wxWidgets/include/wx/file.h
Vadim Zeitlin 45ea509a21 common constants (wxSeekMode) and types (off_t) to wxFile and wxStream are
now defined in filefn.h included by both file.h and stream.h


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@270 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
1998-07-14 22:15:29 +00:00

155 lines
5.1 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: file.cpp
// Purpose: wxFile - encapsulates low-level "file descriptor"
// wxTempFile - safely replace the old file
// 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
/////////////////////////////////////////////////////////////////////////////
#ifndef __FILEH__
#define __FILEH__
#ifdef __GNUG__
#pragma interface "file.h"
#endif
#include "wx/string.h"
#include "wx/filefn.h"
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
// error return value for Seek() functions
const off_t ofsInvalid = (off_t)-1;
// ----------------------------------------------------------------------------
// class wxFile: raw file IO
//
// NB: for space efficiency this class has no virtual functions, including
// dtor which is _not_ virtual, so it shouldn't be used as a base class.
// ----------------------------------------------------------------------------
class WXDLLEXPORT wxFile
{
public:
// more file constants
// -------------------
// opening mode
enum OpenMode { read, write, read_write, write_append };
// standard values for file descriptor
enum { fd_invalid = -1, fd_stdin, fd_stdout, fd_stderr };
// static functions
// ----------------
static bool Exists(const char *sz); // also checks it's a regular file
// ctors
// -----
// def ctor
wxFile() { m_fd = fd_invalid; }
// open specified file (may fail, use IsOpened())
wxFile(const char *szFileName, OpenMode mode = read);
// attach to (already opened) file
wxFile(int fd) { m_fd = fd; }
// open/close
bool Create(const char *szFileName, bool bOverwrite = FALSE);
bool Open(const char *szFileName, OpenMode mode = read);
inline bool Close(); // Close is a NOP if not opened
// assign an existing file descriptor and get it back from wxFile object
void Attach(int fd) { Close(); m_fd = fd; }
void Detach() { m_fd = fd_invalid; }
int fd() const { return m_fd; }
// read/write (unbuffered)
// returns number of bytes read or ofsInvalid on error
off_t Read(void *pBuf, off_t nCount);
// returns true on success
uint Write(const void *pBuf, uint nCount);
// returns true on success
bool Write(const wxString& s) { return Write(s.c_str(), s.Len()) != 0; }
// flush data not yet written
bool Flush();
// file pointer operations (return ofsInvalid on failure)
// move ptr ofs bytes related to start/current off_t/end of file
off_t Seek(off_t ofs, wxSeekMode mode = wxFromStart);
// move ptr to ofs bytes before the end
off_t SeekEnd(off_t ofs = 0) { return Seek(ofs, wxFromEnd); }
// get current off_t
off_t Tell() const;
// get current file length
off_t Length() const;
// simple accessors
// is file opened?
bool IsOpened() const { return m_fd != fd_invalid; }
// is end of file reached?
bool Eof() const;
// is an error occured?
bool Error() const { return m_error; }
// dtor closes the file if opened
~wxFile();
private:
// copy ctor and assignment operator are private because
// it doesn't make sense to copy files this way:
// attempt to do it will provoke a compile-time error.
wxFile(const wxFile&);
wxFile& operator=(const wxFile&);
int m_fd; // file descriptor or INVALID_FD if not opened
bool m_error; // error memory
};
// ----------------------------------------------------------------------------
// class wxTempFile: if you want to replace another file, create an instance
// of wxTempFile passing the name of the file to be replaced to the ctor. Then
// you can write to wxTempFile and call Commit() function to replace the old
// file (and close this one) or call Discard() to cancel the modification. If
// you call neither of them, dtor will call Discard().
// ----------------------------------------------------------------------------
class wxTempFile
{
public:
// ctors
// default
wxTempFile() { }
// associates the temp file with the file to be replaced and opens it
wxTempFile(const wxString& strName);
// open the temp file (strName is the name of file to be replaced)
bool Open(const wxString& strName);
// is the file opened?
bool IsOpened() const { return m_file.IsOpened(); }
// I/O (both functions return true on success, false on failure)
bool Write(const void *p, uint n) { return m_file.Write(p, n) != 0; }
bool Write(const wxString& str) { return m_file.Write(str); }
// different ways to close the file
// validate changes and delete the old file of name m_strName
bool Commit();
// discard changes
void Discard();
// dtor calls Discard() if file is still opened
~wxTempFile();
private:
wxString m_strName, // name of the file to replace in Commit()
m_strTemp; // temporary file name
wxFile m_file; // the temporary file
};
#endif
// __FILEH__