src/common/file.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        src/common/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 licence
/////////////////////////////////////////////////////////////////////////////

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

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

#ifdef __BORLANDC__
  #pragma hdrstop
#endif

#if wxUSE_FILE

// standard
#if defined(__WINDOWS__) && !defined(__GNUWIN32__) && !defined(__WXMICROWIN__) && !defined(__WXWINCE__)

#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

#elif defined(__WINDOWS__) && defined(__WXWINCE__)
    #include  "wx/msw/missing.h"
#elif (defined(__OS2__))
    #include <io.h>
#elif (defined(__UNIX__) || defined(__GNUWIN32__))
    #include  <unistd.h>
    #include  <time.h>
    #include  <sys/stat.h>
    #ifdef __GNUWIN32__
        #include "wx/msw/wrapwin.h"
    #endif
#elif defined(__DOS__)
    #if defined(__WATCOMC__)
       #include <io.h>
    #elif defined(__DJGPP__)
       #include <io.h>
       #include <unistd.h>
       #include <stdio.h>
    #else
        #error  "Please specify the header with file functions declarations."
    #endif
#elif (defined(__WXSTUBS__))
    // Have to ifdef this for different environments
    #include <io.h>
#elif (defined(__WXMAC__))
#if __MSL__ < 0x6000
    int access( const char *path, int mode ) { return 0 ; }
#else
    int _access( const char *path, int mode ) { return 0 ; }
#endif
    char* mktemp( char * path ) { return path ;}
    #include <stat.h>
    #include <unistd.h>
#else
    #error  "Please specify the header with file functions declarations."
#endif  //Win/UNIX

#include  <stdio.h>       // SEEK_xxx constants

#ifndef __WXWINCE__
    #include <errno.h>
#endif

// Windows compilers don't have these constants
#ifndef W_OK
    enum
    {
        F_OK = 0,   // test for existence
        X_OK = 1,   //          execute permission
        W_OK = 2,   //          write
        R_OK = 4    //          read
    };
#endif // W_OK

// wxWidgets
#ifndef WX_PRECOMP
    #include  "wx/string.h"
    #include  "wx/intl.h"
    #include  "wx/log.h"
    #include "wx/crt.h"
#endif // !WX_PRECOMP

#include  "wx/filename.h"
#include  "wx/file.h"
#include  "wx/filefn.h"

// there is no distinction between text and binary files under Unix, so define
// O_BINARY as 0 if the system headers don't do it already
#if defined(__UNIX__) && !defined(O_BINARY)
    #define   O_BINARY    (0)
#endif  //__UNIX__

#ifdef __WINDOWS__
    #include "wx/msw/mslu.h"
#endif

#ifdef __WXWINCE__
    #include "wx/msw/private.h"
#endif

#ifndef MAX_PATH
    #define MAX_PATH 512
#endif

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

// ----------------------------------------------------------------------------
// static functions
// ----------------------------------------------------------------------------

bool wxFile::Exists(const wxString& name)
{
    return wxFileExists(name);
}

bool wxFile::Access(const wxString& name, OpenMode mode)
{
    int how;

    switch ( mode )
    {
        default:
            wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
            // fall through

        case read:
            how = R_OK;
            break;

        case write:
            how = W_OK;
            break;

        case read_write:
            how = R_OK | W_OK;
            break;
    }

    return wxAccess(name, how) == 0;
}

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

// ctors
wxFile::wxFile(const wxString& fileName, OpenMode mode)
{
    m_fd = fd_invalid;
    m_lasterror = 0;

    Open(fileName, mode);
}

bool wxFile::CheckForError(wxFileOffset rc) const
{
    if ( rc != -1 )
        return false;

    const_cast<wxFile *>(this)->m_lasterror =
#ifndef __WXWINCE__
                                                errno
#else
                                                ::GetLastError()
#endif
                                                ;

    return true;
}

// create the file, fail if it already exists and bOverwrite
bool wxFile::Create(const wxString& fileName, 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 = wxOpen( fileName,
                     O_BINARY | O_WRONLY | O_CREAT |
                     (bOverwrite ? O_TRUNC : O_EXCL),
                     accessMode );
    if ( CheckForError(fd) )
    {
        wxLogSysError(_("can't create file '%s'"), fileName);
        return false;
    }

    Attach(fd);
    return true;
}

// open the file
bool wxFile::Open(const wxString& fileName, OpenMode mode, int accessMode)
{
    int flags = O_BINARY;

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

        case write_append:
            if ( wxFile::Exists(fileName) )
            {
                flags |= O_WRONLY | O_APPEND;
                break;
            }
            //else: fall through as write_append is the same as write if the
            //      file doesn't exist

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

        case write_excl:
            flags |= O_WRONLY | O_CREAT | O_EXCL;
            break;

        case read_write:
            flags |= O_RDWR;
            break;
    }

#ifdef __WINDOWS__
    // only read/write bits for "all" are supported by this function under
    // Windows, and VC++ 8 returns EINVAL if any other bits are used in
    // accessMode, so clear them as they have at best no effect anyhow
    accessMode &= wxS_IRUSR | wxS_IWUSR;
#endif // __WINDOWS__

    int fd = wxOpen( fileName, flags, accessMode);

    if ( CheckForError(fd) )
    {
        wxLogSysError(_("can't open file '%s'"), fileName);
        return false;
    }

    Attach(fd);
    return true;
}

// close
bool wxFile::Close()
{
    if ( IsOpened() ) {
        if ( CheckForError(wxClose(m_fd)) )
        {
            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
ssize_t wxFile::Read(void *pBuf, size_t nCount)
{
    wxCHECK( (pBuf != NULL) && IsOpened(), 0 );

    ssize_t iRc = wxRead(m_fd, pBuf, nCount);

    if ( CheckForError(iRc) )
    {
        wxLogSysError(_("can't read from file descriptor %d"), m_fd);
        return wxInvalidOffset;
    }

    return iRc;
}

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

    ssize_t iRc = wxWrite(m_fd, pBuf, nCount);

    if ( CheckForError(iRc) )
    {
        wxLogSysError(_("can't write to file descriptor %d"), m_fd);
        iRc = 0;
    }

    return iRc;
}

bool wxFile::Write(const wxString& s, const wxMBConv& conv)
{
  const wxWX2MBbuf buf = s.mb_str(conv);
  if ( !buf )
      return false;

#if wxUSE_UNICODE
  const size_t size = buf.length();
#else
  const size_t size = s.length();
#endif

  return Write(buf, size) == size;
}

// flush
bool wxFile::Flush()
{
#ifdef HAVE_FSYNC
    // fsync() only works on disk files and returns errors for pipes, don't
    // call it then
    if ( IsOpened() && GetKind() == wxFILE_KIND_DISK )
    {
        if ( CheckForError(wxFsync(m_fd)) )
        {
            wxLogSysError(_("can't flush file descriptor %d"), m_fd);
            return false;
        }
    }
#endif // HAVE_FSYNC

    return true;
}

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

// seek
wxFileOffset wxFile::Seek(wxFileOffset ofs, wxSeekMode mode)
{
    wxASSERT_MSG( IsOpened(), wxT("can't seek on closed file") );
    wxCHECK_MSG( ofs != wxInvalidOffset || mode != wxFromStart,
                 wxInvalidOffset,
                 wxT("invalid absolute file offset") );

    int origin;
    switch ( mode ) {
        default:
            wxFAIL_MSG(wxT("unknown seek origin"));

        case wxFromStart:
            origin = SEEK_SET;
            break;

        case wxFromCurrent:
            origin = SEEK_CUR;
            break;

        case wxFromEnd:
            origin = SEEK_END;
            break;
    }

    wxFileOffset iRc = wxSeek(m_fd, ofs, origin);
    if ( CheckForError(iRc) )
    {
        wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
    }

    return iRc;
}

// get current file offset
wxFileOffset wxFile::Tell() const
{
    wxASSERT( IsOpened() );

    wxFileOffset iRc = wxTell(m_fd);
    if ( CheckForError(iRc) )
    {
        wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
    }

    return iRc;
}

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

    // we use a special method for Linux systems where files in sysfs (i.e.
    // those under /sys typically) return length of 4096 bytes even when
    // they're much smaller -- this is a problem as it results in errors later
    // when we try reading 4KB from them
#ifdef __LINUX__
    struct stat st;
    if ( fstat(m_fd, &st) == 0 )
    {
        // returning 0 for the special files indicates to the caller that they
        // are not seekable
        return st.st_blocks ? st.st_size : 0;
    }
    //else: failed to stat, try the normal method
#endif // __LINUX__

    wxFileOffset iRc = Tell();
    if ( iRc != wxInvalidOffset ) {
        wxFileOffset iLen = const_cast<wxFile *>(this)->SeekEnd();
        if ( iLen != wxInvalidOffset ) {
            // restore old position
            if ( ((wxFile *)this)->Seek(iRc) == wxInvalidOffset ) {
                // error
                iLen = wxInvalidOffset;
            }
        }

        iRc = iLen;
    }

    if ( iRc == wxInvalidOffset )
    {
        // last error was already set by Tell()
        wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
    }

    return iRc;
}

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

    wxFileOffset iRc;

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

    if ( iRc == 0 )
        return false;

    if ( iRc == wxInvalidOffset )
    {
        wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
    }
    else if ( iRc != 1 )
    {
        wxFAIL_MSG(wxT("invalid eof() return value."));
    }

    return true;
}

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

// ----------------------------------------------------------------------------
// construction
// ----------------------------------------------------------------------------

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

bool wxTempFile::Open(const wxString& strName)
{
    // we must have an absolute filename because otherwise CreateTempFileName()
    // would create the temp file in $TMP (i.e. the system standard location
    // for the temp files) which might be on another volume/drive/mount and
    // wxRename()ing it later to m_strName from Commit() would then fail
    //
    // with the absolute filename, the temp file is created in the same
    // directory as this one which ensures that wxRename() may work later
    wxFileName fn(strName);
    if ( !fn.IsAbsolute() )
    {
        fn.Normalize(wxPATH_NORM_ABSOLUTE);
    }

    m_strName = fn.GetFullPath();

    m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);

    if ( m_strTemp.empty() )
    {
        // CreateTempFileName() failed
        return false;
    }

#ifdef __UNIX__
    // the temp file should have the same permissions as the original one
    mode_t mode;

    wxStructStat st;
    if ( stat( (const char*) m_strName.fn_str(), &st) == 0 )
    {
        mode = st.st_mode;
    }
    else
    {
        // file probably didn't exist, just give it the default mode _using_
        // user's umask (new files creation should respect umask)
        mode_t mask = umask(0777);
        mode = 0666 & ~mask;
        umask(mask);
    }

    if ( chmod( (const char*) m_strTemp.fn_str(), mode) == -1 )
    {
#ifndef __OS2__
        wxLogSysError(_("Failed to set temporary file permissions"));
#endif
    }
#endif // Unix

    return true;
}

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

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

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

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

    if ( !wxRenameFile(m_strTemp, m_strName)  ) {
        wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
        return false;
    }

    return true;
}

void wxTempFile::Discard()
{
    m_file.Close();
    if ( wxRemove(m_strTemp) != 0 )
    {
        wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
    }
}

#endif // wxUSE_FILE
Commit	Line	Data
	1	/////////////////////////////////////////////////////////////////////////////
	2	// Name: src/common/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 licence
	11	/////////////////////////////////////////////////////////////////////////////
	12
	13	// ----------------------------------------------------------------------------
	14	// headers
	15	// ----------------------------------------------------------------------------
	16
	17	// For compilers that support precompilation, includes "wx.h".
	18	#include "wx/wxprec.h"
	19
	20	#ifdef __BORLANDC__
	21	#pragma hdrstop
	22	#endif
	23
	24	#if wxUSE_FILE
	25
	26	// standard
	27	#if defined(__WINDOWS__) && !defined(__GNUWIN32__) && !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
	28
	29	#define WIN32_LEAN_AND_MEAN
	30	#define NOSERVICE
	31	#define NOIME
	32	#define NOATOM
	33	#define NOGDI
	34	#define NOGDICAPMASKS
	35	#define NOMETAFILE
	36	#define NOMINMAX
	37	#define NOMSG
	38	#define NOOPENFILE
	39	#define NORASTEROPS
	40	#define NOSCROLL
	41	#define NOSOUND
	42	#define NOSYSMETRICS
	43	#define NOTEXTMETRIC
	44	#define NOWH
	45	#define NOCOMM
	46	#define NOKANJI
	47	#define NOCRYPT
	48	#define NOMCX
	49
	50	#elif defined(__WINDOWS__) && defined(__WXWINCE__)
	51	#include "wx/msw/missing.h"
	52	#elif (defined(__OS2__))
	53	#include <io.h>
	54	#elif (defined(__UNIX__) \|\| defined(__GNUWIN32__))
	55	#include <unistd.h>
	56	#include <time.h>
	57	#include <sys/stat.h>
	58	#ifdef __GNUWIN32__
	59	#include "wx/msw/wrapwin.h"
	60	#endif
	61	#elif defined(__DOS__)
	62	#if defined(__WATCOMC__)
	63	#include <io.h>
	64	#elif defined(__DJGPP__)
	65	#include <io.h>
	66	#include <unistd.h>
	67	#include <stdio.h>
	68	#else
	69	#error "Please specify the header with file functions declarations."
	70	#endif
	71	#elif (defined(__WXSTUBS__))
	72	// Have to ifdef this for different environments
	73	#include <io.h>
	74	#elif (defined(__WXMAC__))
	75	#if __MSL__ < 0x6000
	76	int access( const char *path, int mode ) { return 0 ; }
	77	#else
	78	int _access( const char *path, int mode ) { return 0 ; }
	79	#endif
	80	char* mktemp( char * path ) { return path ;}
	81	#include <stat.h>
	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
	89	#ifndef __WXWINCE__
	90	#include <errno.h>
	91	#endif
	92
	93	// Windows compilers don't have these constants
	94	#ifndef W_OK
	95	enum
	96	{
	97	F_OK = 0, // test for existence
	98	X_OK = 1, // execute permission
	99	W_OK = 2, // write
	100	R_OK = 4 // read
	101	};
	102	#endif // W_OK
	103
	104	// wxWidgets
	105	#ifndef WX_PRECOMP
	106	#include "wx/string.h"
	107	#include "wx/intl.h"
	108	#include "wx/log.h"
	109	#include "wx/crt.h"
	110	#endif // !WX_PRECOMP
	111
	112	#include "wx/filename.h"
	113	#include "wx/file.h"
	114	#include "wx/filefn.h"
	115
	116	// there is no distinction between text and binary files under Unix, so define
	117	// O_BINARY as 0 if the system headers don't do it already
	118	#if defined(__UNIX__) && !defined(O_BINARY)
	119	#define O_BINARY (0)
	120	#endif //__UNIX__
	121
	122	#ifdef __WINDOWS__
	123	#include "wx/msw/mslu.h"
	124	#endif
	125
	126	#ifdef __WXWINCE__
	127	#include "wx/msw/private.h"
	128	#endif
	129
	130	#ifndef MAX_PATH
	131	#define MAX_PATH 512
	132	#endif
	133
	134	// ============================================================================
	135	// implementation of wxFile
	136	// ============================================================================
	137
	138	// ----------------------------------------------------------------------------
	139	// static functions
	140	// ----------------------------------------------------------------------------
	141
	142	bool wxFile::Exists(const wxString& name)
	143	{
	144	return wxFileExists(name);
	145	}
	146
	147	bool wxFile::Access(const wxString& name, OpenMode mode)
	148	{
	149	int how;
	150
	151	switch ( mode )
	152	{
	153	default:
	154	wxFAIL_MSG(wxT("bad wxFile::Access mode parameter."));
	155	// fall through
	156
	157	case read:
	158	how = R_OK;
	159	break;
	160
	161	case write:
	162	how = W_OK;
	163	break;
	164
	165	case read_write:
	166	how = R_OK \| W_OK;
	167	break;
	168	}
	169
	170	return wxAccess(name, how) == 0;
	171	}
	172
	173	// ----------------------------------------------------------------------------
	174	// opening/closing
	175	// ----------------------------------------------------------------------------
	176
	177	// ctors
	178	wxFile::wxFile(const wxString& fileName, OpenMode mode)
	179	{
	180	m_fd = fd_invalid;
	181	m_lasterror = 0;
	182
	183	Open(fileName, mode);
	184	}
	185
	186	bool wxFile::CheckForError(wxFileOffset rc) const
	187	{
	188	if ( rc != -1 )
	189	return false;
	190
	191	const_cast<wxFile *>(this)->m_lasterror =
	192	#ifndef __WXWINCE__
	193	errno
	194	#else
	195	::GetLastError()
	196	#endif
	197	;
	198
	199	return true;
	200	}
	201
	202	// create the file, fail if it already exists and bOverwrite
	203	bool wxFile::Create(const wxString& fileName, bool bOverwrite, int accessMode)
	204	{
	205	// if bOverwrite we create a new file or truncate the existing one,
	206	// otherwise we only create the new file and fail if it already exists
	207	int fd = wxOpen( fileName,
	208	O_BINARY \| O_WRONLY \| O_CREAT \|
	209	(bOverwrite ? O_TRUNC : O_EXCL),
	210	accessMode );
	211	if ( CheckForError(fd) )
	212	{
	213	wxLogSysError(_("can't create file '%s'"), fileName);
	214	return false;
	215	}
	216
	217	Attach(fd);
	218	return true;
	219	}
	220
	221	// open the file
	222	bool wxFile::Open(const wxString& fileName, OpenMode mode, int accessMode)
	223	{
	224	int flags = O_BINARY;
	225
	226	switch ( mode )
	227	{
	228	case read:
	229	flags \|= O_RDONLY;
	230	break;
	231
	232	case write_append:
	233	if ( wxFile::Exists(fileName) )
	234	{
	235	flags \|= O_WRONLY \| O_APPEND;
	236	break;
	237	}
	238	//else: fall through as write_append is the same as write if the
	239	// file doesn't exist
	240
	241	case write:
	242	flags \|= O_WRONLY \| O_CREAT \| O_TRUNC;
	243	break;
	244
	245	case write_excl:
	246	flags \|= O_WRONLY \| O_CREAT \| O_EXCL;
	247	break;
	248
	249	case read_write:
	250	flags \|= O_RDWR;
	251	break;
	252	}
	253
	254	#ifdef __WINDOWS__
	255	// only read/write bits for "all" are supported by this function under
	256	// Windows, and VC++ 8 returns EINVAL if any other bits are used in
	257	// accessMode, so clear them as they have at best no effect anyhow
	258	accessMode &= wxS_IRUSR \| wxS_IWUSR;
	259	#endif // __WINDOWS__
	260
	261	int fd = wxOpen( fileName, flags, accessMode);
	262
	263	if ( CheckForError(fd) )
	264	{
	265	wxLogSysError(_("can't open file '%s'"), fileName);
	266	return false;
	267	}
	268
	269	Attach(fd);
	270	return true;
	271	}
	272
	273	// close
	274	bool wxFile::Close()
	275	{
	276	if ( IsOpened() ) {
	277	if ( CheckForError(wxClose(m_fd)) )
	278	{
	279	wxLogSysError(_("can't close file descriptor %d"), m_fd);
	280	m_fd = fd_invalid;
	281	return false;
	282	}
	283	else
	284	m_fd = fd_invalid;
	285	}
	286
	287	return true;
	288	}
	289
	290	// ----------------------------------------------------------------------------
	291	// read/write
	292	// ----------------------------------------------------------------------------
	293
	294	// read
	295	ssize_t wxFile::Read(void *pBuf, size_t nCount)
	296	{
	297	wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
	298
	299	ssize_t iRc = wxRead(m_fd, pBuf, nCount);
	300
	301	if ( CheckForError(iRc) )
	302	{
	303	wxLogSysError(_("can't read from file descriptor %d"), m_fd);
	304	return wxInvalidOffset;
	305	}
	306
	307	return iRc;
	308	}
	309
	310	// write
	311	size_t wxFile::Write(const void *pBuf, size_t nCount)
	312	{
	313	wxCHECK( (pBuf != NULL) && IsOpened(), 0 );
	314
	315	ssize_t iRc = wxWrite(m_fd, pBuf, nCount);
	316
	317	if ( CheckForError(iRc) )
	318	{
	319	wxLogSysError(_("can't write to file descriptor %d"), m_fd);
	320	iRc = 0;
	321	}
	322
	323	return iRc;
	324	}
	325
	326	bool wxFile::Write(const wxString& s, const wxMBConv& conv)
	327	{
	328	const wxWX2MBbuf buf = s.mb_str(conv);
	329	if ( !buf )
	330	return false;
	331
	332	#if wxUSE_UNICODE
	333	const size_t size = buf.length();
	334	#else
	335	const size_t size = s.length();
	336	#endif
	337
	338	return Write(buf, size) == size;
	339	}
	340
	341	// flush
	342	bool wxFile::Flush()
	343	{
	344	#ifdef HAVE_FSYNC
	345	// fsync() only works on disk files and returns errors for pipes, don't
	346	// call it then
	347	if ( IsOpened() && GetKind() == wxFILE_KIND_DISK )
	348	{
	349	if ( CheckForError(wxFsync(m_fd)) )
	350	{
	351	wxLogSysError(_("can't flush file descriptor %d"), m_fd);
	352	return false;
	353	}
	354	}
	355	#endif // HAVE_FSYNC
	356
	357	return true;
	358	}
	359
	360	// ----------------------------------------------------------------------------
	361	// seek
	362	// ----------------------------------------------------------------------------
	363
	364	// seek
	365	wxFileOffset wxFile::Seek(wxFileOffset ofs, wxSeekMode mode)
	366	{
	367	wxASSERT_MSG( IsOpened(), wxT("can't seek on closed file") );
	368	wxCHECK_MSG( ofs != wxInvalidOffset \|\| mode != wxFromStart,
	369	wxInvalidOffset,
	370	wxT("invalid absolute file offset") );
	371
	372	int origin;
	373	switch ( mode ) {
	374	default:
	375	wxFAIL_MSG(wxT("unknown seek origin"));
	376
	377	case wxFromStart:
	378	origin = SEEK_SET;
	379	break;
	380
	381	case wxFromCurrent:
	382	origin = SEEK_CUR;
	383	break;
	384
	385	case wxFromEnd:
	386	origin = SEEK_END;
	387	break;
	388	}
	389
	390	wxFileOffset iRc = wxSeek(m_fd, ofs, origin);
	391	if ( CheckForError(iRc) )
	392	{
	393	wxLogSysError(_("can't seek on file descriptor %d"), m_fd);
	394	}
	395
	396	return iRc;
	397	}
	398
	399	// get current file offset
	400	wxFileOffset wxFile::Tell() const
	401	{
	402	wxASSERT( IsOpened() );
	403
	404	wxFileOffset iRc = wxTell(m_fd);
	405	if ( CheckForError(iRc) )
	406	{
	407	wxLogSysError(_("can't get seek position on file descriptor %d"), m_fd);
	408	}
	409
	410	return iRc;
	411	}
	412
	413	// get current file length
	414	wxFileOffset wxFile::Length() const
	415	{
	416	wxASSERT( IsOpened() );
	417
	418	// we use a special method for Linux systems where files in sysfs (i.e.
	419	// those under /sys typically) return length of 4096 bytes even when
	420	// they're much smaller -- this is a problem as it results in errors later
	421	// when we try reading 4KB from them
	422	#ifdef __LINUX__
	423	struct stat st;
	424	if ( fstat(m_fd, &st) == 0 )
	425	{
	426	// returning 0 for the special files indicates to the caller that they
	427	// are not seekable
	428	return st.st_blocks ? st.st_size : 0;
	429	}
	430	//else: failed to stat, try the normal method
	431	#endif // __LINUX__
	432
	433	wxFileOffset iRc = Tell();
	434	if ( iRc != wxInvalidOffset ) {
	435	wxFileOffset iLen = const_cast<wxFile *>(this)->SeekEnd();
	436	if ( iLen != wxInvalidOffset ) {
	437	// restore old position
	438	if ( ((wxFile *)this)->Seek(iRc) == wxInvalidOffset ) {
	439	// error
	440	iLen = wxInvalidOffset;
	441	}
	442	}
	443
	444	iRc = iLen;
	445	}
	446
	447	if ( iRc == wxInvalidOffset )
	448	{
	449	// last error was already set by Tell()
	450	wxLogSysError(_("can't find length of file on file descriptor %d"), m_fd);
	451	}
	452
	453	return iRc;
	454	}
	455
	456	// is end of file reached?
	457	bool wxFile::Eof() const
	458	{
	459	wxASSERT( IsOpened() );
	460
	461	wxFileOffset iRc;
	462
	463	#if defined(__DOS__) \|\| defined(__UNIX__) \|\| defined(__GNUWIN32__)
	464	// @@ this doesn't work, of course, on unseekable file descriptors
	465	wxFileOffset ofsCur = Tell(),
	466	ofsMax = Length();
	467	if ( ofsCur == wxInvalidOffset \|\| ofsMax == wxInvalidOffset )
	468	iRc = wxInvalidOffset;
	469	else
	470	iRc = ofsCur == ofsMax;
	471	#else // Windows and "native" compiler
	472	iRc = wxEof(m_fd);
	473	#endif // Windows/Unix
	474
	475	if ( iRc == 0 )
	476	return false;
	477
	478	if ( iRc == wxInvalidOffset )
	479	{
	480	wxLogSysError(_("can't determine if the end of file is reached on descriptor %d"), m_fd);
	481	}
	482	else if ( iRc != 1 )
	483	{
	484	wxFAIL_MSG(wxT("invalid eof() return value."));
	485	}
	486
	487	return true;
	488	}
	489
	490	// ============================================================================
	491	// implementation of wxTempFile
	492	// ============================================================================
	493
	494	// ----------------------------------------------------------------------------
	495	// construction
	496	// ----------------------------------------------------------------------------
	497
	498	wxTempFile::wxTempFile(const wxString& strName)
	499	{
	500	Open(strName);
	501	}
	502
	503	bool wxTempFile::Open(const wxString& strName)
	504	{
	505	// we must have an absolute filename because otherwise CreateTempFileName()
	506	// would create the temp file in $TMP (i.e. the system standard location
	507	// for the temp files) which might be on another volume/drive/mount and
	508	// wxRename()ing it later to m_strName from Commit() would then fail
	509	//
	510	// with the absolute filename, the temp file is created in the same
	511	// directory as this one which ensures that wxRename() may work later
	512	wxFileName fn(strName);
	513	if ( !fn.IsAbsolute() )
	514	{
	515	fn.Normalize(wxPATH_NORM_ABSOLUTE);
	516	}
	517
	518	m_strName = fn.GetFullPath();
	519
	520	m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);
	521
	522	if ( m_strTemp.empty() )
	523	{
	524	// CreateTempFileName() failed
	525	return false;
	526	}
	527
	528	#ifdef __UNIX__
	529	// the temp file should have the same permissions as the original one
	530	mode_t mode;
	531
	532	wxStructStat st;
	533	if ( stat( (const char*) m_strName.fn_str(), &st) == 0 )
	534	{
	535	mode = st.st_mode;
	536	}
	537	else
	538	{
	539	// file probably didn't exist, just give it the default mode _using_
	540	// user's umask (new files creation should respect umask)
	541	mode_t mask = umask(0777);
	542	mode = 0666 & ~mask;
	543	umask(mask);
	544	}
	545
	546	if ( chmod( (const char*) m_strTemp.fn_str(), mode) == -1 )
	547	{
	548	#ifndef __OS2__
	549	wxLogSysError(_("Failed to set temporary file permissions"));
	550	#endif
	551	}
	552	#endif // Unix
	553
	554	return true;
	555	}
	556
	557	// ----------------------------------------------------------------------------
	558	// destruction
	559	// ----------------------------------------------------------------------------
	560
	561	wxTempFile::~wxTempFile()
	562	{
	563	if ( IsOpened() )
	564	Discard();
	565	}
	566
	567	bool wxTempFile::Commit()
	568	{
	569	m_file.Close();
	570
	571	if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
	572	wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
	573	return false;
	574	}
	575
	576	if ( !wxRenameFile(m_strTemp, m_strName) ) {
	577	wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
	578	return false;
	579	}
	580
	581	return true;
	582	}
	583
	584	void wxTempFile::Discard()
	585	{
	586	m_file.Close();
	587	if ( wxRemove(m_strTemp) != 0 )
	588	{
	589	wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
	590	}
	591	}
	592
	593	#endif // wxUSE_FILE
	594