src/common/file.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        file.cpp
// Purpose:     wxFile - encapsulates low-level "file descriptor"
//              wxTempFile
// Author:      Vadim Zeitlin
// Modified by:
// Created:     29/01/98
// RCS-ID:      $Id$
// Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

#ifdef __GNUG__
    #pragma implementation "file.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"
#include "wx/defs.h"

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

// standard
#if   defined(__WXMSW__) && !defined(__GNUWIN32__)
  #include  <io.h>

#ifndef __SALFORDC__
    #define   WIN32_LEAN_AND_MEAN
    #define   NOSERVICE
    #define   NOIME
    #define   NOATOM
    #define   NOGDI
    #define   NOGDICAPMASKS
    #define   NOMETAFILE
    #define   NOMINMAX
    #define   NOMSG
    #define   NOOPENFILE
    #define   NORASTEROPS
    #define   NOSCROLL
    #define   NOSOUND
    #define   NOSYSMETRICS
    #define   NOTEXTMETRIC
    #define   NOWH
    #define   NOCOMM
    #define   NOKANJI
    #define   NOCRYPT
    #define   NOMCX
#endif

    #include  <windows.h>     // for GetTempFileName
#elif (defined(__UNIX__) || defined(__GNUWIN32__))
    #include  <unistd.h>
    #ifdef __GNUWIN32__
        #include <windows.h>
    #endif
#elif (defined(__WXSTUBS__))
    // Have to ifdef this for different environments
    #include <io.h>
#elif (defined(__WXMAC__))
    int access( const char *path, int mode ) { return 0 ; }
    char* mktemp( char * path ) { return path ;}
    #include  <unistd.h>
    #include  <unix.h>
    #define   W_OK        2
    #define   R_OK        4
#else
    #error  "Please specify the header with file functions declarations."
#endif  //Win/UNIX

#include  <stdio.h>       // SEEK_xxx constants
#include  <fcntl.h>       // O_RDONLY &c

#ifndef __MWERKS__
    #include  <sys/types.h>   // needed for stat
    #include  <sys/stat.h>    // stat
#endif

// Microsoft compiler loves underscores, feed them to it
#ifdef  __VISUALC__
    // functions
    #define   open        _open
    #define   close       _close
    #define   read        _read
    #define   write       _write
    #define   lseek       _lseek
    #define   fsync       _commit
    #define   access      _access
    #define   eof         _eof

    // types
    #define   stat        _stat

    // constants

    #define   O_RDONLY    _O_RDONLY
    #define   O_WRONLY    _O_WRONLY
    #define   O_RDWR      _O_RDWR
    #define   O_EXCL      _O_EXCL
    #define   O_CREAT     _O_CREAT
    #define   O_BINARY    _O_BINARY

    #define   S_IFDIR     _S_IFDIR
    #define   S_IFREG     _S_IFREG
#else
    #define   tell(fd)    lseek(fd, 0, SEEK_CUR)
#endif  // VC++

#if defined(__BORLANDC__) || defined(_MSC_VER)
    #define   W_OK        2
    #define   R_OK        4
#endif

// there is no distinction between text and binary files under Unix
#ifdef    __UNIX__
    #define   O_BINARY    (0)
#endif  //__UNIX__

#ifdef __SALFORDC__
    #include <unix.h>
#endif

// wxWindows
#include  <wx/string.h>
#include  <wx/intl.h>
#include  <wx/file.h>
#include  <wx/log.h>

#ifndef MAX_PATH
    #define MAX_PATH 512
#endif

#ifdef __WXMAC__
    char gwxMacFileName[ MAX_PATH ] ;
    char gwxMacFileName2[ MAX_PATH ] ;
    char gwxMacFileName3[ MAX_PATH ] ;
#endif

// some broken compilers don't have 3rd argument in open() and creat()
#ifdef __SALFORDC__
    #define ACCESS(access)
    #define stat    _stat
#else // normal compiler
    #define ACCESS(access)  , (access)
#endif // Salford C

// ============================================================================
// implementation of wxFile
// ============================================================================

// ----------------------------------------------------------------------------
// static functions
// ----------------------------------------------------------------------------
bool wxFile::Exists(const wxChar *name)
{
    struct stat st;
#if wxUSE_UNICODE && wxMBFILES
    wxCharBuffer fname = wxConv_file.cWC2MB(name);

    return !access(fname, 0) &&
           !stat(MBSTRINGCAST fname, &st) &&
           (st.st_mode & S_IFREG);
#else
    return !access(name, 0) &&
           !stat((wxChar*) name, &st) &&
           (st.st_mode & S_IFREG);
#endif
}

bool wxFile::Access(const wxChar *name, OpenMode mode)
{
    int how = 0;

    switch ( mode ) {
        case read:
            how = R_OK;
            break;

        case write:
            how = W_OK;
            break;

        default:
            wxFAIL_MSG(_T("bad wxFile::Access mode parameter."));
    }

    return access(wxFNCONV(name), how) == 0;
}

// ----------------------------------------------------------------------------
// opening/closing
// ----------------------------------------------------------------------------

// ctors
wxFile::wxFile(const wxChar *szFileName, OpenMode mode)
{
    m_fd = fd_invalid;
    m_error = FALSE;

    Open(szFileName, mode);
}

// dtor
wxFile::~wxFile()
{
    Close();
}

// create the file, fail if it already exists and bOverwrite
bool wxFile::Create(const wxChar *szFileName, bool bOverwrite, int accessMode)
{
    // if bOverwrite we create a new file or truncate the existing one,
    // otherwise we only create the new file and fail if it already exists
    int fd = open(wxFNCONV(szFileName),
                  O_WRONLY | O_CREAT | (bOverwrite ? O_TRUNC : O_EXCL)
                  ACCESS(accessMode));

    if ( fd == -1 ) {
        wxLogSysError(_("can't create file '%s'"), szFileName);
        return FALSE;
    }
    else {
        Attach(fd);
        return TRUE;
    }
}

// open the file
bool wxFile::Open(const wxChar *szFileName, OpenMode mode, int accessMode)
{
    int flags = O_BINARY;

    switch ( mode ) {
        case read:
            flags |= O_RDONLY;
            break;

        case write:
            flags |= O_WRONLY | O_CREAT | O_TRUNC;
            break;

        case write_append:
            flags |= O_WRONLY | O_APPEND;
            break;

        case read_write:
            flags |= O_RDWR;
            break;
    }

    int fd = open(wxFNCONV(szFileName), flags ACCESS(accessMode));

    if ( fd == -1 ) {
        wxLogSysError(_("can't open file '%s'"), szFileName);
        return FALSE;
    }
    else {
        Attach(fd);
        return TRUE;
    }
}

// close
bool wxFile::Close()
{
    if ( IsOpened() ) {
        if ( close(m_fd) == -1 ) {
            wxLogSysError(_("can't close file descriptor %d"), m_fd);
            m_fd = fd_invalid;
            return FALSE;
        }
        else
            m_fd = fd_invalid;
    }

    return TRUE;
}

// ----------------------------------------------------------------------------
// read/write
// ----------------------------------------------------------------------------

// read
off_t wxFile::Read(void *pBuf, off_t nCount)
{
    wxCHECK( (pBuf != NULL) && IsOpened(), 0 );

#ifdef __MWERKS__
    int iRc = ::read(m_fd, (char*) pBuf, nCount);
#else
    int iRc = ::read(m_fd, pBuf, nCount);
#endif
    if ( iRc == -1 ) {
        wxLogSysError(_("can't read from file descriptor %d"), m_fd);
        return wxInvalidOffset;
    }
    else
        return (size_t)iRc;
}

// write
size_t wxFile::Write(const void *pBuf, size_t nCount)
{
    wxCHECK( (pBuf != NULL) && IsOpened(), 0 );

#ifdef __MWERKS__
    int iRc = ::write(m_fd, (const char*) pBuf, nCount);
#else
    int iRc = ::write(m_fd, pBuf, nCount);
#endif
    if ( iRc == -1 ) {
        wxLogSysError(_("can't write to file descriptor %d"), m_fd);
        m_error = TRUE;
        return 0;
    }
    else
        return iRc;
}

// flush
bool wxFile::Flush()
{
    if ( IsOpened() ) {
#if defined(__VISUALC__) || wxHAVE_FSYNC
        if ( fsync(m_fd) == -1 )
        {
            wxLogSysError(_("can't flush file descriptor %d"), m_fd);
            return FALSE;
        }
#else // no fsync
        // just do nothing
#endif // fsync
    }

    return TRUE;
}

// ----------------------------------------------------------------------------
// seek
// ----------------------------------------------------------------------------

// seek
off_t wxFile::Seek(off_t ofs, wxSeekMode mode)
{
    wxASSERT( IsOpened() );

    int flag = -1;
    switch ( mode ) {
        case wxFromStart:
            flag = SEEK_SET;
            break;

        case wxFromCurrent:
            flag = SEEK_CUR;
            break;

        case wxFromEnd:
            flag = SEEK_END;
            break;

        default:
            wxFAIL_MSG(_("unknown seek origin"));
    }

    int iRc = lseek(m_fd, ofs, flag);
    if ( iRc == -1 ) {
        wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
        return wxInvalidOffset;
    }
    else
        return (off_t)iRc;
}

// get current off_t
off_t wxFile::Tell() const
{
    wxASSERT( IsOpened() );

    int iRc = tell(m_fd);
    if ( iRc == -1 ) {
        wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
        return wxInvalidOffset;
    }
    else
        return (off_t)iRc;
}

// get current file length
off_t wxFile::Length() const
{
    wxASSERT( IsOpened() );

#ifdef __VISUALC__
    int iRc = _filelength(m_fd);
#else // !VC++
    int iRc = tell(m_fd);
    if ( iRc != -1 ) {
        // @ have to use const_cast :-(
        int iLen = ((wxFile *)this)->SeekEnd();
        if ( iLen != -1 ) {
            // restore old position
            if ( ((wxFile *)this)->Seek(iRc) == -1 ) {
                // error
                iLen = -1;
            }
        }

        iRc = iLen;
    }
#endif  // VC++

    if ( iRc == -1 ) {
        wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
        return wxInvalidOffset;
    }
    else
        return (off_t)iRc;
}

// is end of file reached?
bool wxFile::Eof() const
{
    wxASSERT( IsOpened() );

    int iRc;

#if defined(__UNIX__) || defined(__GNUWIN32__) || defined( __MWERKS__ ) || defined(__SALFORDC__)
    // @@ this doesn't work, of course, on unseekable file descriptors
    off_t ofsCur = Tell(),
    ofsMax = Length();
    if ( ofsCur == wxInvalidOffset || ofsMax == wxInvalidOffset )
        iRc = -1;
    else
        iRc = ofsCur == ofsMax;
#else  // Windows and "native" compiler
    iRc = eof(m_fd);
#endif // Windows/Unix

    switch ( iRc ) {
        case 1:
            break;

        case 0:
            return FALSE;

        case -1:
            wxLogSysError(_("can't determine if the end of file is reached on \
                descriptor %d"), m_fd);
                break;

        default:
            wxFAIL_MSG(_("invalid eof() return value."));
    }

    return TRUE;
}

// ============================================================================
// implementation of wxTempFile
// ============================================================================

// ----------------------------------------------------------------------------
// construction
// ----------------------------------------------------------------------------
wxTempFile::wxTempFile(const wxString& strName)
{
    Open(strName);
}

bool wxTempFile::Open(const wxString& strName)
{
    m_strName = strName;

    // we want to create the file in the same directory as strName because
    // otherwise rename() in Commit() might not work (if the files are on
    // different partitions for example). Unfortunately, the only standard
    // (POSIX) temp file creation function tmpnam() can't do it.
#if defined(__UNIX__) || defined(__WXSTUBS__)|| defined( __WXMAC__ )
    static const wxChar *szMktempSuffix = _T("XXXXXX");
    m_strTemp << strName << szMktempSuffix;
    mktemp(MBSTRINGCAST m_strTemp.mb_str()); // will do because length doesn't change
#else // Windows
    wxString strPath;
    wxSplitPath(strName, &strPath, NULL, NULL);
    if ( strPath.IsEmpty() )
        strPath = _T('.');  // GetTempFileName will fail if we give it empty string
#ifdef __WIN32__
    if ( !GetTempFileName(strPath, _T("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
#else
        // Not sure why MSVC++ 1.5 header defines first param as BYTE - bug?
        if ( !GetTempFileName((BYTE) (const wxChar*) strPath, _T("wx_"),0, m_strTemp.GetWriteBuf(MAX_PATH)) )
#endif
            wxLogLastError(_T("GetTempFileName"));
    m_strTemp.UngetWriteBuf();
#endif  // Windows/Unix

    int access = wxS_DEFAULT;
#ifdef __UNIX__
    // create the file with the same mode as the original one under Unix
    mode_t umaskOld;
    bool changedUmask;

    struct stat st;
    if ( stat(strName.fn_str(), &st) == 0 )
    {
        // this assumes that only lower bits of st_mode contain the access
        // rights, but it's true for at least all Unices which have S_IXXXX()
        // macros, so should not be less portable than using (not POSIX)
        // S_IFREG &c
        access = st.st_mode & 0777;

        // we want to create the file with exactly the same access rights as
        // the original one, so disable the user's umask for the moment
        umaskOld = umask(0);
        changedUmask = TRUE;
    }
    else
    {
        // file probably didn't exist, just create with default mode _using_
        // user's umask (new files creation should respet umask)
        changedUmask = TRUE;
    }
#endif // Unix

    bool ok =  m_file.Open(m_strTemp, wxFile::write, access);

#ifdef __UNIX__
    if ( changedUmask )
    {
        // restore umask now that the file is created
        (void)umask(umaskOld);
    }
#endif // Unix

    return ok;
}

// ----------------------------------------------------------------------------
// destruction
// ----------------------------------------------------------------------------

wxTempFile::~wxTempFile()
{
    if ( IsOpened() )
        Discard();
}

bool wxTempFile::Commit()
{
    m_file.Close();

    if ( wxFile::Exists(m_strName) && remove(m_strName.fn_str()) != 0 ) {
        wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
        return FALSE;
    }

    if ( rename(m_strTemp.fn_str(), m_strName.fn_str()) != 0 ) {
        wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
        return FALSE;
    }

    return TRUE;
}

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