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 license
  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(__WXWINE__)
  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     #include  <windows.h>     // for GetTempFileName
  58 #elif (defined(__UNIX__) || defined(__GNUWIN32__))
  59     #include  <unistd.h>
  60     #ifdef __GNUWIN32__
  61         #include <windows.h>
  62     #endif
  63 #elif (defined(__WXPM__))
  64     #include <io.h>
  65     #include <direct.h>
  66     #define   W_OK        2
  67     #define   R_OK        4
  68 #elif (defined(__WXSTUBS__))
  69     // Have to ifdef this for different environments
  70     #include <io.h>
  71 #elif (defined(__WXMAC__))
  72     int access( const char *path, int mode ) { return 0 ; }
  73     char* mktemp( char * path ) { return path ;}
  74     #include  <unistd.h>
  75     #include  <unix.h>
  76     #define   W_OK        2
  77     #define   R_OK        4
  78 #else
  79     #error  "Please specify the header with file functions declarations."
  80 #endif  //Win/UNIX
  81
  82 #include  <stdio.h>       // SEEK_xxx constants
  83 #include  <fcntl.h>       // O_RDONLY &c
  84
  85 #ifndef __MWERKS__
  86     #include  <sys/types.h>   // needed for stat
  87     #include  <sys/stat.h>    // stat
  88 #endif
  89
  90 // Microsoft compiler loves underscores, feed them to it
  91 #ifdef  __VISUALC__
  92     // functions
  93     #define   open        _open
  94     #define   close       _close
  95     #define   read        _read
  96     #define   write       _write
  97     #define   lseek       _lseek
  98     #define   fsync       _commit
  99     #define   access      _access
 100     #define   eof         _eof
 101
 102     // types
 103     #define   stat        _stat
 104
 105     // constants
 106
 107     #define   O_RDONLY    _O_RDONLY
 108     #define   O_WRONLY    _O_WRONLY
 109     #define   O_RDWR      _O_RDWR
 110     #define   O_EXCL      _O_EXCL
 111     #define   O_CREAT     _O_CREAT
 112     #define   O_BINARY    _O_BINARY
 113
 114     #define   S_IFDIR     _S_IFDIR
 115     #define   S_IFREG     _S_IFREG
 116 #else
 117     #define   tell(fd)    lseek(fd, 0, SEEK_CUR)
 118 #endif  // VC++
 119
 120 #if defined(__BORLANDC__) || defined(_MSC_VER)
 121     #define   W_OK        2
 122     #define   R_OK        4
 123 #endif
 124
 125 // there is no distinction between text and binary files under Unix, so define
 126 // O_BINARY as 0 if the system headers don't do it already
 127 #if defined(__UNIX__) && !defined(O_BINARY)
 128     #define   O_BINARY    (0)
 129 #endif  //__UNIX__
 130
 131 #ifdef __SALFORDC__
 132     #include <unix.h>
 133 #endif
 134
 135 // wxWindows
 136 #include  "wx/string.h"
 137 #include  "wx/intl.h"
 138 #include  "wx/file.h"
 139 #include  "wx/log.h"
 140
 141 #ifndef MAX_PATH
 142     #define MAX_PATH 512
 143 #endif
 144
 145 // some broken compilers don't have 3rd argument in open() and creat()
 146 #ifdef __SALFORDC__
 147     #define ACCESS(access)
 148     #define stat    _stat
 149 #else // normal compiler
 150     #define ACCESS(access)  , (access)
 151 #endif // Salford C
 152
 153 // ============================================================================
 154 // implementation of wxFile
 155 // ============================================================================
 156
 157 // ----------------------------------------------------------------------------
 158 // static functions
 159 // ----------------------------------------------------------------------------
 160 bool wxFile::Exists(const wxChar *name)
 161 {
 162     struct stat st;
 163 #if wxUSE_UNICODE && wxMBFILES
 164     wxCharBuffer fname = wxConvFile.cWC2MB(name);
 165
 166 #ifdef __WXMAC__
 167   return !access(wxUnix2MacFilename( name ) , 0) && !stat(wxUnix2MacFilename( name ), &st) && (st.st_mode & S_IFREG);
 168 #else
 169     return !access(fname, 0) &&
 170            !stat(wxMBSTRINGCAST fname, &st) &&
 171            (st.st_mode & S_IFREG);
 172 #endif
 173 #else
 174 #ifdef __WXMAC__
 175   return !access(wxUnix2MacFilename( name ) , 0) && !stat(wxUnix2MacFilename( name ), &st) && (st.st_mode & S_IFREG);
 176 #else
 177     return !access(name, 0) &&
 178            !stat((wxChar*) name, &st) &&
 179            (st.st_mode & S_IFREG);
 180 #endif
 181 #endif
 182 }
 183
 184 bool wxFile::Access(const wxChar *name, OpenMode mode)
 185 {
 186     int how = 0;
 187
 188     switch ( mode ) {
 189         case read:
 190             how = R_OK;
 191             break;
 192
 193         case write:
 194             how = W_OK;
 195             break;
 196
 197         default:
 198             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 199     }
 200
 201     return access(wxFNCONV(name), how) == 0;
 202 }
 203
 204 // ----------------------------------------------------------------------------
 205 // opening/closing
 206 // ----------------------------------------------------------------------------
 207
 208 // ctors
 209 wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
 210 {
 211     m_fd = fd_invalid;
 212     m_error = FALSE;
 213
 214     Open(szFileName, mode);
 215 }
 216
 217 // create the file, fail if it already exists and bOverwrite
 218 bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
 219 {
 220     // if bOverwrite we create a new file or truncate the existing one,
 221     // otherwise we only create the new file and fail if it already exists
 222 #ifdef __WXMAC__
 223     int fd = open(wxUnix2MacFilename( szFileName ), O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 224 #else
 225     int fd = open(wxFNCONV(szFileName),
 226                   O_BINARY | O_WRONLY | O_CREAT |
 227                   (bOverwrite ? O_TRUNC : O_EXCL)
 228                   ACCESS(accessMode));
 229 #endif
 230     if ( fd == -1 ) {
 231         wxLogSysError(_("can't create file '%s'"), szFileName);
 232         return FALSE;
 233     }
 234     else {
 235         Attach(fd);
 236         return TRUE;
 237     }
 238 }
 239
 240 // open the file
 241 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 242 {
 243     int flags = O_BINARY;
 244
 245     switch ( mode ) {
 246         case read:
 247             flags |= O_RDONLY;
 248             break;
 249
 250         case write:
 251             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 252             break;
 253
 254         case write_append:
 255             flags |= O_WRONLY | O_APPEND;
 256             break;
 257
 258         case read_write:
 259             flags |= O_RDWR;
 260             break;
 261     }
 262
 263 #ifdef __WXMAC__
 264     int fd = open(wxUnix2MacFilename( szFileName ), flags, access);
 265 #else
 266     int fd = open(wxFNCONV(szFileName), flags ACCESS(accessMode));
 267 #endif
 268     if ( fd == -1 ) {
 269         wxLogSysError(_("can't open file '%s'"), szFileName);
 270         return FALSE;
 271     }
 272     else {
 273         Attach(fd);
 274         return TRUE;
 275     }
 276 }
 277
 278 // close
 279 bool wxFile::Close()
 280 {
 281     if ( IsOpened() ) {
 282         if ( close(m_fd) == -1 ) {
 283             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 284             m_fd = fd_invalid;
 285             return FALSE;
 286         }
 287         else
 288             m_fd = fd_invalid;
 289     }
 290
 291     return TRUE;
 292 }
 293
 294 // ----------------------------------------------------------------------------
 295 // read/write
 296 // ----------------------------------------------------------------------------
 297
 298 // read
 299 off_t wxFile::Read(void *pBuf, off_t nCount)
 300 {
 301     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 302
 303 #ifdef __MWERKS__
 304     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 305 #else
 306     int iRc = ::read(m_fd, pBuf, nCount);
 307 #endif
 308     if ( iRc == -1 ) {
 309         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 310         return wxInvalidOffset;
 311     }
 312     else
 313         return (size_t)iRc;
 314 }
 315
 316 // write
 317 size_t wxFile::Write(const void *pBuf, size_t nCount)
 318 {
 319     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 320
 321 #ifdef __MWERKS__
 322     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 323 #else
 324     int iRc = ::write(m_fd, pBuf, nCount);
 325 #endif
 326     if ( iRc == -1 ) {
 327         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 328         m_error = TRUE;
 329         return 0;
 330     }
 331     else
 332         return iRc;
 333 }
 334
 335 // flush
 336 bool wxFile::Flush()
 337 {
 338     if ( IsOpened() ) {
 339 #if defined(__VISUALC__) || wxHAVE_FSYNC
 340         if ( fsync(m_fd) == -1 )
 341         {
 342             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 343             return FALSE;
 344         }
 345 #else // no fsync
 346         // just do nothing
 347 #endif // fsync
 348     }
 349
 350     return TRUE;
 351 }
 352
 353 // ----------------------------------------------------------------------------
 354 // seek
 355 // ----------------------------------------------------------------------------
 356
 357 // seek
 358 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 359 {
 360     wxASSERT( IsOpened() );
 361
 362     int origin;
 363     switch ( mode ) {
 364         default:
 365             wxFAIL_MSG(_("unknown seek origin"));
 366
 367         case wxFromStart:
 368             origin = SEEK_SET;
 369             break;
 370
 371         case wxFromCurrent:
 372             origin = SEEK_CUR;
 373             break;
 374
 375         case wxFromEnd:
 376             origin = SEEK_END;
 377             break;
 378     }
 379
 380     int iRc = lseek(m_fd, ofs, origin);
 381     if ( iRc == -1 ) {
 382         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 383         return wxInvalidOffset;
 384     }
 385     else
 386         return (off_t)iRc;
 387 }
 388
 389 // get current off_t
 390 off_t wxFile::Tell() const
 391 {
 392     wxASSERT( IsOpened() );
 393
 394     int iRc = tell(m_fd);
 395     if ( iRc == -1 ) {
 396         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 397         return wxInvalidOffset;
 398     }
 399     else
 400         return (off_t)iRc;
 401 }
 402
 403 // get current file length
 404 off_t wxFile::Length() const
 405 {
 406     wxASSERT( IsOpened() );
 407
 408 #ifdef __VISUALC__
 409     int iRc = _filelength(m_fd);
 410 #else // !VC++
 411     int iRc = tell(m_fd);
 412     if ( iRc != -1 ) {
 413         // @ have to use const_cast :-(
 414         int iLen = ((wxFile *)this)->SeekEnd();
 415         if ( iLen != -1 ) {
 416             // restore old position
 417             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 418                 // error
 419                 iLen = -1;
 420             }
 421         }
 422
 423         iRc = iLen;
 424     }
 425 #endif  // VC++
 426
 427     if ( iRc == -1 ) {
 428         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 429         return wxInvalidOffset;
 430     }
 431     else
 432         return (off_t)iRc;
 433 }
 434
 435 // is end of file reached?
 436 bool wxFile::Eof() const
 437 {
 438     wxASSERT( IsOpened() );
 439
 440     int iRc;
 441
 442 #if defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 443     // @@ this doesn't work, of course, on unseekable file descriptors
 444     off_t ofsCur = Tell(),
 445     ofsMax = Length();
 446     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 447         iRc = -1;
 448     else
 449         iRc = ofsCur == ofsMax;
 450 #else  // Windows and "native" compiler
 451     iRc = eof(m_fd);
 452 #endif // Windows/Unix
 453
 454     switch ( iRc ) {
 455         case 1:
 456             break;
 457
 458         case 0:
 459             return FALSE;
 460
 461         case -1:
 462             wxLogSysError(_("can't determine if the end of file is reached on \
 463                 descriptor %d"), m_fd);
 464                 break;
 465
 466         default:
 467             wxFAIL_MSG(_("invalid eof() return value."));
 468     }
 469
 470     return TRUE;
 471 }
 472
 473 // ============================================================================
 474 // implementation of wxTempFile
 475 // ============================================================================
 476
 477 // ----------------------------------------------------------------------------
 478 // construction
 479 // ----------------------------------------------------------------------------
 480 wxTempFile::wxTempFile(const wxString& strName)
 481 {
 482     Open(strName);
 483 }
 484
 485 bool wxTempFile::Open(const wxString& strName)
 486 {
 487     m_strName = strName;
 488
 489     // we want to create the file in the same directory as strName because
 490     // otherwise rename() in Commit() might not work (if the files are on
 491     // different partitions for example). Unfortunately, the only standard
 492     // (POSIX) temp file creation function tmpnam() can't do it.
 493 #if defined(__UNIX__) || defined(__WXSTUBS__)|| defined( __WXMAC__ )
 494     static const wxChar *szMktempSuffix = wxT("XXXXXX");
 495     m_strTemp << strName << szMktempSuffix;
 496     // can use the cast because length doesn't change
 497     mktemp(wxMBSTRINGCAST m_strTemp.mb_str());
 498 #elif  defined(__WXPM__)
 499     // for now just create a file
 500     // future enhancements can be to set some extended attributes for file systems
 501     // OS/2 supports that have them (HPFS, FAT32) and security (HPFS386)
 502     static const wxChar *szMktempSuffix = wxT("XXX");
 503     m_strTemp << strName << szMktempSuffix;
 504     mkdir(m_strTemp.GetWriteBuf(MAX_PATH));
 505 #else // Windows
 506     wxString strPath;
 507     wxSplitPath(strName, &strPath, NULL, NULL);
 508     if ( strPath.IsEmpty() )
 509         strPath = wxT('.');  // GetTempFileName will fail if we give it empty string
 510 #ifdef __WIN32__
 511     if ( !GetTempFileName(strPath, wxT("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 512 #else
 513         // Not sure why MSVC++ 1.5 header defines first param as BYTE - bug?
 514         if ( !GetTempFileName((BYTE) (DWORD)(const wxChar*) strPath, wxT("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 515 #endif
 516             wxLogLastError(wxT("GetTempFileName"));
 517     m_strTemp.UngetWriteBuf();
 518 #endif  // Windows/Unix
 519
 520     int access = wxS_DEFAULT;
 521 #ifdef __UNIX__
 522     // create the file with the same mode as the original one under Unix
 523     mode_t umaskOld = 0; // just to suppress compiler warning
 524     bool changedUmask;
 525
 526     struct stat st;
 527     if ( stat(strName.fn_str(), &st) == 0 )
 528     {
 529         // this assumes that only lower bits of st_mode contain the access
 530         // rights, but it's true for at least all Unices which have S_IXXXX()
 531         // macros, so should not be less portable than using (not POSIX)
 532         // S_IFREG &c
 533         access = st.st_mode & 0777;
 534
 535         // we want to create the file with exactly the same access rights as
 536         // the original one, so disable the user's umask for the moment
 537         umaskOld = umask(0);
 538         changedUmask = TRUE;
 539     }
 540     else
 541     {
 542         // file probably didn't exist, just create with default mode _using_
 543         // user's umask (new files creation should respet umask)
 544         changedUmask = FALSE;
 545     }
 546 #endif // Unix
 547
 548     bool ok = m_file.Open(m_strTemp, wxFile::write, access);
 549
 550 #ifdef __UNIX__
 551     if ( changedUmask )
 552     {
 553         // restore umask now that the file is created
 554         (void)umask(umaskOld);
 555     }
 556 #endif // Unix
 557
 558     return ok;
 559 }
 560
 561 // ----------------------------------------------------------------------------
 562 // destruction
 563 // ----------------------------------------------------------------------------
 564
 565 wxTempFile::~wxTempFile()
 566 {
 567     if ( IsOpened() )
 568         Discard();
 569 }
 570
 571 bool wxTempFile::Commit()
 572 {
 573     m_file.Close();
 574
 575 #ifndef __WXMAC__
 576     if ( wxFile::Exists(m_strName) && remove(m_strName.fn_str()) != 0 ) {
 577         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 578         return FALSE;
 579     }
 580
 581     if ( rename(m_strTemp.fn_str(), m_strName.fn_str()) != 0 ) {
 582         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 583         return FALSE;
 584     }
 585 #else
 586   if ( wxFile::Exists(m_strName) && remove(wxUnix2MacFilename( m_strName )) != 0 ) {
 587     wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 588     return FALSE;
 589   }
 590
 591   if ( rename(wxUnix2MacFilename( m_strTemp ), wxUnix2MacFilename( m_strName )) != 0 ) {
 592     wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 593     return FALSE;
 594   }
 595 #endif
 596
 597     return TRUE;
 598 }
 599
 600 void wxTempFile::Discard()
 601 {
 602     m_file.Close();
 603 #ifndef __WXMAC__
 604     if ( remove(m_strTemp.fn_str()) != 0 )
 605         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 606 #else
 607     if ( remove( wxUnix2MacFilename(m_strTemp.fn_str())) != 0 )
 608         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 609 #endif
 610 }
 611
 612 #endif
 613