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