all, but using it brings you automatic error checking and hides differences
between platforms and compilers. wxFile also automatically closes the file in
its destructor making it unnecessary to worry about forgetting to do it.
+wxFile is a wrapper around {\tt file descriptor.} - see also
+\helpref{wxFFile}{wxffile} for a wrapper around {\tt FILE} structure.
\wxheading{Derived from}
wx/file.h defines the following constants:
-{\small
\begin{verbatim}
#define wxS_IRUSR 00400
#define wxS_IWUSR 00200
// default mode for the new files: corresponds to umask 022
#define wxS_DEFAULT (wxS_IRUSR | wxS_IWUSR | wxS_IRGRP | wxS_IWGRP | wxS_IROTH | wxS_IWOTH)
\end{verbatim}
-}
These constants define the file access rights and are used with
\helpref{wxFile::Create}{wxfilecreate} and \helpref{wxFile::Open}{wxfileopen}.
The {\it OpenMode} enumeration defines the different modes for opening a file,
-it's defined inside wxFile class so its members should be specified with {\it wxFile::} scope
+it is defined inside wxFile class so its members should be specified with {\it wxFile::} scope
resolution prefix. It is also used with \helpref{wxFile::Access}{wxfileaccess} function.
\twocolwidtha{7cm}
\twocolitem{{\bf wxFile::read\_write}}{Open file for reading and writing; can not be used with Access()}
\twocolitem{{\bf wxFile::write\_append}}{Open file for appending: the file is opened for writing, but the old
contents of the file is not erased and the file pointer is initially placed at the end of the file;
-can not be used with Access()}
+can not be used with Access(). This is the same as {\bf wxFile::write} if the
+file doesn't exist.}
+\twocolitem{{\bf wxFile::write\_excl}}{Open the file securely for writing (Uses O\_EXCL | O\_CREAT).
+Will fail if the file already exists, else create and open it atomically. Useful for opening temporary files without being vulnerable to race exploits.}
\end{twocollist}
Other constants defined elsewhere but used by wxFile functions are wxInvalidOffset which represents an
Attaches an existing file descriptor to the wxFile object. Example of predefined
file descriptors are 0, 1 and 2 which correspond to stdin, stdout and stderr (and
-have symbolic names of wxFile::fd\_stdin, wxFile::fd\_stdout and wxFile::fd\_stderr).
+have symbolic names of {\bf wxFile::fd\_stdin}, {\bf wxFile::fd\_stdout} and {\bf wxFile::fd\_stderr}).
The descriptor should be already opened and it will be closed by wxFile
object.
\constfunc{bool}{Eof}{\void}
-Returns TRUE if the end of the file has been reached (the last byte has been read).
+Returns TRUE if the end of the file has been reached.
-Note that the behaviour of the file pointer based class
-\helpref{wxFFile}{wxffile} is different as \helpref{wxFFile::Eof}{wxffileeof}
-will return TRUE here only if an attempt has been made to read
-{\it past} the last byte of the file.
+Note that the behaviour of the file pointer based class
+\helpref{wxFFile}{wxffile} is different as \helpref{wxFFile::Eof}{wxffileeof}
+will return TRUE here only if an attempt has been made to read
+{\it past} the last byte of the file, while wxFile::Eof() will return TRUE
+even before such attempt is made if the file pointer is at the last position
+in the file.
+
+Note also that this function doesn't work on unseekable file descriptors
+(examples include pipes, terminals and sockets under Unix) and an attempt to
+use it will result in an error message in such case. So, to read the entire
+file into memory, you should write a loop which uses
+\helpref{Read}{wxfileread} repeatedly and tests its return condition instead
+of using Eof() as this will not work for special files under Unix.
\membersection{wxFile::Exists}\label{wxfileexists}
\constfunc{off\_t}{Tell}{\void}
Returns the current position or wxInvalidOffset if file is not opened or if another
-error occured.
+error occurred.
\membersection{wxFile::Write}\label{wxfilewrite}
-\func{bool}{Write}{\param{const void*}{ buffer}, \param{off\_t}{ count}}
+\func{size\_t}{Write}{\param{const void*}{ buffer}, \param{off\_t}{ count}}
Writes the specified number of bytes from a buffer.
\wxheading{Return value}
-TRUE if the operation was successful.
+the number of bytes actually written
\membersection{wxFile::Write}\label{wxfilewrites}
-\func{bool}{Write}{\param{const wxString\& }{s}}
+\func{bool}{Write}{\param{const wxString\& }{s}, \param{wxMBConv&}{ conv = wxConvLibc}}
Writes the contents of the string to the file, returns TRUE on success.
+The second argument is only meaningful in Unicode build of wxWindows when
+{\it conv} is used to convert {\it s} to multibyte representation.
+
\section{\class{wxFFile}}\label{wxffile}
-A wxFFile performs raw file I/O. This is a very small class designed to
+wxFFile implements buffered file I/O. This is a very small class designed to
minimize the overhead of using it - in fact, there is hardly any overhead at
all, but using it brings you automatic error checking and hides differences
-between platforms and compilers.
+between platforms and compilers. It wraps inside it a {\tt FILE *} handle used
+by standard C IO library (also known as {\tt stdio}).
\wxheading{Derived from}
\docparam{filename}{The filename.}
-\docparam{mode}{The mode in which to open the file using standard C strings.}
+\docparam{mode}{The mode in which to open the file using standard C strings.
+Note that you should use {\tt "b"} flag if you use binary files under Windows
+or the results might be unexpected due to automatic newline conversion done
+for the text files.}
\docparam{fp}{An existing file descriptor, such as stderr.}
\membersection{wxFFile::Write}\label{wxffilewrite}
-\func{size_t}{Write}{\param{const void*}{ buffer}, \param{size\_t}{ count}}
+\func{size\_t}{Write}{\param{const void*}{ buffer}, \param{size\_t}{ count}}
Writes the specified number of bytes from a buffer.
\membersection{wxFFile::Write}\label{wxffilewrites}
-\func{bool}{Write}{\param{const wxString\& }{s}}
+\func{bool}{Write}{\param{const wxString\& }{s}, \param{wxMBConv&}{ conv = wxConvLibc}}
Writes the contents of the string to the file, returns TRUE on success.
+The second argument is only meaningful in Unicode build of wxWindows when
+{\it conv} is used to convert {\it s} to multibyte representation.
+
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