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 #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(__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     #include  <sys/stat.h>
  60     #ifdef __GNUWIN32__
  61         #include <windows.h>
  62     #endif
  63 #elif defined(__DOS__)
  64     #if defined(__WATCOMC__)
  65        #include <io.h>
  66     #elif defined(__DJGPP__)
  67        #include <io.h>
  68        #include <unistd.h>
  69        #include <stdio.h>
  70     #else
  71         #error  "Please specify the header with file functions declarations."
  72     #endif
  73 #elif (defined(__WXPM__))
  74     #include <io.h>
  75 #elif (defined(__WXSTUBS__))
  76     // Have to ifdef this for different environments
  77     #include <io.h>
  78 #elif (defined(__WXMAC__))
  79 #if __MSL__ < 0x6000
  80     int access( const char *path, int mode ) { return 0 ; }
  81 #else
  82     int _access( const char *path, int mode ) { return 0 ; }
  83 #endif
  84     char* mktemp( char * path ) { return path ;}
  85     #include <stat.h>
  86     #include  <unistd.h>
  87 #else
  88     #error  "Please specify the header with file functions declarations."
  89 #endif  //Win/UNIX
  90
  91 #include  <stdio.h>       // SEEK_xxx constants
  92 #include  <fcntl.h>       // O_RDONLY &c
  93
  94 #ifndef __MWERKS__
  95     #include  <sys/types.h>   // needed for stat
  96     #include  <sys/stat.h>    // stat
  97 #elif defined(__MWERKS__) && ( defined(__WXMSW__) || defined(__MACH__) )
  98     #include  <sys/types.h>   // needed for stat
  99     #include  <sys/stat.h>    // stat
 100 #endif
 101
 102 // Windows compilers don't have these constants
 103 #ifndef W_OK
 104     enum
 105     {
 106         F_OK = 0,   // test for existence
 107         X_OK = 1,   //          execute permission
 108         W_OK = 2,   //          write
 109         R_OK = 4    //          read
 110     };
 111 #endif // W_OK
 112
 113 // there is no distinction between text and binary files under Unix, so define
 114 // O_BINARY as 0 if the system headers don't do it already
 115 #if defined(__UNIX__) && !defined(O_BINARY)
 116     #define   O_BINARY    (0)
 117 #endif  //__UNIX__
 118
 119 #ifdef __SALFORDC__
 120     #include <unix.h>
 121 #endif
 122
 123 #ifndef MAX_PATH
 124     #define MAX_PATH 512
 125 #endif
 126
 127 // some broken compilers don't have 3rd argument in open() and creat()
 128 #ifdef __SALFORDC__
 129     #define ACCESS(access)
 130     #define stat    _stat
 131 #else // normal compiler
 132     #define ACCESS(access)  , (access)
 133 #endif // Salford C
 134
 135 // wxWindows
 136 #ifndef WX_PRECOMP
 137     #include  "wx/string.h"
 138     #include  "wx/intl.h"
 139     #include  "wx/log.h"
 140 #endif // !WX_PRECOMP
 141
 142 #include  "wx/filename.h"
 143 #include  "wx/file.h"
 144 #include  "wx/filefn.h"
 145
 146 #ifdef __WXMSW__
 147     #include "wx/msw/mslu.h"
 148 #endif
 149
 150 // ============================================================================
 151 // implementation of wxFile
 152 // ============================================================================
 153
 154 // ----------------------------------------------------------------------------
 155 // static functions
 156 // ----------------------------------------------------------------------------
 157
 158 bool wxFile::Exists(const wxChar *name)
 159 {
 160     return wxFileExists(name);
 161 }
 162
 163 bool wxFile::Access(const wxChar *name, OpenMode mode)
 164 {
 165     int how;
 166
 167     switch ( mode )
 168     {
 169         default:
 170             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 171             // fall through
 172
 173         case read:
 174             how = R_OK;
 175             break;
 176
 177         case write:
 178             how = W_OK;
 179             break;
 180
 181         case read_write:
 182             how = R_OK | W_OK;
 183             break;
 184     }
 185
 186     return wxAccess(name, how) == 0;
 187 }
 188
 189 // ----------------------------------------------------------------------------
 190 // opening/closing
 191 // ----------------------------------------------------------------------------
 192
 193 // ctors
 194 wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
 195 {
 196     m_fd = fd_invalid;
 197     m_error = FALSE;
 198
 199     Open(szFileName, mode);
 200 }
 201
 202 // create the file, fail if it already exists and bOverwrite
 203 bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
 204 {
 205     // if bOverwrite we create a new file or truncate the existing one,
 206     // otherwise we only create the new file and fail if it already exists
 207 #if defined(__WXMAC__) && !defined(__UNIX__) && !wxUSE_UNICODE
 208     // Dominic Mazzoni [dmazzoni+@cs.cmu.edu] reports that open is still broken on the mac, so we replace
 209     // int fd = open(wxUnix2MacFilename( szFileName ), O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 210     int fd = creat( szFileName , accessMode);
 211 #else
 212     int fd = wxOpen( szFileName,
 213                      O_BINARY | O_WRONLY | O_CREAT |
 214                      (bOverwrite ? O_TRUNC : O_EXCL)
 215                      ACCESS(accessMode) );
 216 #endif
 217     if ( fd == -1 )
 218     {
 219         wxLogSysError(_("can't create file '%s'"), szFileName);
 220         return FALSE;
 221     }
 222     else
 223     {
 224         Attach(fd);
 225         return TRUE;
 226     }
 227 }
 228
 229 // open the file
 230 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 231 {
 232     int flags = O_BINARY;
 233
 234     switch ( mode )
 235     {
 236         case read:
 237             flags |= O_RDONLY;
 238             break;
 239
 240         case write_append:
 241             if ( wxFile::Exists(szFileName) )
 242             {
 243                 flags |= O_WRONLY | O_APPEND;
 244                 break;
 245             }
 246             //else: fall through as write_append is the same as write if the
 247             //      file doesn't exist
 248
 249         case write:
 250             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 251             break;
 252
 253         case write_excl:
 254             flags |= O_WRONLY | O_CREAT | O_EXCL;
 255             break;
 256
 257         case read_write:
 258             flags |= O_RDWR;
 259             break;
 260     }
 261
 262     int fd = wxOpen( szFileName, flags ACCESS(accessMode));
 263     if ( fd == -1 )
 264     {
 265         wxLogSysError(_("can't open file '%s'"), szFileName);
 266         return FALSE;
 267     }
 268     else {
 269         Attach(fd);
 270         return TRUE;
 271     }
 272 }
 273
 274 // close
 275 bool wxFile::Close()
 276 {
 277     if ( IsOpened() ) {
 278         if ( close(m_fd) == -1 ) {
 279             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 280             m_fd = fd_invalid;
 281             return FALSE;
 282         }
 283         else
 284             m_fd = fd_invalid;
 285     }
 286
 287     return TRUE;
 288 }
 289
 290 // ----------------------------------------------------------------------------
 291 // read/write
 292 // ----------------------------------------------------------------------------
 293
 294 // read
 295 off_t wxFile::Read(void *pBuf, off_t nCount)
 296 {
 297     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 298
 299 #ifdef __MWERKS__
 300     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 301 #else
 302     int iRc = ::read(m_fd, pBuf, nCount);
 303 #endif
 304     if ( iRc == -1 ) {
 305         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 306         return wxInvalidOffset;
 307     }
 308     else
 309         return (size_t)iRc;
 310 }
 311
 312 // write
 313 size_t wxFile::Write(const void *pBuf, size_t nCount)
 314 {
 315     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 316
 317 #ifdef __MWERKS__
 318 #if __MSL__ >= 0x6000
 319     int iRc = ::write(m_fd, (void*) pBuf, nCount);
 320 #else
 321     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 322 #endif
 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 ( wxFsync(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 = wxTell(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 = wxTell(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(__DOS__) || 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 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
 480 wxTempFile::wxTempFile(const wxString& strName)
 481 {
 482     Open(strName);
 483 }
 484
 485 bool wxTempFile::Open(const wxString& strName)
 486 {
 487     // we must have an absolute filename because otherwise CreateTempFileName()
 488     // would create the temp file in $TMP (i.e. the system standard location
 489     // for the temp files) which might be on another volume/drive/mount and
 490     // wxRename()ing it later to m_strName from Commit() would then fail
 491     //
 492     // with the absolute filename, the temp file is created in the same
 493     // directory as this one which ensures that wxRename() may work later
 494     wxFileName fn(strName);
 495     if ( !fn.IsAbsolute() )
 496     {
 497         fn.Normalize(wxPATH_NORM_ABSOLUTE);
 498     }
 499
 500     m_strName = fn.GetFullPath();
 501
 502     m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);
 503
 504     if ( m_strTemp.empty() )
 505     {
 506         // CreateTempFileName() failed
 507         return FALSE;
 508     }
 509
 510 #ifdef __UNIX__
 511     // the temp file should have the same permissions as the original one
 512     mode_t mode;
 513
 514     wxStructStat st;
 515     if ( stat( (const char*) m_strName.fn_str(), &st) == 0 )
 516     {
 517         mode = st.st_mode;
 518     }
 519     else
 520     {
 521         // file probably didn't exist, just give it the default mode _using_
 522         // user's umask (new files creation should respect umask)
 523         mode_t mask = umask(0777);
 524         mode = 0666 & ~mask;
 525         umask(mask);
 526     }
 527
 528     if ( chmod( (const char*) m_strTemp.fn_str(), mode) == -1 )
 529     {
 530         wxLogSysError(_("Failed to set temporary file permissions"));
 531     }
 532 #endif // Unix
 533
 534     return TRUE;
 535 }
 536
 537 // ----------------------------------------------------------------------------
 538 // destruction
 539 // ----------------------------------------------------------------------------
 540
 541 wxTempFile::~wxTempFile()
 542 {
 543     if ( IsOpened() )
 544         Discard();
 545 }
 546
 547 bool wxTempFile::Commit()
 548 {
 549     m_file.Close();
 550
 551     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 552         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 553         return FALSE;
 554     }
 555
 556     if ( wxRename(m_strTemp, m_strName) != 0 ) {
 557         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 558         return FALSE;
 559     }
 560
 561     return TRUE;
 562 }
 563
 564 void wxTempFile::Discard()
 565 {
 566     m_file.Close();
 567     if ( wxRemove(m_strTemp) != 0 )
 568         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 569 }
 570
 571 #endif // wxUSE_FILE
 572