1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 %% Purpose: wxFFile documentation
4 %% Author: Vadim Zeitlin
6 %% Created: 14.01.02 (extracted from file.tex)
8 %% Copyright: (c) Vadim Zeitlin
9 %% License: wxWidgets license
10 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
12 \section{\class{wxFFile
}}\label{wxffile
}
14 wxFFile implements buffered file I/O. This is a very small class designed to
15 minimize the overhead of using it - in fact, there is hardly any overhead at
16 all, but using it brings you automatic error checking and hides differences
17 between platforms and compilers. It wraps inside it a
{\tt FILE *
} handle used
18 by standard C IO library (also known as
{\tt stdio
}).
20 \wxheading{Derived from
}
24 \wxheading{Include files
}
29 \begin{twocollist
}\itemsep=
0pt
%
30 \twocolitem{{\bf wxFromStart
}}{Count offset from the start of the file
}
31 \twocolitem{{\bf wxFromCurrent
}}{Count offset from the current position of the file pointer
}
32 \twocolitem{{\bf wxFromEnd
}}{Count offset from the end of the file (backwards)
}
35 \latexignore{\rtfignore{\wxheading{Members
}}}
38 \membersection{wxFFile::wxFFile
}\label{wxffilector
}
40 \func{}{wxFFile
}{\void}
44 \func{}{wxFFile
}{\param{const char*
}{ filename
},
\param{const char*
}{ mode = "r"
}}
46 Opens a file with the given mode. As there is no way to return whether the
47 operation was successful or not from the constructor you should test the
48 return value of
\helpref{IsOpened
}{wxffileisopened
} to check that it didn't
51 \func{}{wxFFile
}{\param{FILE*
}{ fp
}}
53 Opens a file with the given file pointer, which has already been opened.
55 \wxheading{Parameters
}
57 \docparam{filename
}{The filename.
}
59 \docparam{mode
}{The mode in which to open the file using standard C strings.
60 Note that you should use
{\tt "b"
} flag if you use binary files under Windows
61 or the results might be unexpected due to automatic newline conversion done
64 \docparam{fp
}{An existing file descriptor, such as stderr.
}
67 \membersection{wxFFile::
\destruct{wxFFile
}}\label{wxffiledtor
}
69 \func{}{\destruct{wxFFile
}}{\void}
71 Destructor will close the file.
73 NB: it is not virtual so you should
{\it not
} derive from wxFFile!
76 \membersection{wxFFile::Attach
}\label{wxffileattach
}
78 \func{void
}{Attach
}{\param{FILE*
}{ fp
}}
80 Attaches an existing file pointer to the wxFFile object.
82 The descriptor should be already opened and it will be closed by wxFFile
86 \membersection{wxFFile::Close
}\label{wxffileclose
}
88 \func{bool
}{Close
}{\void}
90 Closes the file and returns
\true on success.
93 \membersection{wxFFile::Detach
}\label{wxffiledetach
}
95 \func{void
}{Detach
}{\void}
97 Get back a file pointer from wxFFile object -- the caller is responsible for closing the file if this
98 descriptor is opened.
\helpref{IsOpened()
}{wxffileisopened
} will return
\false after call to Detach().
101 \membersection{wxFFile::fp
}\label{wxffilefp
}
103 \constfunc{FILE *
}{fp
}{\void}
105 Returns the file pointer associated with the file.
108 \membersection{wxFFile::Eof
}\label{wxffileeof
}
110 \constfunc{bool
}{Eof
}{\void}
112 Returns
\true if the an attempt has been made to read
{\it past
}
115 Note that the behaviour of the file descriptor based class
116 \helpref{wxFile
}{wxfile
} is different as
\helpref{wxFile::Eof
}{wxfileeof
}
117 will return
\true here as soon as the last byte of the file has been
120 Also note that this method may only be called for opened files and may crash if
121 the file is not opened.
125 \helpref{IsOpened
}{wxffileisopened
}
128 \membersection{wxFFile::Error
}\label{wxffileerror
}
130 Returns
\true if an error has occured on this file, similar to the standard
131 \texttt{ferror()
} function.
133 Please note that this method may only be called for opened files and may crash
134 if the file is not opened.
138 \helpref{IsOpened
}{wxffileisopened
}
141 \membersection{wxFFile::Flush
}\label{wxffileflush
}
143 \func{bool
}{Flush
}{\void}
145 Flushes the file and returns
\true on success.
148 \membersection{wxFFile::IsOpened
}\label{wxffileisopened
}
150 \constfunc{bool
}{IsOpened
}{\void}
152 Returns
\true if the file is opened. Most of the methods of this class may only
153 be used for an opened file.
156 \membersection{wxFFile::Length
}\label{wxffilelength
}
158 \constfunc{wxFileOffset
}{Length
}{\void}
160 Returns the length of the file.
163 \membersection{wxFFile::Open
}\label{wxffileopen
}
165 \func{bool
}{Open
}{\param{const char*
}{ filename
},
\param{const char*
}{ mode = "r"
}}
167 Opens the file, returning
\true if successful.
169 \wxheading{Parameters
}
171 \docparam{filename
}{The filename.
}
173 \docparam{mode
}{The mode in which to open the file.
}
176 \membersection{wxFFile::Read
}\label{wxffileread
}
178 \func{size
\_t}{Read
}{\param{void*
}{ buffer
},
\param{size
\_t}{ count
}}
180 Reads the specified number of bytes into a buffer, returning the actual number read.
182 \wxheading{Parameters
}
184 \docparam{buffer
}{A buffer to receive the data.
}
186 \docparam{count
}{The number of bytes to read.
}
188 \wxheading{Return value
}
190 The number of bytes read.
193 \membersection{wxFFile::Seek
}\label{wxffileseek
}
195 \func{bool
}{Seek
}{\param{wxFileOffset
}{ofs
},
\param{wxSeekMode
}{mode = wxFromStart
}}
197 Seeks to the specified position and returns
\true on success.
199 \wxheading{Parameters
}
201 \docparam{ofs
}{Offset to seek to.
}
203 \docparam{mode
}{One of
{\bf wxFromStart
},
{\bf wxFromEnd
},
{\bf wxFromCurrent
}.
}
206 \membersection{wxFFile::SeekEnd
}\label{wxffileseekend
}
208 \func{bool
}{SeekEnd
}{\param{wxFileOffset
}{ofs =
0}}
210 Moves the file pointer to the specified number of bytes before the end of the file
211 and returns
\true on success.
213 \wxheading{Parameters
}
215 \docparam{ofs
}{Number of bytes before the end of the file.
}
218 \membersection{wxFFile::Tell
}\label{wxffiletell
}
220 \constfunc{wxFileOffset
}{Tell
}{\void}
222 Returns the current position.
225 \membersection{wxFFile::Write
}\label{wxffilewrite
}
227 \func{size
\_t}{Write
}{\param{const void*
}{ buffer
},
\param{size
\_t}{ count
}}
229 Writes the specified number of bytes from a buffer.
231 \wxheading{Parameters
}
233 \docparam{buffer
}{A buffer containing the data.
}
235 \docparam{count
}{The number of bytes to write.
}
237 \wxheading{Return value
}
239 Number of bytes written.
242 \membersection{wxFFile::Write
}\label{wxffilewrites
}
244 \func{bool
}{Write
}{\param{const wxString\&
}{s
},
\param{wxMBConv\&
}{ conv = wxConvUTF8
}}
246 Writes the contents of the string to the file, returns
\true on success.
248 The second argument is only meaningful in Unicode build of wxWidgets when
249 {\it conv
} is used to convert
{\it s
} to multibyte representation.