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 #include "wx/defs.h"
  24
  25 #ifdef __BORLANDC__
  26     #pragma hdrstop
  27 #endif
  28
  29 // standard
  30 #if   defined(__WXMSW__) && !defined(__GNUWIN32__)
  31   #include  <io.h>
  32
  33 #ifndef __SALFORDC__
  34   #define   WIN32_LEAN_AND_MEAN
  35   #define   NOSERVICE
  36   #define   NOIME
  37   #define   NOATOM
  38   #define   NOGDI
  39   #define   NOGDICAPMASKS
  40   #define   NOMETAFILE
  41   #define   NOMINMAX
  42   #define   NOMSG
  43   #define   NOOPENFILE
  44   #define   NORASTEROPS
  45   #define   NOSCROLL
  46   #define   NOSOUND
  47   #define   NOSYSMETRICS
  48   #define   NOTEXTMETRIC
  49   #define   NOWH
  50   #define   NOCOMM
  51   #define   NOKANJI
  52   #define   NOCRYPT
  53   #define   NOMCX
  54 #endif
  55
  56   #include  <windows.h>     // for GetTempFileName
  57 #elif (defined(__UNIX__) || defined(__GNUWIN32__))
  58     #include  <unistd.h>
  59     #ifdef __GNUWIN32__
  60         #include <windows.h>
  61     #endif
  62 #elif (defined(__WXSTUBS__))
  63     // Have to ifdef this for different environments
  64     #include <io.h>
  65 #elif (defined(__WXMAC__))
  66     int access( const char *path, int mode ) { return 0 ; }
  67     char* mktemp( char * path ) { return path ;}
  68     #include  <unistd.h>
  69     #include  <unix.h>
  70     #define   W_OK        2
  71     #define   R_OK        4
  72 #else
  73     #error  "Please specify the header with file functions declarations."
  74 #endif  //Win/UNIX
  75
  76 #include  <stdio.h>       // SEEK_xxx constants
  77 #include  <fcntl.h>       // O_RDONLY &c
  78
  79 #ifndef __MWERKS__
  80     #include  <sys/types.h>   // needed for stat
  81     #include  <sys/stat.h>    // stat
  82 #endif
  83
  84 // Microsoft compiler loves underscores, feed them to it
  85 #ifdef  __VISUALC__
  86   // functions
  87   #define   open        _open
  88   #define   close       _close
  89   #define   read        _read
  90   #define   write       _write
  91   #define   lseek       _lseek
  92   #define   fsync       _commit
  93   #define   access      _access
  94   #define   eof         _eof
  95
  96   // types
  97   #define   stat        _stat
  98
  99   // constants
 100
 101   #define   O_RDONLY    _O_RDONLY
 102   #define   O_WRONLY    _O_WRONLY
 103   #define   O_RDWR      _O_RDWR
 104   #define   O_EXCL      _O_EXCL
 105   #define   O_CREAT     _O_CREAT
 106   #define   O_BINARY    _O_BINARY
 107
 108   #define   S_IFDIR     _S_IFDIR
 109   #define   S_IFREG     _S_IFREG
 110 #else
 111   #define   tell(fd)    lseek(fd, 0, SEEK_CUR)
 112 #endif  // VC++
 113
 114 #if defined(__BORLANDC__) || defined(_MSC_VER)
 115   #define   W_OK        2
 116   #define   R_OK        4
 117 #endif
 118
 119 // there is no distinction between text and binary files under Unix
 120 #ifdef    __UNIX__
 121   #define   O_BINARY    (0)
 122 #endif  //__UNIX__
 123
 124 #ifdef __SALFORDC__
 125     #include <unix.h>
 126 #endif
 127
 128 // wxWindows
 129 #include  <wx/string.h>
 130 #include  <wx/intl.h>
 131 #include  <wx/file.h>
 132 #include  <wx/log.h>
 133
 134 #ifndef MAX_PATH
 135     #define MAX_PATH 512
 136 #endif
 137
 138 #ifdef __WXMAC__
 139     char gwxMacFileName[ MAX_PATH ] ;
 140     char gwxMacFileName2[ MAX_PATH ] ;
 141     char gwxMacFileName3[ MAX_PATH ] ;
 142 #endif
 143
 144 // ============================================================================
 145 // implementation of wxFile
 146 // ============================================================================
 147
 148 // ----------------------------------------------------------------------------
 149 // static functions
 150 // ----------------------------------------------------------------------------
 151 bool wxFile::Exists(const char *name)
 152 {
 153 #ifdef __SALFORDC__
 154   struct _stat st;
 155 #else
 156   struct stat st;
 157 #endif
 158
 159   return !access(name, 0) && !stat((char*) name, &st) && (st.st_mode & S_IFREG);
 160 }
 161
 162 bool wxFile::Access(const char *name, OpenMode mode)
 163 {
 164   int how = 0;
 165
 166   switch ( mode ) {
 167     case read:
 168       how = R_OK;
 169       break;
 170
 171     case write:
 172       how = W_OK;
 173       break;
 174
 175     default:
 176       wxFAIL_MSG("bad wxFile::Access mode parameter.");
 177   }
 178
 179   return access(name, how) == 0;
 180 }
 181
 182 // ----------------------------------------------------------------------------
 183 // opening/closing
 184 // ----------------------------------------------------------------------------
 185
 186 // ctors
 187 wxFile::wxFile(const char *szFileName, OpenMode mode)
 188 {
 189   m_fd = fd_invalid;
 190   m_error = FALSE;
 191
 192   Open(szFileName, mode);
 193 }
 194
 195 // dtor
 196 wxFile::~wxFile()
 197 {
 198   Close();
 199 }
 200
 201 // create the file, fail if it already exists and bOverwrite
 202 bool wxFile::Create(const char *szFileName, bool bOverwrite, int accessMode)
 203 {
 204   // if bOverwrite we create a new file or truncate the existing one,
 205   // otherwise we only create the new file and fail if it already exists
 206 #ifdef __SALFORDC__
 207   int fd = open(szFileName, O_WRONLY | O_CREAT |
 208                 (bOverwrite ? O_TRUNC : O_EXCL));
 209 #else
 210   int fd = open(szFileName, O_WRONLY | O_CREAT |
 211                 (bOverwrite ? O_TRUNC : O_EXCL), accessMode);
 212 #endif
 213
 214   if ( fd == -1 ) {
 215     wxLogSysError(_("can't create file '%s'"), szFileName);
 216     return FALSE;
 217   }
 218   else {
 219     Attach(fd);
 220     return TRUE;
 221   }
 222 }
 223
 224 // open the file
 225 bool wxFile::Open(const char *szFileName, OpenMode mode, int accessMode)
 226 {
 227   int flags = O_BINARY;
 228
 229   switch ( mode ) {
 230     case read:
 231       flags |= O_RDONLY;
 232       break;
 233
 234     case write:
 235       flags |= O_WRONLY | O_CREAT | O_TRUNC;
 236       break;
 237
 238     case write_append:
 239       flags |= O_WRONLY | O_APPEND;
 240       break;
 241
 242     case read_write:
 243       flags |= O_RDWR;
 244       break;
 245   }
 246
 247 #ifdef __SALFORDC__
 248   int fd = open(szFileName, flags);
 249 #else
 250   int fd = open(szFileName, flags, accessMode);
 251 #endif
 252
 253   if ( fd == -1 ) {
 254     wxLogSysError(_("can't open file '%s'"), szFileName);
 255     return FALSE;
 256   }
 257   else {
 258     Attach(fd);
 259     return TRUE;
 260   }
 261 }
 262
 263 // close
 264 bool wxFile::Close()
 265 {
 266   if ( IsOpened() ) {
 267     if ( close(m_fd) == -1 ) {
 268       wxLogSysError(_("can't close file descriptor %d"), m_fd);
 269       m_fd = fd_invalid;
 270       return FALSE;
 271     }
 272     else
 273       m_fd = fd_invalid;
 274   }
 275
 276   return TRUE;
 277 }
 278
 279 // ----------------------------------------------------------------------------
 280 // read/write
 281 // ----------------------------------------------------------------------------
 282
 283 // read
 284 off_t wxFile::Read(void *pBuf, off_t nCount)
 285 {
 286   wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 287
 288 #ifdef __MWERKS__
 289   int iRc = ::read(m_fd, (char*) pBuf, nCount);
 290 #else
 291   int iRc = ::read(m_fd, pBuf, nCount);
 292 #endif
 293   if ( iRc == -1 ) {
 294     wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 295     return wxInvalidOffset;
 296   }
 297   else
 298     return (size_t)iRc;
 299 }
 300
 301 // write
 302 size_t wxFile::Write(const void *pBuf, size_t nCount)
 303 {
 304   wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 305
 306 #ifdef __MWERKS__
 307   int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 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 ( fsync(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 flag = -1;
 348   switch ( mode ) {
 349     case wxFromStart:
 350       flag = SEEK_SET;
 351       break;
 352
 353     case wxFromCurrent:
 354       flag = SEEK_CUR;
 355       break;
 356
 357     case wxFromEnd:
 358       flag = SEEK_END;
 359       break;
 360
 361     default:
 362       wxFAIL_MSG(_("unknown seek origin"));
 363   }
 364
 365   int iRc = lseek(m_fd, ofs, flag);
 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 = tell(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 = tell(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 \
 448 descriptor %d"), m_fd);
 449       break;
 450
 451     default:
 452       wxFAIL_MSG(_("invalid eof() return value."));
 453   }
 454
 455   return TRUE;
 456 }
 457
 458 // ============================================================================
 459 // implementation of wxTempFile
 460 // ============================================================================
 461
 462 // ----------------------------------------------------------------------------
 463 // construction
 464 // ----------------------------------------------------------------------------
 465 wxTempFile::wxTempFile(const wxString& strName)
 466 {
 467   Open(strName);
 468 }
 469
 470 bool wxTempFile::Open(const wxString& strName)
 471 {
 472   m_strName = strName;
 473
 474   // we want to create the file in the same directory as strName because
 475   // otherwise rename() in Commit() might not work (if the files are on
 476   // different partitions for example). Unfortunately, the only standard
 477   // (POSIX) temp file creation function tmpnam() can't do it.
 478   #if defined(__UNIX__) || defined(__WXSTUBS__)|| defined( __WXMAC__ )
 479     static const char *szMktempSuffix = "XXXXXX";
 480     m_strTemp << strName << szMktempSuffix;
 481     mktemp((char *)m_strTemp.c_str()); // will do because length doesn't change
 482   #else // Windows
 483     wxString strPath;
 484     wxSplitPath(strName, &strPath, NULL, NULL);
 485     if ( strPath.IsEmpty() )
 486       strPath = '.';  // GetTempFileName will fail if we give it empty string
 487 #ifdef __WIN32__
 488     if ( !GetTempFileName(strPath, "wx_",0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 489 #else
 490     // Not sure why MSVC++ 1.5 header defines first param as BYTE - bug?
 491     if ( !GetTempFileName((BYTE) (const char*) strPath, "wx_",0, m_strTemp.GetWriteBuf(MAX_PATH)) )
 492 #endif
 493       wxLogLastError("GetTempFileName");
 494     m_strTemp.UngetWriteBuf();
 495   #endif  // Windows/Unix
 496
 497   return m_file.Open(m_strTemp, wxFile::write);
 498 }
 499
 500 // ----------------------------------------------------------------------------
 501 // destruction
 502 // ----------------------------------------------------------------------------
 503
 504 wxTempFile::~wxTempFile()
 505 {
 506   if ( IsOpened() )
 507     Discard();
 508 }
 509
 510 bool wxTempFile::Commit()
 511 {
 512   m_file.Close();
 513
 514   if ( wxFile::Exists(m_strName) && remove(m_strName) != 0 ) {
 515     wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 516     return FALSE;
 517   }
 518
 519   if ( rename(m_strTemp, m_strName) != 0 ) {
 520     wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 521     return FALSE;
 522   }
 523
 524   return TRUE;
 525 }
 526
 527 void wxTempFile::Discard()
 528 {
 529   m_file.Close();
 530   if ( remove(m_strTemp) != 0 )
 531     wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 532 }