCX
  54 #endif
  55
  56 #elif defined(__WXMSW__) && defined(__WXWINCE__)
  57     // TODO: what to include?
  58 #elif (defined(__OS2__))
  59     #include <io.h>
  60 #elif (defined(__UNIX__) || defined(__GNUWIN32__))
  61     #include  <unistd.h>
  62     #include  <time.h>
  63     #include  <sys/stat.h>
  64     #ifdef __GNUWIN32__
  65         #include "wx/msw/wrapwin.h"
  66     #endif
  67 #elif defined(__DOS__)
  68     #if defined(__WATCOMC__)
  69        #include <io.h>
  70     #elif defined(__DJGPP__)
  71        #include <io.h>
  72        #include <unistd.h>
  73        #include <stdio.h>
  74     #else
  75         #error  "Please specify the header with file functions declarations."
  76     #endif
  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 // Windows compilers don't have these constants
  96 #ifndef W_OK
  97     enum
  98     {
  99         F_OK = 0,   // test for existence
 100         X_OK = 1,   //          execute permission
 101         W_OK = 2,   //          write
 102         R_OK = 4    //          read
 103     };
 104 #endif // W_OK
 105
 106 // there is no distinction between text and binary files under Unix, so define
 107 // O_BINARY as 0 if the system headers don't do it already
 108 #if defined(__UNIX__) && !defined(O_BINARY)
 109     #define   O_BINARY    (0)
 110 #endif  //__UNIX__
 111
 112 #ifdef __SALFORDC__
 113     #include <unix.h>
 114 #endif
 115
 116 #ifndef MAX_PATH
 117     #define MAX_PATH 512
 118 #endif
 119
 120 // some broken compilers don't have 3rd argument in open() and creat()
 121 #ifdef __SALFORDC__
 122     #define ACCESS(access)
 123     #define stat    _stat
 124 #else // normal compiler
 125     #define ACCESS(access)  , (access)
 126 #endif // Salford C
 127
 128 // wxWidgets
 129 #ifndef WX_PRECOMP
 130     #include  "wx/string.h"
 131     #include  "wx/intl.h"
 132     #include  "wx/log.h"
 133 #endif // !WX_PRECOMP
 134
 135 #include  "wx/filename.h"
 136 #include  "wx/file.h"
 137 #include  "wx/filefn.h"
 138
 139 #ifdef __WXMSW__
 140     #include "wx/msw/mslu.h"
 141 #endif
 142
 143 #ifdef __WXWINCE__
 144     #include "wx/msw/private.h"
 145 #endif
 146
 147 // ============================================================================
 148 // implementation of wxFile
 149 // ============================================================================
 150
 151 // ----------------------------------------------------------------------------
 152 // static functions
 153 // ----------------------------------------------------------------------------
 154
 155 bool wxFile::Exists(const wxChar *name)
 156 {
 157     return wxFileExists(name);
 158 }
 159
 160 bool wxFile::Access(const wxChar *name, OpenMode mode)
 161 {
 162     int how;
 163
 164     switch ( mode )
 165     {
 166         default:
 167             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 168             // fall through
 169
 170         case read:
 171             how = R_OK;
 172             break;
 173
 174         case write:
 175             how = W_OK;
 176             break;
 177
 178         case read_write:
 179             how = R_OK | W_OK;
 180             break;
 181     }
 182
 183     return wxAccess(name, how) == 0;
 184 }
 185
 186 // ----------------------------------------------------------------------------
 187 // opening/closing
 188 // ----------------------------------------------------------------------------
 189
 190 // ctors
 191 wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
 192 {
 193     m_fd = fd_invalid;
 194     m_error = false;
 195
 196     Open(szFileName, mode);
 197 }
 198
 199 // create the file, fail if it already exists and bOverwrite
 200 bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
 201 {
 202     // if bOverwrite we create a new file or truncate the existing one,
 203     // otherwise we only create the new file and fail if it already exists
 204 #if defined(__WXMAC__) && !defined(__UNIX__) && !wxUSE_UNICODE
 205     // Dominic Mazzoni [dmazzoni+@cs.cmu.edu] reports that open is still broken on the mac, so we replace
 206     // int fd = open( szFileName , O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 207     int fd = creat( szFileName , accessMode);
 208 #else
 209     int fd = wxOpen( szFileName,
 210                      O_BINARY | O_WRONLY | O_CREAT |
 211                      (bOverwrite ? O_TRUNC : O_EXCL)
 212                      ACCESS(accessMode) );
 213 #endif
 214     if ( fd == -1 )
 215     {
 216         wxLogSysError(_("can't create file '%s'"), szFileName);
 217         return false;
 218     }
 219     else
 220     {
 221         Attach(fd);
 222         return true;
 223     }
 224 }
 225
 226 // open the file
 227 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 228 {
 229     int flags = O_BINARY;
 230
 231     switch ( mode )
 232     {
 233         case read:
 234             flags |= O_RDONLY;
 235             break;
 236
 237         case write_append:
 238             if ( wxFile::Exists(szFileName) )
 239             {
 240                 flags |= O_WRONLY | O_APPEND;
 241                 break;
 242             }
 243             //else: fall through as write_append is the same as write if the
 244             //      file doesn't exist
 245
 246         case write:
 247             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 248             break;
 249
 250         case write_excl:
 251             flags |= O_WRONLY | O_CREAT | O_EXCL;
 252             break;
 253
 254         case read_write:
 255             flags |= O_RDWR;
 256             break;
 257     }
 258
 259 #ifdef __WINDOWS__
 260     // only read/write bits for "all" are supported by this function under
 261     // Windows, and VC++ 8 returns EINVAL if any other bits are used in
 262     // accessMode, so clear them as they have at best no effect anyhow
 263     accessMode &= wxS_IRUSR | wxS_IWUSR;
 264 #endif // __WINDOWS__
 265
 266     int fd = wxOpen( szFileName, flags ACCESS(accessMode));
 267
 268     if ( fd == -1 )
 269     {
 270         wxLogSysError(_("can't open file '%s'"), szFileName);
 271         return false;
 272     }
 273     else {
 274         Attach(fd);
 275         return true;
 276     }
 277 }
 278
 279 // close
 280 bool wxFile::Close()
 281 {
 282     if ( IsOpened() ) {
 283         if (wxClose(m_fd) == -1)
 284         {
 285             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 286             m_fd = fd_invalid;
 287             return false;
 288         }
 289         else
 290             m_fd = fd_invalid;
 291     }
 292
 293     return true;
 294 }
 295
 296 // ----------------------------------------------------------------------------
 297 // read/write
 298 // ----------------------------------------------------------------------------
 299
 300 // read
 301 size_t wxFile::Read(void *pBuf, size_t nCount)
 302 {
 303     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 304
 305     int iRc = wxRead(m_fd, pBuf, nCount);
 306
 307     if ( iRc == -1 ) {
 308         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 309         return (size_t)wxInvalidOffset;
 310     }
 311     else
 312         return (size_t)iRc;
 313 }
 314
 315 // write
 316 size_t wxFile::Write(const void *pBuf, size_t nCount)
 317 {
 318     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 319
 320     int iRc = wxWrite(m_fd, pBuf, nCount);
 321
 322     if ( iRc == -1 ) {
 323         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 324         m_error = true;
 325         return 0;
 326     }
 327     else
 328         return iRc;
 329 }
 330
 331 // flush
 332 bool wxFile::Flush()
 333 {
 334     if ( IsOpened() ) {
 335 #if defined(__VISUALC__) || wxHAVE_FSYNC
 336         if ( wxFsync(m_fd) == -1 )
 337         {
 338             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 339             return false;
 340         }
 341 #else // no fsync
 342         // just do nothing
 343 #endif // fsync
 344     }
 345
 346     return true;
 347 }
 348
 349 // ----------------------------------------------------------------------------
 350 // seek
 351 // ----------------------------------------------------------------------------
 352
 353 // seek
 354 wxFileOffset wxFile::Seek(wxFileOffset ofs, wxSeekMode mode)
 355 {
 356     wxASSERT( IsOpened() );
 357
 358     int origin;
 359     switch ( mode ) {
 360         default:
 361             wxFAIL_MSG(_("unknown seek origin"));
 362
 363         case wxFromStart:
 364             origin = SEEK_SET;
 365             break;
 366
 367         case wxFromCurrent:
 368             origin = SEEK_CUR;
 369             break;
 370
 371         case wxFromEnd:
 372             origin = SEEK_END;
 373             break;
 374     }
 375
 376     if (ofs == wxInvalidOffset)
 377     {
 378         wxLogSysError(_("can't seek on file descriptor %d, large files support is not enabled."), m_fd);
 379         return wxInvalidOffset;
 380     }
 381     wxFileOffset iRc = wxSeek(m_fd, ofs, origin);
 382     if ( iRc == -1 ) {
 383         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 384         return wxInvalidOffset;
 385     }
 386     else
 387         return iRc;
 388 }
 389
 390 // get current wxFileOffset
 391 wxFileOffset wxFile::Tell() const
 392 {
 393     wxASSERT( IsOpened() );
 394
 395     wxFileOffset iRc = wxTell(m_fd);
 396     if ( iRc == -1 ) {
 397         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 398         return wxInvalidOffset;
 399     }
 400     else
 401         return iRc;
 402 }
 403
 404 // get current file length
 405 wxFileOffset wxFile::Length() const
 406 {
 407     wxASSERT( IsOpened() );
 408
 409     wxFileOffset iRc = Tell();
 410     if ( iRc != -1 ) {
 411         // @ have to use const_cast :-(
 412         wxFileOffset iLen = ((wxFile *)this)->SeekEnd();
 413         if ( iLen != -1 ) {
 414             // restore old position
 415             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 416                 // error
 417                 iLen = -1;
 418             }
 419         }
 420
 421         iRc = iLen;
 422     }
 423
 424     if ( iRc == -1 ) {
 425         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 426         return wxInvalidOffset;
 427     }
 428     else
 429         return iRc;
 430 }
 431
 432 // is end of file reached?
 433 bool wxFile::Eof() const
 434 {
 435     wxASSERT( IsOpened() );
 436
 437     int iRc;
 438
 439 #if defined(__DOS__) || defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 440     // @@ this doesn't work, of course, on unseekable file descriptors
 441     wxFileOffset ofsCur = Tell(),
 442     ofsMax = Length();
 443     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 444         iRc = -1;
 445     else
 446         iRc = ofsCur == ofsMax;
 447 #else  // Windows and "native" compiler
 448     iRc = wxEof(m_fd);
 449 #endif // Windows/Unix
 450
 451     switch ( iRc ) {
 452         case 1:
 453             break;
 454
 455         case 0:
 456             return false;
 457
 458         case -1:
 459             wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
 460                 break;
 461
 462         default:
 463             wxFAIL_MSG(_("invalid eof() return value."));
 464     }
 465
 466     return true;
 467 }
 468
 469 // ============================================================================
 470 // implementation of wxTempFile
 471 // ============================================================================
 472
 473 // ----------------------------------------------------------------------------
 474 // construction
 475 // ----------------------------------------------------------------------------
 476
 477 wxTempFile::wxTempFile(const wxString& strName)
 478 {
 479     Open(strName);
 480 }
 481
 482 bool wxTempFile::Open(const wxString& strName)
 483 {
 484     // we must have an absolute filename because otherwise CreateTempFileName()
 485     // would create the temp file in $TMP (i.e. the system standard location
 486     // for the temp files) which might be on another volume/drive/mount and
 487     // wxRename()ing it later to m_strName from Commit() would then fail
 488     //
 489     // with the absolute filename, the temp file is created in the same
 490     // directory as this one which ensures that wxRename() may work later
 491     wxFileName fn(strName);
 492     if ( !fn.IsAbsolute() )
 493     {
 494         fn.Normalize(wxPATH_NORM_ABSOLUTE);
 495     }
 496
 497     m_strName = fn.GetFullPath();
 498
 499     m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);
 500
 501     if ( m_strTemp.empty() )
 502     {
 503         // CreateTempFileName() failed
 504         return false;
 505     }
 506
 507 #ifdef __UNIX__
 508     // the temp file should have the same permissions as the original one
 509     mode_t mode;
 510
 511     wxStructStat st;
 512     if ( stat( (const char*) m_strName.fn_str(), &st) == 0 )
 513     {
 514         mode = st.st_mode;
 515     }
 516     else
 517     {
 518         // file probably didn't exist, just give it the default mode _using_
 519         // user's umask (new files creation should respect umask)
 520         mode_t mask = umask(0777);
 521         mode = 0666 & ~mask;
 522         umask(mask);
 523     }
 524
 525     if ( chmod( (const char*) m_strTemp.fn_str(), mode) == -1 )
 526     {
 527 #ifndef __OS2__
 528         wxLogSysError(_("Failed to set temporary file permissions"));
 529 #endif
 530     }
 531 #endif // Unix
 532
 533     return true;
 534 }
 535
 536 // ----------------------------------------------------------------------------
 537 // destruction
 538 // ----------------------------------------------------------------------------
 539
 540 wxTempFile::~wxTempFile()
 541 {
 542     if ( IsOpened() )
 543         Discard();
 544 }
 545
 546 bool wxTempFile::Commit()
 547 {
 548     m_file.Close();
 549
 550     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 551         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 552         return false;
 553     }
 554
 555     if ( !wxRenameFile(m_strTemp, m_strName)  ) {
 556         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 557         return false;
 558     }
 559
 560     return true;
 561 }
 562
 563 void wxTempFile::Discard()
 564 {
 565     m_file.Close();
 566     if ( wxRemove(m_strTemp) != 0 )
 567         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 568 }
 569
 570 #endif // wxUSE_FILE
 571