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     char* mktemp(char *path) { return _mktemp(path); }
  65 #elif (defined(__WXPM__))
  66     #include <io.h>
  67     #define   W_OK        2
  68     #define   R_OK        4
  69 #elif (defined(__WXSTUBS__))
  70     // Have to ifdef this for different environments
  71     #include <io.h>
  72 #elif (defined(__WXMAC__))
  73 #if __MSL__ < 0x6000
  74     int access( const char *path, int mode ) { return 0 ; }
  75 #else
  76     int _access( const char *path, int mode ) { return 0 ; }
  77 #endif
  78     char* mktemp( char * path ) { return path ;}
  79     #include <stat.h>
  80     #define   W_OK        2
  81     #define   R_OK        4
  82     #include  <unistd.h>
  83 #else
  84     #error  "Please specify the header with file functions declarations."
  85 #endif  //Win/UNIX
  86
  87 #include  <stdio.h>       // SEEK_xxx constants
  88 #include  <fcntl.h>       // O_RDONLY &c
  89
  90 #ifndef __MWERKS__
  91     #include  <sys/types.h>   // needed for stat
  92     #include  <sys/stat.h>    // stat
  93 #elif ( defined(__MWERKS__) && defined(__WXMSW__) )
  94     #include  <sys/types.h>   // needed for stat
  95     #include  <sys/stat.h>    // stat
  96 #endif
  97
  98 #if defined(__BORLANDC__) || defined(_MSC_VER)
  99     #define   W_OK        2
 100     #define   R_OK        4
 101 #endif
 102
 103 // there is no distinction between text and binary files under Unix, so define
 104 // O_BINARY as 0 if the system headers don't do it already
 105 #if defined(__UNIX__) && !defined(O_BINARY)
 106     #define   O_BINARY    (0)
 107 #endif  //__UNIX__
 108
 109 #ifdef __SALFORDC__
 110     #include <unix.h>
 111 #endif
 112
 113 #ifndef MAX_PATH
 114     #define MAX_PATH 512
 115 #endif
 116
 117 // some broken compilers don't have 3rd argument in open() and creat()
 118 #ifdef __SALFORDC__
 119     #define ACCESS(access)
 120     #define stat    _stat
 121 #else // normal compiler
 122     #define ACCESS(access)  , (access)
 123 #endif // Salford C
 124
 125 // wxWindows
 126 #ifndef WX_PRECOMP
 127     #include  "wx/string.h"
 128     #include  "wx/intl.h"
 129     #include  "wx/log.h"
 130 #endif // !WX_PRECOMP
 131
 132 #include  "wx/filename.h"
 133 #include  "wx/file.h"
 134
 135 // ============================================================================
 136 // implementation of wxFile
 137 // ============================================================================
 138
 139 // ----------------------------------------------------------------------------
 140 // static functions
 141 // ----------------------------------------------------------------------------
 142 bool wxFile::Exists(const wxChar *name)
 143 {
 144     wxStructStat st;
 145 #if wxUSE_UNICODE && wxMBFILES
 146     wxCharBuffer fname = wxConvFile.cWC2MB(name);
 147
 148     return !wxAccess(fname, 0) &&
 149            !wxStat(wxMBSTRINGCAST fname, &st) &&
 150            (st.st_mode & S_IFREG);
 151
 152 #else
 153     return !wxAccess(name, 0) &&
 154            !wxStat(name, &st) &&
 155            (st.st_mode & S_IFREG);
 156 #endif
 157 }
 158
 159 bool wxFile::Access(const wxChar *name, OpenMode mode)
 160 {
 161     int how = 0;
 162
 163     switch ( mode ) {
 164         case read:
 165             how = R_OK;
 166             break;
 167
 168         case write:
 169             how = W_OK;
 170             break;
 171
 172         default:
 173             wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
 174     }
 175
 176     return wxAccess(wxFNCONV(name), how) == 0;
 177 }
 178
 179 // ----------------------------------------------------------------------------
 180 // opening/closing
 181 // ----------------------------------------------------------------------------
 182
 183 // ctors
 184 wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
 185 {
 186     m_fd = fd_invalid;
 187     m_error = FALSE;
 188
 189     Open(szFileName, mode);
 190 }
 191
 192 // create the file, fail if it already exists and bOverwrite
 193 bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
 194 {
 195     // if bOverwrite we create a new file or truncate the existing one,
 196     // otherwise we only create the new file and fail if it already exists
 197 #if defined(__WXMAC__) && !defined(__UNIX__)
 198   // Dominic Mazzoni [dmazzoni+@cs.cmu.edu] reports that open is still broken on the mac, so we replace
 199   // int fd = open(wxUnix2MacFilename( szFileName ), O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL), access);
 200   int fd = creat( szFileName , accessMode);
 201 #else
 202     int fd = wxOpen(wxFNCONV(szFileName),
 203                     O_BINARY | O_WRONLY | O_CREAT |
 204                     (bOverwrite ? O_TRUNC : O_EXCL)
 205                     ACCESS(accessMode));
 206 #endif
 207     if ( fd == -1 ) {
 208         wxLogSysError(_("can't create file '%s'"), szFileName);
 209         return FALSE;
 210     }
 211     else {
 212         Attach(fd);
 213         return TRUE;
 214     }
 215 }
 216
 217 // open the file
 218 bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
 219 {
 220     int flags = O_BINARY;
 221
 222     switch ( mode ) {
 223         case read:
 224             flags |= O_RDONLY;
 225             break;
 226
 227         case write_append:
 228             if ( wxFile::Exists(szFileName) )
 229             {
 230                 flags |= O_WRONLY | O_APPEND;
 231                 break;
 232             }
 233             //else: fall through as write_append is the same as write if the
 234             //      file doesn't exist
 235
 236         case write:
 237             flags |= O_WRONLY | O_CREAT | O_TRUNC;
 238             break;
 239
 240         case write_excl:
 241             flags |= O_WRONLY | O_CREAT | O_EXCL;
 242             break;
 243
 244         case read_write:
 245             flags |= O_RDWR;
 246             break;
 247     }
 248
 249     int fd = wxOpen(wxFNCONV(szFileName), flags ACCESS(accessMode));
 250     if ( fd == -1 ) {
 251         wxLogSysError(_("can't open file '%s'"), szFileName);
 252         return FALSE;
 253     }
 254     else {
 255         Attach(fd);
 256         return TRUE;
 257     }
 258 }
 259
 260 // close
 261 bool wxFile::Close()
 262 {
 263     if ( IsOpened() ) {
 264         if ( close(m_fd) == -1 ) {
 265             wxLogSysError(_("can't close file descriptor %d"), m_fd);
 266             m_fd = fd_invalid;
 267             return FALSE;
 268         }
 269         else
 270             m_fd = fd_invalid;
 271     }
 272
 273     return TRUE;
 274 }
 275
 276 // ----------------------------------------------------------------------------
 277 // read/write
 278 // ----------------------------------------------------------------------------
 279
 280 // read
 281 off_t wxFile::Read(void *pBuf, off_t nCount)
 282 {
 283     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 284
 285 #ifdef __MWERKS__
 286     int iRc = ::read(m_fd, (char*) pBuf, nCount);
 287 #else
 288     int iRc = ::read(m_fd, pBuf, nCount);
 289 #endif
 290     if ( iRc == -1 ) {
 291         wxLogSysError(_("can't read from file descriptor %d"), m_fd);
 292         return wxInvalidOffset;
 293     }
 294     else
 295         return (size_t)iRc;
 296 }
 297
 298 // write
 299 size_t wxFile::Write(const void *pBuf, size_t nCount)
 300 {
 301     wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
 302
 303 #ifdef __MWERKS__
 304 #if __MSL__ >= 0x6000
 305     int iRc = ::write(m_fd, (void*) pBuf, nCount);
 306 #else
 307     int iRc = ::write(m_fd, (const char*) pBuf, nCount);
 308 #endif
 309 #else
 310     int iRc = ::write(m_fd, pBuf, nCount);
 311 #endif
 312     if ( iRc == -1 ) {
 313         wxLogSysError(_("can't write to file descriptor %d"), m_fd);
 314         m_error = TRUE;
 315         return 0;
 316     }
 317     else
 318         return iRc;
 319 }
 320
 321 // flush
 322 bool wxFile::Flush()
 323 {
 324     if ( IsOpened() ) {
 325 #if defined(__VISUALC__) || wxHAVE_FSYNC
 326         if ( wxFsync(m_fd) == -1 )
 327         {
 328             wxLogSysError(_("can't flush file descriptor %d"), m_fd);
 329             return FALSE;
 330         }
 331 #else // no fsync
 332         // just do nothing
 333 #endif // fsync
 334     }
 335
 336     return TRUE;
 337 }
 338
 339 // ----------------------------------------------------------------------------
 340 // seek
 341 // ----------------------------------------------------------------------------
 342
 343 // seek
 344 off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
 345 {
 346     wxASSERT( IsOpened() );
 347
 348     int origin;
 349     switch ( mode ) {
 350         default:
 351             wxFAIL_MSG(_("unknown seek origin"));
 352
 353         case wxFromStart:
 354             origin = SEEK_SET;
 355             break;
 356
 357         case wxFromCurrent:
 358             origin = SEEK_CUR;
 359             break;
 360
 361         case wxFromEnd:
 362             origin = SEEK_END;
 363             break;
 364     }
 365
 366     int iRc = lseek(m_fd, ofs, origin);
 367     if ( iRc == -1 ) {
 368         wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
 369         return wxInvalidOffset;
 370     }
 371     else
 372         return (off_t)iRc;
 373 }
 374
 375 // get current off_t
 376 off_t wxFile::Tell() const
 377 {
 378     wxASSERT( IsOpened() );
 379
 380     int iRc = wxTell(m_fd);
 381     if ( iRc == -1 ) {
 382         wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
 383         return wxInvalidOffset;
 384     }
 385     else
 386         return (off_t)iRc;
 387 }
 388
 389 // get current file length
 390 off_t wxFile::Length() const
 391 {
 392     wxASSERT( IsOpened() );
 393
 394 #ifdef __VISUALC__
 395     int iRc = _filelength(m_fd);
 396 #else // !VC++
 397     int iRc = wxTell(m_fd);
 398     if ( iRc != -1 ) {
 399         // @ have to use const_cast :-(
 400         int iLen = ((wxFile *)this)->SeekEnd();
 401         if ( iLen != -1 ) {
 402             // restore old position
 403             if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
 404                 // error
 405                 iLen = -1;
 406             }
 407         }
 408
 409         iRc = iLen;
 410     }
 411 #endif  // VC++
 412
 413     if ( iRc == -1 ) {
 414         wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
 415         return wxInvalidOffset;
 416     }
 417     else
 418         return (off_t)iRc;
 419 }
 420
 421 // is end of file reached?
 422 bool wxFile::Eof() const
 423 {
 424     wxASSERT( IsOpened() );
 425
 426     int iRc;
 427
 428 #if defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
 429     // @@ this doesn't work, of course, on unseekable file descriptors
 430     off_t ofsCur = Tell(),
 431     ofsMax = Length();
 432     if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
 433         iRc = -1;
 434     else
 435         iRc = ofsCur == ofsMax;
 436 #else  // Windows and "native" compiler
 437     iRc = eof(m_fd);
 438 #endif // Windows/Unix
 439
 440     switch ( iRc ) {
 441         case 1:
 442             break;
 443
 444         case 0:
 445             return FALSE;
 446
 447         case -1:
 448             wxLogSysError(_("can't determine if the end of file is reached on 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     m_strTemp = wxFileName::CreateTempFileName(strName);
 475
 476     if ( m_strTemp.empty() )
 477     {
 478         // CreateTempFileName() failed
 479         return FALSE;
 480     }
 481
 482     // actually open the file now (it must already exist)
 483     if ( !m_file.Open(m_strTemp, wxFile::write) )
 484     {
 485         // opening existing file failed?
 486         return FALSE;
 487     }
 488
 489 #ifdef __UNIX__
 490     // the temp file should have the same permissions as the original one
 491     mode_t mode;
 492
 493     wxStructStat st;
 494     if ( stat(strName.fn_str(), &st) == 0 )
 495     {
 496         mode = st.st_mode;
 497     }
 498     else
 499     {
 500         // file probably didn't exist, just give it the default mode _using_
 501         // user's umask (new files creation should respect umask)
 502         mode_t mask = umask(0777);
 503         mode = 0666 & ~mask;
 504         umask(mask);
 505     }
 506
 507     if ( chmod(m_strTemp.mb_str(), mode) == -1 )
 508     {
 509         wxLogSysError(_("Failed to set temporary file permissions"));
 510     }
 511 #endif // Unix
 512
 513     return TRUE;
 514 }
 515
 516 // ----------------------------------------------------------------------------
 517 // destruction
 518 // ----------------------------------------------------------------------------
 519
 520 wxTempFile::~wxTempFile()
 521 {
 522     if ( IsOpened() )
 523         Discard();
 524 }
 525
 526 bool wxTempFile::Commit()
 527 {
 528     m_file.Close();
 529
 530     if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
 531         wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
 532         return FALSE;
 533     }
 534
 535     if ( wxRename(m_strTemp, m_strName) != 0 ) {
 536         wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
 537         return FALSE;
 538     }
 539
 540     return TRUE;
 541 }
 542
 543 void wxTempFile::Discard()
 544 {
 545     m_file.Close();
 546     if ( wxRemove(m_strTemp) != 0 )
 547         wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
 548 }
 549
 550 #endif // wxUSE_FILE
 551