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__) && !defined(__WXMICROWIN__)
  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(__UNIX__) || defined(__GNUWIN32__))
  58     #include  <unistd.h>
  59     #ifdef __GNUWIN32__
  60         #include <windows.h>
  61     #endif
  62 #elif defined(__DOS__)
  63     #if defined(__WATCOMC__)
  64        #include <io.h>
  65     #elif defined(__DJGPP__)
  66        #include <io.h>
  67        #include <unistd.h>
  68        #include <stdio.h>
  69     #else
  70         #error  "Please specify the header with file functions declarations."
  71     #endif
  72 #elif (defined(__WXPM__))
  73     #include <io.h>
  74     #define   W_OK        2
  75     #define   R_OK        4
  76 #elif (defined(__WXSTUBS__))
  77     // Have to ifdef this for different environments
  78     #include <io.h>
  79 #elif (defined(__WXMAC__))
  80 #if __MSL__ < 0x6000
  81     int access( const char *path, int mode ) { return 0 ; }
  82 #else
  83     int _access( const char *path, int mode ) { return 0 ; }
  84 #endif
  85     char* mktemp( char * path ) { return path ;}
  86     #include <stat.h>
  87     #define   W_OK        2
  88     #define   R_OK        4
  89     #include  <unistd.h>
  90 #else
  91     #error  "Please specify the header with file functions declarations."
  92 #endif  //Win/UNIX
  93
  94 #include  <stdio.h>       // SEEK_xxx constants
  95 #include  <fcntl.h>       // O_RDONLY &c
  96
  97 #ifndef __MWERKS__
  98     #include  <sys/types.h>   // needed for stat
  99     #include  <sys/stat.h>    // stat
 100 #elif ( defined(__MWERKS__) && defined(__WXMSW__) )
 101     #include  <sys/types.h>   // needed for stat
 102     #include  <sys/stat.h>    // stat
 103 #endif
 104
 105 #if defined(__BORLANDC__) || defined(_MSC_VER)
 106     #define   W_OK        2
 107     #define   R_OK        4
 108 #endif
 109
 110 // there is no distinction between text and binary files under Unix, so define
 111 // O_BINARY as 0 if the system headers don't do it already
 112 #if defined(__UNIX__) && !defined(O_BINARY)
 113     #define   O_BINARY    (0)
 114 #endif  //__UNIX__
 115
 116 #ifdef __SALFORDC__
 117     #include <unix.h>
 118 #endif
 119
 120 #ifndef MAX_PATH
 121     #define MAX_PATH 512
 122 #endif
 123
 124 // some broken compilers don't have 3rd argument in open() and creat()
 125 #ifdef __SALFORDC__
 126     #define ACCESS(access)
 127     #define stat    _stat
 128 #else // normal compiler
 129     #define ACCESS(access)  , (access)
 130 #endif // Salford C
 131
 132 // wxWindows
 133 #ifndef WX_PRECOMP
 134     #include  "wx/string.h"
 135     #include  "wx/intl.h"
 136     #include  "wx/log.h"
 137 #endif // !WX_PRECOMP
 138
 139 #include  "wx/filename.h"
 140 #include  "wx/file.h"
 141
 142 // ============================================================================
 143 // implementation of wxFile
 144 // ============================================================================
 145
 146 // ----------------------------------------------------------------------------
 147 // static functions
 148 // ----------------------------------------------------------------------------
 149 bool wxFile::Exists(const wxChar *name)
 150 {
 151     wxStructStat st;
 152 #if wxUSE_UNICODE && wxMBFILES
 153     wxCharBuffer fname = wxConvFile.cWC2MB(name);
 154
 155     return !wxAccess(fname, 0) &&
 156            !wxStat(wxMBSTRINGCAST fname, &st) &&
 157            (st.st_mode & S_IFREG);
 158
 159 #else
 160     return !wxAccess(name, 0) &&
 161            !wxStat(name, &st) &&
 162            (st.st_mode & S_IFREG);
 163 #endif
 164 }
 165
 166 bool wxFile::Access(const wxChar *name, OpenMode mode)
 167 {
 168     int how = 0;
 169
 170     switch ( mode ) {
 171         case read:
 172             how = R_OK;
 173             break;
 174
 175         case write:
 176             how = W_OK;
 177             break;
 178
 179         default:
 180             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 181     }
 182
 183     return wxAccess(wxFNCONV(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__)
 205   // Dominic Mazzoni [dmazzoni+@cs.cmu.edu] reports that open is still broken on the mac, so we replace
 206   // int fd = open(wxUnix2MacFilename( szFileName ), O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 207   int fd = creat( szFileName , accessMode);
 208 #else
 209     int fd = wxOpen(wxFNCONV(szFileName),
 210                     O_BINARY | O_WRONLY | O_CREAT |
 211                     (bOverwrite ? O_TRUNC : O_EXCL)
 212                     ACCESS(accessMode));
 213 #endif
 214     if ( fd == -1 ) {
 215         wxLogSysError(_("can't create file '%s'"), szFileName);
 216         return FALSE;
 217     }
 218     else {
 219         Attach(fd);
 220         return TRUE;
 221     }
 222 }
 223
 224 // open the file
 225 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 226 {
 227     int flags = O_BINARY;
 228
 229     switch ( mode ) {
 230         case read:
 231             flags |= O_RDONLY;
 232             break;
 233
 234         case write_append:
 235             if ( wxFile::Exists(szFileName) )
 236             {
 237                 flags |= O_WRONLY | O_APPEND;
 238                 break;
 239             }
 240             //else: fall through as write_append is the same as write if the
 241             //      file doesn't exist
 242
 243         case write:
 244             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 245             break;
 246
 247         case write_excl:
 248             flags |= O_WRONLY | O_CREAT | O_EXCL;
 249             break;
 250
 251         case read_write:
 252             flags |= O_RDWR;
 253             break;
 254     }
 255
 256     int fd = wxOpen(wxFNCONV(szFileName), flags ACCESS(accessMode));
 257     if ( fd == -1 ) {
 258         wxLogSysError(_("can't open file '%s'"), szFileName);
 259         return FALSE;
 260     }
 261     else {
 262         Attach(fd);
 263         return TRUE;
 264     }
 265 }
 266
 267 // close
 268 bool wxFile::Close()
 269 {
 270     if ( IsOpened() ) {
 271         if ( close(m_fd) == -1 ) {
 272             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 273             m_fd = fd_invalid;
 274             return FALSE;
 275         }
 276         else
 277             m_fd = fd_invalid;
 278     }
 279
 280     return TRUE;
 281 }
 282
 283 // ----------------------------------------------------------------------------
 284 // read/write
 285 // ----------------------------------------------------------------------------
 286
 287 // read
 288 off_t wxFile::Read(void *pBuf, off_t nCount)
 289 {
 290     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 291
 292 #ifdef __MWERKS__
 293     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 294 #else
 295     int iRc = ::read(m_fd, pBuf, nCount);
 296 #endif
 297     if ( iRc == -1 ) {
 298         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 299         return wxInvalidOffset;
 300     }
 301     else
 302         return (size_t)iRc;
 303 }
 304
 305 // write
 306 size_t wxFile::Write(const void *pBuf, size_t nCount)
 307 {
 308     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 309
 310 #ifdef __MWERKS__
 311 #if __MSL__ >= 0x6000
 312     int iRc = ::write(m_fd, (void*) pBuf, nCount);
 313 #else
 314     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 315 #endif
 316 #else
 317     int iRc = ::write(m_fd, pBuf, nCount);
 318 #endif
 319     if ( iRc == -1 ) {
 320         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 321         m_error = TRUE;
 322         return 0;
 323     }
 324     else
 325         return iRc;
 326 }
 327
 328 // flush
 329 bool wxFile::Flush()
 330 {
 331     if ( IsOpened() ) {
 332 #if defined(__VISUALC__) || wxHAVE_FSYNC
 333         if ( wxFsync(m_fd) == -1 )
 334         {
 335             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 336             return FALSE;
 337         }
 338 #else // no fsync
 339         // just do nothing
 340 #endif // fsync
 341     }
 342
 343     return TRUE;
 344 }
 345
 346 // ----------------------------------------------------------------------------
 347 // seek
 348 // ----------------------------------------------------------------------------
 349
 350 // seek
 351 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 352 {
 353     wxASSERT( IsOpened() );
 354
 355     int origin;
 356     switch ( mode ) {
 357         default:
 358             wxFAIL_MSG(_("unknown seek origin"));
 359
 360         case wxFromStart:
 361             origin = SEEK_SET;
 362             break;
 363
 364         case wxFromCurrent:
 365             origin = SEEK_CUR;
 366             break;
 367
 368         case wxFromEnd:
 369             origin = SEEK_END;
 370             break;
 371     }
 372
 373     int iRc = lseek(m_fd, ofs, origin);
 374     if ( iRc == -1 ) {
 375         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 376         return wxInvalidOffset;
 377     }
 378     else
 379         return (off_t)iRc;
 380 }
 381
 382 // get current off_t
 383 off_t wxFile::Tell() const
 384 {
 385     wxASSERT( IsOpened() );
 386
 387     int iRc = wxTell(m_fd);
 388     if ( iRc == -1 ) {
 389         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 390         return wxInvalidOffset;
 391     }
 392     else
 393         return (off_t)iRc;
 394 }
 395
 396 // get current file length
 397 off_t wxFile::Length() const
 398 {
 399     wxASSERT( IsOpened() );
 400
 401 #ifdef __VISUALC__
 402     int iRc = _filelength(m_fd);
 403 #else // !VC++
 404     int iRc = wxTell(m_fd);
 405     if ( iRc != -1 ) {
 406         // @ have to use const_cast :-(
 407         int iLen = ((wxFile *)this)->SeekEnd();
 408         if ( iLen != -1 ) {
 409             // restore old position
 410             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 411                 // error
 412                 iLen = -1;
 413             }
 414         }
 415
 416         iRc = iLen;
 417     }
 418 #endif  // VC++
 419
 420     if ( iRc == -1 ) {
 421         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 422         return wxInvalidOffset;
 423     }
 424     else
 425         return (off_t)iRc;
 426 }
 427
 428 // is end of file reached?
 429 bool wxFile::Eof() const
 430 {
 431     wxASSERT( IsOpened() );
 432
 433     int iRc;
 434
 435 #if defined(__DOS__) || defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 436     // @@ this doesn't work, of course, on unseekable file descriptors
 437     off_t ofsCur = Tell(),
 438     ofsMax = Length();
 439     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 440         iRc = -1;
 441     else
 442         iRc = ofsCur == ofsMax;
 443 #else  // Windows and "native" compiler
 444     iRc = eof(m_fd);
 445 #endif // Windows/Unix
 446
 447     switch ( iRc ) {
 448         case 1:
 449             break;
 450
 451         case 0:
 452             return FALSE;
 453
 454         case -1:
 455             wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
 456                 break;
 457
 458         default:
 459             wxFAIL_MSG(_("invalid eof() return value."));
 460     }
 461
 462     return TRUE;
 463 }
 464
 465 // ============================================================================
 466 // implementation of wxTempFile
 467 // ============================================================================
 468
 469 // ----------------------------------------------------------------------------
 470 // construction
 471 // ----------------------------------------------------------------------------
 472
 473 wxTempFile::wxTempFile(const wxString& strName)
 474 {
 475     Open(strName);
 476 }
 477
 478 bool wxTempFile::Open(const wxString& strName)
 479 {
 480     // we must have an absolute filename because otherwise CreateTempFileName()
 481     // would create the temp file in $TMP (i.e. the system standard location
 482     // for the temp files) which might be on another volume/drive/mount and
 483     // wxRename()ing it later to m_strName from Commit() would then fail
 484     //
 485     // with the absolute filename, the temp file is created in the same
 486     // directory as this one which ensures that wxRename() may work later
 487     wxFileName fn(strName);
 488     if ( !fn.IsAbsolute() )
 489     {
 490         fn.Normalize(wxPATH_NORM_ABSOLUTE);
 491     }
 492
 493     m_strName = fn.GetFullPath();
 494
 495     m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);
 496
 497     if ( m_strTemp.empty() )
 498     {
 499         // CreateTempFileName() failed
 500         return FALSE;
 501     }
 502
 503 #ifdef __UNIX__
 504     // the temp file should have the same permissions as the original one
 505     mode_t mode;
 506
 507     wxStructStat st;
 508     if ( stat(m_strName.fn_str(), &st) == 0 )
 509     {
 510         mode = st.st_mode;
 511     }
 512     else
 513     {
 514         // file probably didn't exist, just give it the default mode _using_
 515         // user's umask (new files creation should respect umask)
 516         mode_t mask = umask(0777);
 517         mode = 0666 & ~mask;
 518         umask(mask);
 519     }
 520
 521     if ( chmod(m_strTemp.mb_str(), mode) == -1 )
 522     {
 523         wxLogSysError(_("Failed to set temporary file permissions"));
 524     }
 525 #endif // Unix
 526
 527     return TRUE;
 528 }
 529
 530 // ----------------------------------------------------------------------------
 531 // destruction
 532 // ----------------------------------------------------------------------------
 533
 534 wxTempFile::~wxTempFile()
 535 {
 536     if ( IsOpened() )
 537         Discard();
 538 }
 539
 540 bool wxTempFile::Commit()
 541 {
 542     m_file.Close();
 543
 544     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 545         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 546         return FALSE;
 547     }
 548
 549     if ( wxRename(m_strTemp, m_strName) != 0 ) {
 550         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 551         return FALSE;
 552     }
 553
 554     return TRUE;
 555 }
 556
 557 void wxTempFile::Discard()
 558 {
 559     m_file.Close();
 560     if ( wxRemove(m_strTemp) != 0 )
 561         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 562 }
 563
 564 #endif // wxUSE_FILE
 565