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