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_WRONLY | O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL)
 227                   ACCESS(accessMode));
 228 #endif
 229     if ( fd == -1 ) {
 230         wxLogSysError(_("can't create file '%s'"), szFileName);
 231         return FALSE;
 232     }
 233     else {
 234         Attach(fd);
 235         return TRUE;
 236     }
 237 }
 238
 239 // open the file
 240 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 241 {
 242     int flags = O_BINARY;
 243
 244     switch ( mode ) {
 245         case read:
 246             flags |= O_RDONLY;
 247             break;
 248
 249         case write:
 250             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 251             break;
 252
 253         case write_append:
 254             flags |= O_WRONLY | O_APPEND;
 255             break;
 256
 257         case read_write:
 258             flags |= O_RDWR;
 259             break;
 260     }
 261
 262 #ifdef __WXMAC__
 263   int fd = open(wxUnix2MacFilename( szFileName ), flags, access);
 264 #else
 265     int fd = open(wxFNCONV(szFileName), flags ACCESS(accessMode));
 266 #endif
 267     if ( fd == -1 ) {
 268         wxLogSysError(_("can't open file '%s'"), szFileName);
 269         return FALSE;
 270     }
 271     else {
 272         Attach(fd);
 273         return TRUE;
 274     }
 275 }
 276
 277 // close
 278 bool wxFile::Close()
 279 {
 280     if ( IsOpened() ) {
 281         if ( close(m_fd) == -1 ) {
 282             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 283             m_fd = fd_invalid;
 284             return FALSE;
 285         }
 286         else
 287             m_fd = fd_invalid;
 288     }
 289
 290     return TRUE;
 291 }
 292
 293 // ----------------------------------------------------------------------------
 294 // read/write
 295 // ----------------------------------------------------------------------------
 296
 297 // read
 298 off_t wxFile::Read(void *pBuf, off_t nCount)
 299 {
 300     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 301
 302 #ifdef __MWERKS__
 303     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 304 #else
 305     int iRc = ::read(m_fd, pBuf, nCount);
 306 #endif
 307     if ( iRc == -1 ) {
 308         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 309         return 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 #ifdef __MWERKS__
 321     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 322 #else
 323     int iRc = ::write(m_fd, pBuf, nCount);
 324 #endif
 325     if ( iRc == -1 ) {
 326         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 327         m_error = TRUE;
 328         return 0;
 329     }
 330     else
 331         return iRc;
 332 }
 333
 334 // flush
 335 bool wxFile::Flush()
 336 {
 337     if ( IsOpened() ) {
 338 #if defined(__VISUALC__) || wxHAVE_FSYNC
 339         if ( fsync(m_fd) == -1 )
 340         {
 341             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 342             return FALSE;
 343         }
 344 #else // no fsync
 345         // just do nothing
 346 #endif // fsync
 347     }
 348
 349     return TRUE;
 350 }
 351
 352 // ----------------------------------------------------------------------------
 353 // seek
 354 // ----------------------------------------------------------------------------
 355
 356 // seek
 357 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 358 {
 359     wxASSERT( IsOpened() );
 360
 361     int origin;
 362     switch ( mode ) {
 363         default:
 364             wxFAIL_MSG(_("unknown seek origin"));
 365
 366         case wxFromStart:
 367             origin = SEEK_SET;
 368             break;
 369
 370         case wxFromCurrent:
 371             origin = SEEK_CUR;
 372             break;
 373
 374         case wxFromEnd:
 375             origin = SEEK_END;
 376             break;
 377     }
 378
 379     int iRc = lseek(m_fd, ofs, origin);
 380     if ( iRc == -1 ) {
 381         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 382         return wxInvalidOffset;
 383     }
 384     else
 385         return (off_t)iRc;
 386 }
 387
 388 // get current off_t
 389 off_t wxFile::Tell() const
 390 {
 391     wxASSERT( IsOpened() );
 392
 393     int iRc = tell(m_fd);
 394     if ( iRc == -1 ) {
 395         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 396         return wxInvalidOffset;
 397     }
 398     else
 399         return (off_t)iRc;
 400 }
 401
 402 // get current file length
 403 off_t wxFile::Length() const
 404 {
 405     wxASSERT( IsOpened() );
 406
 407 #ifdef __VISUALC__
 408     int iRc = _filelength(m_fd);
 409 #else // !VC++
 410     int iRc = tell(m_fd);
 411     if ( iRc != -1 ) {
 412         // @ have to use const_cast :-(
 413         int iLen = ((wxFile *)this)->SeekEnd();
 414         if ( iLen != -1 ) {
 415             // restore old position
 416             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 417                 // error
 418                 iLen = -1;
 419             }
 420         }
 421
 422         iRc = iLen;
 423     }
 424 #endif  // VC++
 425
 426     if ( iRc == -1 ) {
 427         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 428         return wxInvalidOffset;
 429     }
 430     else
 431         return (off_t)iRc;
 432 }
 433
 434 // is end of file reached?
 435 bool wxFile::Eof() const
 436 {
 437     wxASSERT( IsOpened() );
 438
 439     int iRc;
 440
 441 #if defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 442     // @@ this doesn't work, of course, on unseekable file descriptors
 443     off_t ofsCur = Tell(),
 444     ofsMax = Length();
 445     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 446         iRc = -1;
 447     else
 448         iRc = ofsCur == ofsMax;
 449 #else  // Windows and "native" compiler
 450     iRc = eof(m_fd);
 451 #endif // Windows/Unix
 452
 453     switch ( iRc ) {
 454         case 1:
 455             break;
 456
 457         case 0:
 458             return FALSE;
 459
 460         case -1:
 461             wxLogSysError(_("can't determine if the end of file is reached on \
 462                 descriptor %d"), m_fd);
 463                 break;
 464
 465         default:
 466             wxFAIL_MSG(_("invalid eof() return value."));
 467     }
 468
 469     return TRUE;
 470 }
 471
 472 // ============================================================================
 473 // implementation of wxTempFile
 474 // ============================================================================
 475
 476 // ----------------------------------------------------------------------------
 477 // construction
 478 // ----------------------------------------------------------------------------
 479 wxTempFile::wxTempFile(const wxString& strName)
 480 {
 481     Open(strName);
 482 }
 483
 484 bool wxTempFile::Open(const wxString& strName)
 485 {
 486     m_strName = strName;
 487
 488     // we want to create the file in the same directory as strName because
 489     // otherwise rename() in Commit() might not work (if the files are on
 490     // different partitions for example). Unfortunately, the only standard
 491     // (POSIX) temp file creation function tmpnam() can't do it.
 492 #if defined(__UNIX__) || defined(__WXSTUBS__)|| defined( __WXMAC__ )
 493     static const wxChar *szMktempSuffix = wxT("XXXXXX");
 494     m_strTemp << strName << szMktempSuffix;
 495     // can use the cast because length doesn't change
 496     mktemp(wxMBSTRINGCAST m_strTemp.mb_str());
 497 #elif  defined(__WXPM__)
 498     // for now just create a file
 499     // future enhancements can be to set some extended attributes for file systems
 500     // OS/2 supports that have them (HPFS, FAT32) and security (HPFS386)
 501     static const wxChar *szMktempSuffix = wxT("XXX");
 502     m_strTemp << strName << szMktempSuffix;
 503     mkdir(m_strTemp.GetWriteBuf(MAX_PATH));
 504 #else // Windows
 505     wxString strPath;
 506     wxSplitPath(strName, &strPath, NULL, NULL);
 507     if ( strPath.IsEmpty() )
 508         strPath = wxT('.');  // GetTempFileName will fail if we give it empty string
 509 #ifdef __WIN32__
 510     if ( !GetTempFileName(strPath, wxT("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 511 #else
 512         // Not sure why MSVC++ 1.5 header defines first param as BYTE - bug?
 513         if ( !GetTempFileName((BYTE) (DWORD)(const wxChar*) strPath, wxT("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 514 #endif
 515             wxLogLastError(wxT("GetTempFileName"));
 516     m_strTemp.UngetWriteBuf();
 517 #endif  // Windows/Unix
 518
 519     int access = wxS_DEFAULT;
 520 #ifdef __UNIX__
 521     // create the file with the same mode as the original one under Unix
 522     mode_t umaskOld = 0; // just to suppress compiler warning
 523     bool changedUmask;
 524
 525     struct stat st;
 526     if ( stat(strName.fn_str(), &st) == 0 )
 527     {
 528         // this assumes that only lower bits of st_mode contain the access
 529         // rights, but it's true for at least all Unices which have S_IXXXX()
 530         // macros, so should not be less portable than using (not POSIX)
 531         // S_IFREG &c
 532         access = st.st_mode & 0777;
 533
 534         // we want to create the file with exactly the same access rights as
 535         // the original one, so disable the user's umask for the moment
 536         umaskOld = umask(0);
 537         changedUmask = TRUE;
 538     }
 539     else
 540     {
 541         // file probably didn't exist, just create with default mode _using_
 542         // user's umask (new files creation should respet umask)
 543         changedUmask = FALSE;
 544     }
 545 #endif // Unix
 546
 547     bool ok = m_file.Open(m_strTemp, wxFile::write, access);
 548
 549 #ifdef __UNIX__
 550     if ( changedUmask )
 551     {
 552         // restore umask now that the file is created
 553         (void)umask(umaskOld);
 554     }
 555 #endif // Unix
 556
 557     return ok;
 558 }
 559
 560 // ----------------------------------------------------------------------------
 561 // destruction
 562 // ----------------------------------------------------------------------------
 563
 564 wxTempFile::~wxTempFile()
 565 {
 566     if ( IsOpened() )
 567         Discard();
 568 }
 569
 570 bool wxTempFile::Commit()
 571 {
 572     m_file.Close();
 573
 574 #ifndef __WXMAC__
 575     if ( wxFile::Exists(m_strName) && remove(m_strName.fn_str()) != 0 ) {
 576         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 577         return FALSE;
 578     }
 579
 580     if ( rename(m_strTemp.fn_str(), m_strName.fn_str()) != 0 ) {
 581         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 582         return FALSE;
 583     }
 584 #else
 585   if ( wxFile::Exists(m_strName) && remove(wxUnix2MacFilename( m_strName )) != 0 ) {
 586     wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 587     return FALSE;
 588   }
 589
 590   if ( rename(wxUnix2MacFilename( m_strTemp ), wxUnix2MacFilename( m_strName )) != 0 ) {
 591     wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 592     return FALSE;
 593   }
 594 #endif
 595
 596     return TRUE;
 597 }
 598
 599 void wxTempFile::Discard()
 600 {
 601     m_file.Close();
 602 #ifndef __WXMAC__
 603     if ( remove(m_strTemp.fn_str()) != 0 )
 604         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 605 #else
 606     if ( remove( wxUnix2MacFilename(m_strTemp.fn_str())) != 0 )
 607         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 608 #endif
 609 }
 610
 611 #endif
 612