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__) && defined(__WATCOMC__)
  63     #include <io.h>
  64 #elif (defined(__WXPM__))
  65     #include <io.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 #if __MSL__ < 0x6000
  73     int access( const char *path, int mode ) { return 0 ; }
  74 #else
  75     int _access( const char *path, int mode ) { return 0 ; }
  76 #endif
  77     char* mktemp( char * path ) { return path ;}
  78     #include <stat.h>
  79     #define   W_OK        2
  80     #define   R_OK        4
  81     #include  <unistd.h>
  82 #else
  83     #error  "Please specify the header with file functions declarations."
  84 #endif  //Win/UNIX
  85
  86 #include  <stdio.h>       // SEEK_xxx constants
  87 #include  <fcntl.h>       // O_RDONLY &c
  88
  89 #ifndef __MWERKS__
  90     #include  <sys/types.h>   // needed for stat
  91     #include  <sys/stat.h>    // stat
  92 #elif ( defined(__MWERKS__) && defined(__WXMSW__) )
  93     #include  <sys/types.h>   // needed for stat
  94     #include  <sys/stat.h>    // stat
  95 #endif
  96
  97 #if defined(__BORLANDC__) || defined(_MSC_VER)
  98     #define   W_OK        2
  99     #define   R_OK        4
 100 #endif
 101
 102 // there is no distinction between text and binary files under Unix, so define
 103 // O_BINARY as 0 if the system headers don't do it already
 104 #if defined(__UNIX__) && !defined(O_BINARY)
 105     #define   O_BINARY    (0)
 106 #endif  //__UNIX__
 107
 108 #ifdef __SALFORDC__
 109     #include <unix.h>
 110 #endif
 111
 112 #ifndef MAX_PATH
 113     #define MAX_PATH 512
 114 #endif
 115
 116 // some broken compilers don't have 3rd argument in open() and creat()
 117 #ifdef __SALFORDC__
 118     #define ACCESS(access)
 119     #define stat    _stat
 120 #else // normal compiler
 121     #define ACCESS(access)  , (access)
 122 #endif // Salford C
 123
 124 // wxWindows
 125 #ifndef WX_PRECOMP
 126     #include  "wx/string.h"
 127     #include  "wx/intl.h"
 128     #include  "wx/log.h"
 129 #endif // !WX_PRECOMP
 130
 131 #include  "wx/filename.h"
 132 #include  "wx/file.h"
 133
 134 // ============================================================================
 135 // implementation of wxFile
 136 // ============================================================================
 137
 138 // ----------------------------------------------------------------------------
 139 // static functions
 140 // ----------------------------------------------------------------------------
 141 bool wxFile::Exists(const wxChar *name)
 142 {
 143     wxStructStat st;
 144 #if wxUSE_UNICODE && wxMBFILES
 145     wxCharBuffer fname = wxConvFile.cWC2MB(name);
 146
 147     return !wxAccess(fname, 0) &&
 148            !wxStat(wxMBSTRINGCAST fname, &st) &&
 149            (st.st_mode & S_IFREG);
 150
 151 #else
 152     return !wxAccess(name, 0) &&
 153            !wxStat(name, &st) &&
 154            (st.st_mode & S_IFREG);
 155 #endif
 156 }
 157
 158 bool wxFile::Access(const wxChar *name, OpenMode mode)
 159 {
 160     int how = 0;
 161
 162     switch ( mode ) {
 163         case read:
 164             how = R_OK;
 165             break;
 166
 167         case write:
 168             how = W_OK;
 169             break;
 170
 171         default:
 172             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 173     }
 174
 175     return wxAccess(wxFNCONV(name), how) == 0;
 176 }
 177
 178 // ----------------------------------------------------------------------------
 179 // opening/closing
 180 // ----------------------------------------------------------------------------
 181
 182 // ctors
 183 wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
 184 {
 185     m_fd = fd_invalid;
 186     m_error = FALSE;
 187
 188     Open(szFileName, mode);
 189 }
 190
 191 // create the file, fail if it already exists and bOverwrite
 192 bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
 193 {
 194     // if bOverwrite we create a new file or truncate the existing one,
 195     // otherwise we only create the new file and fail if it already exists
 196 #if defined(__WXMAC__) && !defined(__UNIX__)
 197   // Dominic Mazzoni [dmazzoni+@cs.cmu.edu] reports that open is still broken on the mac, so we replace
 198   // int fd = open(wxUnix2MacFilename( szFileName ), O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 199   int fd = creat( szFileName , accessMode);
 200 #else
 201     int fd = wxOpen(wxFNCONV(szFileName),
 202                     O_BINARY | O_WRONLY | O_CREAT |
 203                     (bOverwrite ? O_TRUNC : O_EXCL)
 204                     ACCESS(accessMode));
 205 #endif
 206     if ( fd == -1 ) {
 207         wxLogSysError(_("can't create file '%s'"), szFileName);
 208         return FALSE;
 209     }
 210     else {
 211         Attach(fd);
 212         return TRUE;
 213     }
 214 }
 215
 216 // open the file
 217 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 218 {
 219     int flags = O_BINARY;
 220
 221     switch ( mode ) {
 222         case read:
 223             flags |= O_RDONLY;
 224             break;
 225
 226         case write_append:
 227             if ( wxFile::Exists(szFileName) )
 228             {
 229                 flags |= O_WRONLY | O_APPEND;
 230                 break;
 231             }
 232             //else: fall through as write_append is the same as write if the
 233             //      file doesn't exist
 234
 235         case write:
 236             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 237             break;
 238
 239         case write_excl:
 240             flags |= O_WRONLY | O_CREAT | O_EXCL;
 241             break;
 242
 243         case read_write:
 244             flags |= O_RDWR;
 245             break;
 246     }
 247
 248     int fd = wxOpen(wxFNCONV(szFileName), flags ACCESS(accessMode));
 249     if ( fd == -1 ) {
 250         wxLogSysError(_("can't open file '%s'"), szFileName);
 251         return FALSE;
 252     }
 253     else {
 254         Attach(fd);
 255         return TRUE;
 256     }
 257 }
 258
 259 // close
 260 bool wxFile::Close()
 261 {
 262     if ( IsOpened() ) {
 263         if ( close(m_fd) == -1 ) {
 264             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 265             m_fd = fd_invalid;
 266             return FALSE;
 267         }
 268         else
 269             m_fd = fd_invalid;
 270     }
 271
 272     return TRUE;
 273 }
 274
 275 // ----------------------------------------------------------------------------
 276 // read/write
 277 // ----------------------------------------------------------------------------
 278
 279 // read
 280 off_t wxFile::Read(void *pBuf, off_t nCount)
 281 {
 282     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 283
 284 #ifdef __MWERKS__
 285     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 286 #else
 287     int iRc = ::read(m_fd, pBuf, nCount);
 288 #endif
 289     if ( iRc == -1 ) {
 290         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 291         return wxInvalidOffset;
 292     }
 293     else
 294         return (size_t)iRc;
 295 }
 296
 297 // write
 298 size_t wxFile::Write(const void *pBuf, size_t nCount)
 299 {
 300     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 301
 302 #ifdef __MWERKS__
 303 #if __MSL__ >= 0x6000
 304     int iRc = ::write(m_fd, (void*) pBuf, nCount);
 305 #else
 306     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 307 #endif
 308 #else
 309     int iRc = ::write(m_fd, pBuf, nCount);
 310 #endif
 311     if ( iRc == -1 ) {
 312         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 313         m_error = TRUE;
 314         return 0;
 315     }
 316     else
 317         return iRc;
 318 }
 319
 320 // flush
 321 bool wxFile::Flush()
 322 {
 323     if ( IsOpened() ) {
 324 #if defined(__VISUALC__) || wxHAVE_FSYNC
 325         if ( wxFsync(m_fd) == -1 )
 326         {
 327             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 328             return FALSE;
 329         }
 330 #else // no fsync
 331         // just do nothing
 332 #endif // fsync
 333     }
 334
 335     return TRUE;
 336 }
 337
 338 // ----------------------------------------------------------------------------
 339 // seek
 340 // ----------------------------------------------------------------------------
 341
 342 // seek
 343 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 344 {
 345     wxASSERT( IsOpened() );
 346
 347     int origin;
 348     switch ( mode ) {
 349         default:
 350             wxFAIL_MSG(_("unknown seek origin"));
 351
 352         case wxFromStart:
 353             origin = SEEK_SET;
 354             break;
 355
 356         case wxFromCurrent:
 357             origin = SEEK_CUR;
 358             break;
 359
 360         case wxFromEnd:
 361             origin = SEEK_END;
 362             break;
 363     }
 364
 365     int iRc = lseek(m_fd, ofs, origin);
 366     if ( iRc == -1 ) {
 367         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 368         return wxInvalidOffset;
 369     }
 370     else
 371         return (off_t)iRc;
 372 }
 373
 374 // get current off_t
 375 off_t wxFile::Tell() const
 376 {
 377     wxASSERT( IsOpened() );
 378
 379     int iRc = wxTell(m_fd);
 380     if ( iRc == -1 ) {
 381         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 382         return wxInvalidOffset;
 383     }
 384     else
 385         return (off_t)iRc;
 386 }
 387
 388 // get current file length
 389 off_t wxFile::Length() const
 390 {
 391     wxASSERT( IsOpened() );
 392
 393 #ifdef __VISUALC__
 394     int iRc = _filelength(m_fd);
 395 #else // !VC++
 396     int iRc = wxTell(m_fd);
 397     if ( iRc != -1 ) {
 398         // @ have to use const_cast :-(
 399         int iLen = ((wxFile *)this)->SeekEnd();
 400         if ( iLen != -1 ) {
 401             // restore old position
 402             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 403                 // error
 404                 iLen = -1;
 405             }
 406         }
 407
 408         iRc = iLen;
 409     }
 410 #endif  // VC++
 411
 412     if ( iRc == -1 ) {
 413         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 414         return wxInvalidOffset;
 415     }
 416     else
 417         return (off_t)iRc;
 418 }
 419
 420 // is end of file reached?
 421 bool wxFile::Eof() const
 422 {
 423     wxASSERT( IsOpened() );
 424
 425     int iRc;
 426
 427 #if defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 428     // @@ this doesn't work, of course, on unseekable file descriptors
 429     off_t ofsCur = Tell(),
 430     ofsMax = Length();
 431     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 432         iRc = -1;
 433     else
 434         iRc = ofsCur == ofsMax;
 435 #else  // Windows and "native" compiler
 436     iRc = eof(m_fd);
 437 #endif // Windows/Unix
 438
 439     switch ( iRc ) {
 440         case 1:
 441             break;
 442
 443         case 0:
 444             return FALSE;
 445
 446         case -1:
 447             wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
 448                 break;
 449
 450         default:
 451             wxFAIL_MSG(_("invalid eof() return value."));
 452     }
 453
 454     return TRUE;
 455 }
 456
 457 // ============================================================================
 458 // implementation of wxTempFile
 459 // ============================================================================
 460
 461 // ----------------------------------------------------------------------------
 462 // construction
 463 // ----------------------------------------------------------------------------
 464 wxTempFile::wxTempFile(const wxString& strName)
 465 {
 466     Open(strName);
 467 }
 468
 469 bool wxTempFile::Open(const wxString& strName)
 470 {
 471     m_strName = strName;
 472
 473     m_strTemp = wxFileName::CreateTempFileName(strName);
 474
 475     if ( m_strTemp.empty() )
 476     {
 477         // CreateTempFileName() failed
 478         return FALSE;
 479     }
 480
 481     // actually open the file now (it must already exist)
 482     if ( !m_file.Open(m_strTemp, wxFile::write) )
 483     {
 484         // opening existing file failed?
 485         return FALSE;
 486     }
 487
 488 #ifdef __UNIX__
 489     // the temp file should have the same permissions as the original one
 490     mode_t mode;
 491
 492     wxStructStat st;
 493     if ( stat(strName.fn_str(), &st) == 0 )
 494     {
 495         mode = st.st_mode;
 496     }
 497     else
 498     {
 499         // file probably didn't exist, just give it the default mode _using_
 500         // user's umask (new files creation should respect umask)
 501         mode_t mask = umask(0777);
 502         mode = 0666 & ~mask;
 503         umask(mask);
 504     }
 505
 506     if ( chmod(m_strTemp.mb_str(), mode) == -1 )
 507     {
 508         wxLogSysError(_("Failed to set temporary file permissions"));
 509     }
 510 #endif // Unix
 511
 512     return TRUE;
 513 }
 514
 515 // ----------------------------------------------------------------------------
 516 // destruction
 517 // ----------------------------------------------------------------------------
 518
 519 wxTempFile::~wxTempFile()
 520 {
 521     if ( IsOpened() )
 522         Discard();
 523 }
 524
 525 bool wxTempFile::Commit()
 526 {
 527     m_file.Close();
 528
 529     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 530         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 531         return FALSE;
 532     }
 533
 534     if ( wxRename(m_strTemp, m_strName) != 0 ) {
 535         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 536         return FALSE;
 537     }
 538
 539     return TRUE;
 540 }
 541
 542 void wxTempFile::Discard()
 543 {
 544     m_file.Close();
 545     if ( wxRemove(m_strTemp) != 0 )
 546         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 547 }
 548
 549 #endif // wxUSE_FILE
 550