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
 126 #ifdef    __UNIX__
 127     #define   O_BINARY    (0)
 128 #endif  //__UNIX__
 129
 130 #ifdef __SALFORDC__
 131     #include <unix.h>
 132 #endif
 133
 134 // wxWindows
 135 #include  "wx/string.h"
 136 #include  "wx/intl.h"
 137 #include  "wx/file.h"
 138 #include  "wx/log.h"
 139
 140 #ifndef MAX_PATH
 141     #define MAX_PATH 512
 142 #endif
 143
 144 // some broken compilers don't have 3rd argument in open() and creat()
 145 #ifdef __SALFORDC__
 146     #define ACCESS(access)
 147     #define stat    _stat
 148 #else // normal compiler
 149     #define ACCESS(access)  , (access)
 150 #endif // Salford C
 151
 152 // ============================================================================
 153 // implementation of wxFile
 154 // ============================================================================
 155
 156 // ----------------------------------------------------------------------------
 157 // static functions
 158 // ----------------------------------------------------------------------------
 159 bool wxFile::Exists(const wxChar *name)
 160 {
 161     struct stat st;
 162 #if wxUSE_UNICODE && wxMBFILES
 163     wxCharBuffer fname = wxConvFile.cWC2MB(name);
 164
 165 #ifdef __WXMAC__
 166   return !access(wxUnix2MacFilename( name ) , 0) && !stat(wxUnix2MacFilename( name ), &st) && (st.st_mode & S_IFREG);
 167 #else
 168     return !access(fname, 0) &&
 169            !stat(wxMBSTRINGCAST fname, &st) &&
 170            (st.st_mode & S_IFREG);
 171 #endif
 172 #else
 173 #ifdef __WXMAC__
 174   return !access(wxUnix2MacFilename( name ) , 0) && !stat(wxUnix2MacFilename( name ), &st) && (st.st_mode & S_IFREG);
 175 #else
 176     return !access(name, 0) &&
 177            !stat((wxChar*) name, &st) &&
 178            (st.st_mode & S_IFREG);
 179 #endif
 180 #endif
 181 }
 182
 183 bool wxFile::Access(const wxChar *name, OpenMode mode)
 184 {
 185     int how = 0;
 186
 187     switch ( mode ) {
 188         case read:
 189             how = R_OK;
 190             break;
 191
 192         case write:
 193             how = W_OK;
 194             break;
 195
 196         default:
 197             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 198     }
 199
 200     return access(wxFNCONV(name), how) == 0;
 201 }
 202
 203 // ----------------------------------------------------------------------------
 204 // opening/closing
 205 // ----------------------------------------------------------------------------
 206
 207 // ctors
 208 wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
 209 {
 210     m_fd = fd_invalid;
 211     m_error = FALSE;
 212
 213     Open(szFileName, mode);
 214 }
 215
 216 // create the file, fail if it already exists and bOverwrite
 217 bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
 218 {
 219     // if bOverwrite we create a new file or truncate the existing one,
 220     // otherwise we only create the new file and fail if it already exists
 221 #ifdef __WXMAC__
 222   int fd = open(wxUnix2MacFilename( szFileName ), O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 223 #else
 224     int fd = open(wxFNCONV(szFileName),
 225                   O_WRONLY | O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL)
 226                   ACCESS(accessMode));
 227 #endif
 228     if ( fd == -1 ) {
 229         wxLogSysError(_("can't create file '%s'"), szFileName);
 230         return FALSE;
 231     }
 232     else {
 233         Attach(fd);
 234         return TRUE;
 235     }
 236 }
 237
 238 // open the file
 239 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 240 {
 241     int flags = O_BINARY;
 242
 243     switch ( mode ) {
 244         case read:
 245             flags |= O_RDONLY;
 246             break;
 247
 248         case write:
 249             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 250             break;
 251
 252         case write_append:
 253             flags |= O_WRONLY | O_APPEND;
 254             break;
 255
 256         case read_write:
 257             flags |= O_RDWR;
 258             break;
 259     }
 260
 261 #ifdef __WXMAC__
 262   int fd = open(wxUnix2MacFilename( szFileName ), flags, access);
 263 #else
 264     int fd = open(wxFNCONV(szFileName), flags ACCESS(accessMode));
 265 #endif
 266     if ( fd == -1 ) {
 267         wxLogSysError(_("can't open file '%s'"), szFileName);
 268         return FALSE;
 269     }
 270     else {
 271         Attach(fd);
 272         return TRUE;
 273     }
 274 }
 275
 276 // close
 277 bool wxFile::Close()
 278 {
 279     if ( IsOpened() ) {
 280         if ( close(m_fd) == -1 ) {
 281             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 282             m_fd = fd_invalid;
 283             return FALSE;
 284         }
 285         else
 286             m_fd = fd_invalid;
 287     }
 288
 289     return TRUE;
 290 }
 291
 292 // ----------------------------------------------------------------------------
 293 // read/write
 294 // ----------------------------------------------------------------------------
 295
 296 // read
 297 off_t wxFile::Read(void *pBuf, off_t nCount)
 298 {
 299     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 300
 301 #ifdef __MWERKS__
 302     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 303 #else
 304     int iRc = ::read(m_fd, pBuf, nCount);
 305 #endif
 306     if ( iRc == -1 ) {
 307         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 308         return wxInvalidOffset;
 309     }
 310     else
 311         return (size_t)iRc;
 312 }
 313
 314 // write
 315 size_t wxFile::Write(const void *pBuf, size_t nCount)
 316 {
 317     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 318
 319 #ifdef __MWERKS__
 320     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 321 #else
 322     int iRc = ::write(m_fd, pBuf, nCount);
 323 #endif
 324     if ( iRc == -1 ) {
 325         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 326         m_error = TRUE;
 327         return 0;
 328     }
 329     else
 330         return iRc;
 331 }
 332
 333 // flush
 334 bool wxFile::Flush()
 335 {
 336     if ( IsOpened() ) {
 337 #if defined(__VISUALC__) || wxHAVE_FSYNC
 338         if ( fsync(m_fd) == -1 )
 339         {
 340             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 341             return FALSE;
 342         }
 343 #else // no fsync
 344         // just do nothing
 345 #endif // fsync
 346     }
 347
 348     return TRUE;
 349 }
 350
 351 // ----------------------------------------------------------------------------
 352 // seek
 353 // ----------------------------------------------------------------------------
 354
 355 // seek
 356 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 357 {
 358     wxASSERT( IsOpened() );
 359
 360     int origin;
 361     switch ( mode ) {
 362         default:
 363             wxFAIL_MSG(_("unknown seek origin"));
 364
 365         case wxFromStart:
 366             origin = SEEK_SET;
 367             break;
 368
 369         case wxFromCurrent:
 370             origin = SEEK_CUR;
 371             break;
 372
 373         case wxFromEnd:
 374             origin = SEEK_END;
 375             break;
 376     }
 377
 378     int iRc = lseek(m_fd, ofs, origin);
 379     if ( iRc == -1 ) {
 380         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 381         return wxInvalidOffset;
 382     }
 383     else
 384         return (off_t)iRc;
 385 }
 386
 387 // get current off_t
 388 off_t wxFile::Tell() const
 389 {
 390     wxASSERT( IsOpened() );
 391
 392     int iRc = tell(m_fd);
 393     if ( iRc == -1 ) {
 394         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 395         return wxInvalidOffset;
 396     }
 397     else
 398         return (off_t)iRc;
 399 }
 400
 401 // get current file length
 402 off_t wxFile::Length() const
 403 {
 404     wxASSERT( IsOpened() );
 405
 406 #ifdef __VISUALC__
 407     int iRc = _filelength(m_fd);
 408 #else // !VC++
 409     int iRc = tell(m_fd);
 410     if ( iRc != -1 ) {
 411         // @ have to use const_cast :-(
 412         int iLen = ((wxFile *)this)->SeekEnd();
 413         if ( iLen != -1 ) {
 414             // restore old position
 415             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 416                 // error
 417                 iLen = -1;
 418             }
 419         }
 420
 421         iRc = iLen;
 422     }
 423 #endif  // VC++
 424
 425     if ( iRc == -1 ) {
 426         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 427         return wxInvalidOffset;
 428     }
 429     else
 430         return (off_t)iRc;
 431 }
 432
 433 // is end of file reached?
 434 bool wxFile::Eof() const
 435 {
 436     wxASSERT( IsOpened() );
 437
 438     int iRc;
 439
 440 #if defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 441     // @@ this doesn't work, of course, on unseekable file descriptors
 442     off_t ofsCur = Tell(),
 443     ofsMax = Length();
 444     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 445         iRc = -1;
 446     else
 447         iRc = ofsCur == ofsMax;
 448 #else  // Windows and "native" compiler
 449     iRc = eof(m_fd);
 450 #endif // Windows/Unix
 451
 452     switch ( iRc ) {
 453         case 1:
 454             break;
 455
 456         case 0:
 457             return FALSE;
 458
 459         case -1:
 460             wxLogSysError(_("can't determine if the end of file is reached on \
 461                 descriptor %d"), m_fd);
 462                 break;
 463
 464         default:
 465             wxFAIL_MSG(_("invalid eof() return value."));
 466     }
 467
 468     return TRUE;
 469 }
 470
 471 // ============================================================================
 472 // implementation of wxTempFile
 473 // ============================================================================
 474
 475 // ----------------------------------------------------------------------------
 476 // construction
 477 // ----------------------------------------------------------------------------
 478 wxTempFile::wxTempFile(const wxString& strName)
 479 {
 480     Open(strName);
 481 }
 482
 483 bool wxTempFile::Open(const wxString& strName)
 484 {
 485     m_strName = strName;
 486
 487     // we want to create the file in the same directory as strName because
 488     // otherwise rename() in Commit() might not work (if the files are on
 489     // different partitions for example). Unfortunately, the only standard
 490     // (POSIX) temp file creation function tmpnam() can't do it.
 491 #if defined(__UNIX__) || defined(__WXSTUBS__)|| defined( __WXMAC__ )
 492     static const wxChar *szMktempSuffix = wxT("XXXXXX");
 493     m_strTemp << strName << szMktempSuffix;
 494     // can use the cast because length doesn't change
 495     mktemp(wxMBSTRINGCAST m_strTemp.mb_str());
 496 #elif  defined(__WXPM__)
 497     // for now just create a file
 498     // future enhancements can be to set some extended attributes for file systems
 499     // OS/2 supports that have them (HPFS, FAT32) and security (HPFS386)
 500     static const wxChar *szMktempSuffix = wxT("XXX");
 501     m_strTemp << strName << szMktempSuffix;
 502     mkdir(m_strTemp.GetWriteBuf(MAX_PATH));
 503 #else // Windows
 504     wxString strPath;
 505     wxSplitPath(strName, &strPath, NULL, NULL);
 506     if ( strPath.IsEmpty() )
 507         strPath = wxT('.');  // GetTempFileName will fail if we give it empty string
 508 #ifdef __WIN32__
 509     if ( !GetTempFileName(strPath, wxT("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 510 #else
 511         // Not sure why MSVC++ 1.5 header defines first param as BYTE - bug?
 512         if ( !GetTempFileName((BYTE) (DWORD)(const wxChar*) strPath, wxT("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 513 #endif
 514             wxLogLastError(wxT("GetTempFileName"));
 515     m_strTemp.UngetWriteBuf();
 516 #endif  // Windows/Unix
 517
 518     int access = wxS_DEFAULT;
 519 #ifdef __UNIX__
 520     // create the file with the same mode as the original one under Unix
 521     mode_t umaskOld = 0; // just to suppress compiler warning
 522     bool changedUmask;
 523
 524     struct stat st;
 525     if ( stat(strName.fn_str(), &st) == 0 )
 526     {
 527         // this assumes that only lower bits of st_mode contain the access
 528         // rights, but it's true for at least all Unices which have S_IXXXX()
 529         // macros, so should not be less portable than using (not POSIX)
 530         // S_IFREG &c
 531         access = st.st_mode & 0777;
 532
 533         // we want to create the file with exactly the same access rights as
 534         // the original one, so disable the user's umask for the moment
 535         umaskOld = umask(0);
 536         changedUmask = TRUE;
 537     }
 538     else
 539     {
 540         // file probably didn't exist, just create with default mode _using_
 541         // user's umask (new files creation should respet umask)
 542         changedUmask = FALSE;
 543     }
 544 #endif // Unix
 545
 546     bool ok = m_file.Open(m_strTemp, wxFile::write, access);
 547
 548 #ifdef __UNIX__
 549     if ( changedUmask )
 550     {
 551         // restore umask now that the file is created
 552         (void)umask(umaskOld);
 553     }
 554 #endif // Unix
 555
 556     return ok;
 557 }
 558
 559 // ----------------------------------------------------------------------------
 560 // destruction
 561 // ----------------------------------------------------------------------------
 562
 563 wxTempFile::~wxTempFile()
 564 {
 565     if ( IsOpened() )
 566         Discard();
 567 }
 568
 569 bool wxTempFile::Commit()
 570 {
 571     m_file.Close();
 572
 573 #ifndef __WXMAC__
 574     if ( wxFile::Exists(m_strName) && remove(m_strName.fn_str()) != 0 ) {
 575         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 576         return FALSE;
 577     }
 578
 579     if ( rename(m_strTemp.fn_str(), m_strName.fn_str()) != 0 ) {
 580         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 581         return FALSE;
 582     }
 583 #else
 584   if ( wxFile::Exists(m_strName) && remove(wxUnix2MacFilename( m_strName )) != 0 ) {
 585     wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 586     return FALSE;
 587   }
 588
 589   if ( rename(wxUnix2MacFilename( m_strTemp ), wxUnix2MacFilename( m_strName )) != 0 ) {
 590     wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 591     return FALSE;
 592   }
 593 #endif
 594
 595     return TRUE;
 596 }
 597
 598 void wxTempFile::Discard()
 599 {
 600     m_file.Close();
 601 #ifndef __WXMAC__
 602     if ( remove(m_strTemp.fn_str()) != 0 )
 603         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 604 #else
 605     if ( remove( wxUnix2MacFilename(m_strTemp.fn_str())) != 0 )
 606         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 607 #endif
 608 }
 609
 610 #endif
 611