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 #if __MSL__ < 0x6000
  72     int access( const char *path, int mode ) { return 0 ; }
  73 #else
  74     int _access( const char *path, int mode ) { return 0 ; }
  75 #endif
  76     char* mktemp( char * path ) { return path ;}
  77     #include <stat.h>
  78     #define   W_OK        2
  79     #define   R_OK        4
  80     #include  <unistd.h>
  81 #else
  82     #error  "Please specify the header with file functions declarations."
  83 #endif  //Win/UNIX
  84
  85 #include  <stdio.h>       // SEEK_xxx constants
  86 #include  <fcntl.h>       // O_RDONLY &c
  87
  88 #ifndef __MWERKS__
  89     #include  <sys/types.h>   // needed for stat
  90     #include  <sys/stat.h>    // stat
  91 #endif
  92
  93 #if defined(__BORLANDC__) || defined(_MSC_VER)
  94     #define   W_OK        2
  95     #define   R_OK        4
  96 #endif
  97
  98 // there is no distinction between text and binary files under Unix, so define
  99 // O_BINARY as 0 if the system headers don't do it already
 100 #if defined(__UNIX__) && !defined(O_BINARY)
 101     #define   O_BINARY    (0)
 102 #endif  //__UNIX__
 103
 104 #ifdef __SALFORDC__
 105     #include <unix.h>
 106 #endif
 107
 108 #ifndef MAX_PATH
 109     #define MAX_PATH 512
 110 #endif
 111
 112 // some broken compilers don't have 3rd argument in open() and creat()
 113 #ifdef __SALFORDC__
 114     #define ACCESS(access)
 115     #define stat    _stat
 116 #else // normal compiler
 117     #define ACCESS(access)  , (access)
 118 #endif // Salford C
 119
 120 // wxWindows
 121 #include  "wx/string.h"
 122 #include  "wx/intl.h"
 123 #include  "wx/file.h"
 124 #include  "wx/log.h"
 125
 126 // ============================================================================
 127 // implementation of wxFile
 128 // ============================================================================
 129
 130 // ----------------------------------------------------------------------------
 131 // static functions
 132 // ----------------------------------------------------------------------------
 133 bool wxFile::Exists(const wxChar *name)
 134 {
 135     wxStructStat st;
 136 #if wxUSE_UNICODE && wxMBFILES
 137     wxCharBuffer fname = wxConvFile.cWC2MB(name);
 138
 139 #if defined(__WXMAC__) && !defined(__UNIX__)
 140   return !access(wxUnix2MacFilename( name ) , 0) && !stat(wxUnix2MacFilename( name ), &st) && (st.st_mode & S_IFREG);
 141 #else
 142     return !wxAccess(fname, 0) &&
 143            !wxStat(wxMBSTRINGCAST fname, &st) &&
 144            (st.st_mode & S_IFREG);
 145 #endif
 146 #else
 147 #if defined(__WXMAC__) && !defined(__UNIX__)
 148   return !access(wxUnix2MacFilename( name ) , 0) && !stat(wxUnix2MacFilename( name ), &st) && (st.st_mode & S_IFREG);
 149 #else
 150     return !wxAccess(name, 0) &&
 151            !wxStat(name, &st) &&
 152            (st.st_mode & S_IFREG);
 153 #endif
 154 #endif
 155 }
 156
 157 bool wxFile::Access(const wxChar *name, OpenMode mode)
 158 {
 159     int how = 0;
 160
 161     switch ( mode ) {
 162         case read:
 163             how = R_OK;
 164             break;
 165
 166         case write:
 167             how = W_OK;
 168             break;
 169
 170         default:
 171             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 172     }
 173
 174     return wxAccess(wxFNCONV(name), how) == 0;
 175 }
 176
 177 // ----------------------------------------------------------------------------
 178 // opening/closing
 179 // ----------------------------------------------------------------------------
 180
 181 // ctors
 182 wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
 183 {
 184     m_fd = fd_invalid;
 185     m_error = FALSE;
 186
 187     Open(szFileName, mode);
 188 }
 189
 190 // create the file, fail if it already exists and bOverwrite
 191 bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
 192 {
 193     // if bOverwrite we create a new file or truncate the existing one,
 194     // otherwise we only create the new file and fail if it already exists
 195 #if defined(__WXMAC__) && !defined(__UNIX__)
 196   // Dominic Mazzoni [dmazzoni+@cs.cmu.edu] reports that open is still broken on the mac, so we replace
 197   // int fd = open(wxUnix2MacFilename( szFileName ), O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 198   int fd = creat(wxUnix2MacFilename( szFileName ), accessMode);
 199 #else
 200     int fd = wxOpen(wxFNCONV(szFileName),
 201                     O_BINARY | O_WRONLY | O_CREAT |
 202                     (bOverwrite ? O_TRUNC : O_EXCL)
 203                     ACCESS(accessMode));
 204 #endif
 205     if ( fd == -1 ) {
 206         wxLogSysError(_("can't create file '%s'"), szFileName);
 207         return FALSE;
 208     }
 209     else {
 210         Attach(fd);
 211         return TRUE;
 212     }
 213 }
 214
 215 // open the file
 216 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 217 {
 218     int flags = O_BINARY;
 219
 220     switch ( mode ) {
 221         case read:
 222             flags |= O_RDONLY;
 223             break;
 224
 225         case write_append:
 226             if ( wxFile::Exists(szFileName) )
 227             {
 228                 flags |= O_WRONLY | O_APPEND;
 229                 break;
 230             }
 231             //else: fall through as write_append is the same as write if the
 232             //      file doesn't exist
 233
 234         case write:
 235             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 236             break;
 237
 238         case read_write:
 239             flags |= O_RDWR;
 240             break;
 241     }
 242
 243 #if defined(__WXMAC__) && !defined(__UNIX__)
 244     int fd = open(wxUnix2MacFilename( szFileName ), flags, access);
 245 #else
 246     int fd = wxOpen(wxFNCONV(szFileName), flags ACCESS(accessMode));
 247 #endif
 248     if ( fd == -1 ) {
 249         wxLogSysError(_("can't open file '%s'"), szFileName);
 250         return FALSE;
 251     }
 252     else {
 253         Attach(fd);
 254         return TRUE;
 255     }
 256 }
 257
 258 // close
 259 bool wxFile::Close()
 260 {
 261     if ( IsOpened() ) {
 262         if ( close(m_fd) == -1 ) {
 263             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 264             m_fd = fd_invalid;
 265             return FALSE;
 266         }
 267         else
 268             m_fd = fd_invalid;
 269     }
 270
 271     return TRUE;
 272 }
 273
 274 // ----------------------------------------------------------------------------
 275 // read/write
 276 // ----------------------------------------------------------------------------
 277
 278 // read
 279 off_t wxFile::Read(void *pBuf, off_t nCount)
 280 {
 281     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 282
 283 #ifdef __MWERKS__
 284     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 285 #else
 286     int iRc = ::read(m_fd, pBuf, nCount);
 287 #endif
 288     if ( iRc == -1 ) {
 289         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 290         return wxInvalidOffset;
 291     }
 292     else
 293         return (size_t)iRc;
 294 }
 295
 296 // write
 297 size_t wxFile::Write(const void *pBuf, size_t nCount)
 298 {
 299     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 300
 301 #ifdef __MWERKS__
 302 #if __MSL__ >= 0x6000
 303     int iRc = ::write(m_fd, (void*) pBuf, nCount);
 304 #else
 305     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 306 #endif
 307 #else
 308     int iRc = ::write(m_fd, pBuf, nCount);
 309 #endif
 310     if ( iRc == -1 ) {
 311         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 312         m_error = TRUE;
 313         return 0;
 314     }
 315     else
 316         return iRc;
 317 }
 318
 319 // flush
 320 bool wxFile::Flush()
 321 {
 322     if ( IsOpened() ) {
 323 #if defined(__VISUALC__) || wxHAVE_FSYNC
 324         if ( wxFsync(m_fd) == -1 )
 325         {
 326             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 327             return FALSE;
 328         }
 329 #else // no fsync
 330         // just do nothing
 331 #endif // fsync
 332     }
 333
 334     return TRUE;
 335 }
 336
 337 // ----------------------------------------------------------------------------
 338 // seek
 339 // ----------------------------------------------------------------------------
 340
 341 // seek
 342 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 343 {
 344     wxASSERT( IsOpened() );
 345
 346     int origin;
 347     switch ( mode ) {
 348         default:
 349             wxFAIL_MSG(_("unknown seek origin"));
 350
 351         case wxFromStart:
 352             origin = SEEK_SET;
 353             break;
 354
 355         case wxFromCurrent:
 356             origin = SEEK_CUR;
 357             break;
 358
 359         case wxFromEnd:
 360             origin = SEEK_END;
 361             break;
 362     }
 363
 364     int iRc = lseek(m_fd, ofs, origin);
 365     if ( iRc == -1 ) {
 366         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 367         return wxInvalidOffset;
 368     }
 369     else
 370         return (off_t)iRc;
 371 }
 372
 373 // get current off_t
 374 off_t wxFile::Tell() const
 375 {
 376     wxASSERT( IsOpened() );
 377
 378     int iRc = wxTell(m_fd);
 379     if ( iRc == -1 ) {
 380         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 381         return wxInvalidOffset;
 382     }
 383     else
 384         return (off_t)iRc;
 385 }
 386
 387 // get current file length
 388 off_t wxFile::Length() const
 389 {
 390     wxASSERT( IsOpened() );
 391
 392 #ifdef __VISUALC__
 393     int iRc = _filelength(m_fd);
 394 #else // !VC++
 395     int iRc = wxTell(m_fd);
 396     if ( iRc != -1 ) {
 397         // @ have to use const_cast :-(
 398         int iLen = ((wxFile *)this)->SeekEnd();
 399         if ( iLen != -1 ) {
 400             // restore old position
 401             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 402                 // error
 403                 iLen = -1;
 404             }
 405         }
 406
 407         iRc = iLen;
 408     }
 409 #endif  // VC++
 410
 411     if ( iRc == -1 ) {
 412         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 413         return wxInvalidOffset;
 414     }
 415     else
 416         return (off_t)iRc;
 417 }
 418
 419 // is end of file reached?
 420 bool wxFile::Eof() const
 421 {
 422     wxASSERT( IsOpened() );
 423
 424     int iRc;
 425
 426 #if defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 427     // @@ this doesn't work, of course, on unseekable file descriptors
 428     off_t ofsCur = Tell(),
 429     ofsMax = Length();
 430     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 431         iRc = -1;
 432     else
 433         iRc = ofsCur == ofsMax;
 434 #else  // Windows and "native" compiler
 435     iRc = eof(m_fd);
 436 #endif // Windows/Unix
 437
 438     switch ( iRc ) {
 439         case 1:
 440             break;
 441
 442         case 0:
 443             return FALSE;
 444
 445         case -1:
 446             wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
 447                 break;
 448
 449         default:
 450             wxFAIL_MSG(_("invalid eof() return value."));
 451     }
 452
 453     return TRUE;
 454 }
 455
 456 // ============================================================================
 457 // implementation of wxTempFile
 458 // ============================================================================
 459
 460 // ----------------------------------------------------------------------------
 461 // construction
 462 // ----------------------------------------------------------------------------
 463 wxTempFile::wxTempFile(const wxString& strName)
 464 {
 465     Open(strName);
 466 }
 467
 468 bool wxTempFile::Open(const wxString& strName)
 469 {
 470     m_strName = strName;
 471
 472     // we want to create the file in the same directory as strName because
 473     // otherwise rename() in Commit() might not work (if the files are on
 474     // different partitions for example). Unfortunately, the only standard
 475     // (POSIX) temp file creation function tmpnam() can't do it.
 476 #if defined(__UNIX__) || defined(__WXSTUBS__)|| defined( __WXMAC__ )
 477     static const wxChar *szMktempSuffix = wxT("XXXXXX");
 478     m_strTemp << strName << szMktempSuffix;
 479     // can use the cast because length doesn't change
 480     mktemp(wxMBSTRINGCAST m_strTemp.mb_str());
 481 #elif  defined(__WXPM__)
 482     // for now just create a file
 483     // future enhancements can be to set some extended attributes for file systems
 484     // OS/2 supports that have them (HPFS, FAT32) and security (HPFS386)
 485     static const wxChar *szMktempSuffix = wxT("XXX");
 486     m_strTemp << strName << szMktempSuffix;
 487     ::DosCreateDir(m_strTemp.GetWriteBuf(MAX_PATH), NULL);
 488 #else // Windows
 489     wxString strPath;
 490     wxSplitPath(strName, &strPath, NULL, NULL);
 491     if ( strPath.IsEmpty() )
 492         strPath = wxT('.');  // GetTempFileName will fail if we give it empty string
 493 #ifdef __WIN32__
 494     if ( !GetTempFileName(strPath, wxT("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 495 #else
 496         // Not sure why MSVC++ 1.5 header defines first param as BYTE - bug?
 497         if ( !GetTempFileName((BYTE) (DWORD)(const wxChar*) strPath, wxT("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 498 #endif
 499             wxLogLastError(wxT("GetTempFileName"));
 500     m_strTemp.UngetWriteBuf();
 501 #endif  // Windows/Unix
 502
 503     int access = wxS_DEFAULT;
 504 #ifdef __UNIX__
 505     // create the file with the same mode as the original one under Unix
 506     mode_t umaskOld = 0; // just to suppress compiler warning
 507     bool changedUmask;
 508
 509     wxStructStat st;
 510     if ( stat(strName.fn_str(), &st) == 0 )
 511     {
 512         // this assumes that only lower bits of st_mode contain the access
 513         // rights, but it's true for at least all Unices which have S_IXXXX()
 514         // macros, so should not be less portable than using (not POSIX)
 515         // S_IFREG &c
 516         access = st.st_mode & 0777;
 517
 518         // we want to create the file with exactly the same access rights as
 519         // the original one, so disable the user's umask for the moment
 520         umaskOld = umask(0);
 521         changedUmask = TRUE;
 522     }
 523     else
 524     {
 525         // file probably didn't exist, just create with default mode _using_
 526         // user's umask (new files creation should respet umask)
 527         changedUmask = FALSE;
 528     }
 529 #endif // Unix
 530
 531     bool ok = m_file.Open(m_strTemp, wxFile::write, access);
 532
 533 #ifdef __UNIX__
 534     if ( changedUmask )
 535     {
 536         // restore umask now that the file is created
 537         (void)umask(umaskOld);
 538     }
 539 #endif // Unix
 540
 541     return ok;
 542 }
 543
 544 // ----------------------------------------------------------------------------
 545 // destruction
 546 // ----------------------------------------------------------------------------
 547
 548 wxTempFile::~wxTempFile()
 549 {
 550     if ( IsOpened() )
 551         Discard();
 552 }
 553
 554 bool wxTempFile::Commit()
 555 {
 556     m_file.Close();
 557
 558 #if !defined(__WXMAC__) || defined(__UNIX__)
 559     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 560         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 561         return FALSE;
 562     }
 563
 564     if ( wxRename(m_strTemp, m_strName) != 0 ) {
 565         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 566         return FALSE;
 567     }
 568 #else
 569   if ( wxFile::Exists(m_strName) && remove(wxUnix2MacFilename( m_strName )) != 0 ) {
 570     wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 571     return FALSE;
 572   }
 573
 574   if ( rename(wxUnix2MacFilename( m_strTemp ), wxUnix2MacFilename( m_strName )) != 0 ) {
 575     wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 576     return FALSE;
 577   }
 578 #endif
 579
 580     return TRUE;
 581 }
 582
 583 void wxTempFile::Discard()
 584 {
 585     m_file.Close();
 586 #if !defined(__WXMAC__) || defined(__UNIX__)
 587     if ( wxRemove(m_strTemp) != 0 )
 588         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 589 #else
 590     if ( remove( wxUnix2MacFilename(m_strTemp.fn_str())) != 0 )
 591         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 592 #endif
 593 }
 594
 595 #endif
 596