1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: wxFile - encapsulates low-level "file descriptor"
4 // wxTempFile - safely replace the old file
5 // Author: Vadim Zeitlin
9 // Copyright: (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
10 // Licence: wxWindows license
11 /////////////////////////////////////////////////////////////////////////////
17 #pragma interface "file.h"
21 #include "wx/string.h"
22 #include "wx/filefn.h"
27 // ----------------------------------------------------------------------------
29 // ----------------------------------------------------------------------------
31 // we redefine these constants here because S_IREAD &c are _not_ standard
32 // however, we do assume that the values correspond to the Unix umask bits
33 #define wxS_IRUSR 00400
34 #define wxS_IWUSR 00200
35 #define wxS_IXUSR 00100
37 #define wxS_IRGRP 00040
38 #define wxS_IWGRP 00020
39 #define wxS_IXGRP 00010
41 #define wxS_IROTH 00004
42 #define wxS_IWOTH 00002
43 #define wxS_IXOTH 00001
45 // default mode for the new files: corresponds to umask 022
46 #define wxS_DEFAULT (wxS_IRUSR | wxS_IWUSR | wxS_IRGRP | wxS_IWGRP |\
47 wxS_IROTH | wxS_IWOTH)
49 // ----------------------------------------------------------------------------
50 // class wxFile: raw file IO
52 // NB: for space efficiency this class has no virtual functions, including
53 // dtor which is _not_ virtual, so it shouldn't be used as a base class.
54 // ----------------------------------------------------------------------------
55 class WXDLLEXPORT wxFile
58 // more file constants
59 // -------------------
61 enum OpenMode
{ read
, write
, read_write
, write_append
};
62 // standard values for file descriptor
63 enum { fd_invalid
= -1, fd_stdin
, fd_stdout
, fd_stderr
};
67 // check whether a regular file by this name exists
68 static bool Exists(const wxChar
*name
);
69 // check whetther we can access the given file in given mode
70 // (only read and write make sense here)
71 static bool Access(const wxChar
*name
, OpenMode mode
);
76 wxFile() { m_fd
= fd_invalid
; }
77 // open specified file (may fail, use IsOpened())
78 wxFile(const wxChar
*szFileName
, OpenMode mode
= read
);
79 // attach to (already opened) file
80 wxFile(int fd
) { m_fd
= fd
; }
83 // create a new file (with the default value of bOverwrite, it will fail if
84 // the file already exists, otherwise it will overwrite it and succeed)
85 bool Create(const wxChar
*szFileName
, bool bOverwrite
= FALSE
,
86 int access
= wxS_DEFAULT
);
87 bool Open(const wxChar
*szFileName
, OpenMode mode
= read
,
88 int access
= wxS_DEFAULT
);
89 bool Close(); // Close is a NOP if not opened
91 // assign an existing file descriptor and get it back from wxFile object
92 void Attach(int fd
) { Close(); m_fd
= fd
; }
93 void Detach() { m_fd
= fd_invalid
; }
94 int fd() const { return m_fd
; }
96 // read/write (unbuffered)
97 // returns number of bytes read or ofsInvalid on error
98 off_t
Read(void *pBuf
, off_t nCount
);
99 // returns the number of bytes written
100 size_t Write(const void *pBuf
, size_t nCount
);
101 // returns true on success
102 bool Write(const wxString
& s
, wxMBConv
& conv
= wxConvLibc
)
104 const wxWX2MBbuf buf
= s
.mb_str(conv
);
105 size_t size
= strlen(buf
);
106 return Write((const char *) buf
, size
) == size
;
108 // flush data not yet written
111 // file pointer operations (return ofsInvalid on failure)
112 // move ptr ofs bytes related to start/current off_t/end of file
113 off_t
Seek(off_t ofs
, wxSeekMode mode
= wxFromStart
);
114 // move ptr to ofs bytes before the end
115 off_t
SeekEnd(off_t ofs
= 0) { return Seek(ofs
, wxFromEnd
); }
118 // get current file length
119 off_t
Length() const;
123 bool IsOpened() const { return m_fd
!= fd_invalid
; }
124 // is end of file reached?
126 // has an error occured?
127 bool Error() const { return m_error
; }
129 // dtor closes the file if opened
130 ~wxFile() { Close(); }
133 // copy ctor and assignment operator are private because
134 // it doesn't make sense to copy files this way:
135 // attempt to do it will provoke a compile-time error.
136 wxFile(const wxFile
&);
137 wxFile
& operator=(const wxFile
&);
139 int m_fd
; // file descriptor or INVALID_FD if not opened
140 bool m_error
; // error memory
143 // ----------------------------------------------------------------------------
144 // class wxTempFile: if you want to replace another file, create an instance
145 // of wxTempFile passing the name of the file to be replaced to the ctor. Then
146 // you can write to wxTempFile and call Commit() function to replace the old
147 // file (and close this one) or call Discard() to cancel the modification. If
148 // you call neither of them, dtor will call Discard().
149 // ----------------------------------------------------------------------------
150 class WXDLLEXPORT wxTempFile
156 // associates the temp file with the file to be replaced and opens it
157 wxTempFile(const wxString
& strName
);
159 // open the temp file (strName is the name of file to be replaced)
160 bool Open(const wxString
& strName
);
162 // is the file opened?
163 bool IsOpened() const { return m_file
.IsOpened(); }
165 // I/O (both functions return true on success, false on failure)
166 bool Write(const void *p
, size_t n
) { return m_file
.Write(p
, n
) != 0; }
167 bool Write(const wxString
& str
, wxMBConv
& conv
= wxConvLibc
) { return m_file
.Write(str
, conv
); }
169 // different ways to close the file
170 // validate changes and delete the old file of name m_strName
175 // dtor calls Discard() if file is still opened
179 // no copy ctor/assignment operator
180 wxTempFile(const wxTempFile
&);
181 wxTempFile
& operator=(const wxTempFile
&);
183 wxString m_strName
, // name of the file to replace in Commit()
184 m_strTemp
; // temporary file name
185 wxFile m_file
; // the temporary file
190 #endif // _WX_FILEH__