fix for wxExecute(subprocess which produces a lot of output) bug

[wxWidgets.git] / docs / latex / wx / file.tex

diff --git a/docs/latex/wx/file.tex b/docs/latex/wx/file.tex
index 79260df675c112fdab7ee52e7d92cf5faa7e9c1e..943240de4b2d05035e4f4dff170d31cbd54a5e81 100644 (file)
--- a/docs/latex/wx/file.tex
+++ b/docs/latex/wx/file.tex
@@ -5,6 +5,8 @@ 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. wxFile also automatically closes the file in
 its destructor making it unnecessary to worry about forgetting to do it.
 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}
 
 
 \wxheading{Derived from}
 


@@ -18,7 +20,6 @@ None.
 
 wx/file.h defines the following constants:
 
 
 wx/file.h defines the following constants:
 

-{\small

 \begin{verbatim}
 #define wxS_IRUSR 00400
 #define wxS_IWUSR 00200
 \begin{verbatim}
 #define wxS_IRUSR 00400
 #define wxS_IWUSR 00200


@@ -35,13 +36,12 @@ wx/file.h defines the following constants:
 // 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}
 // 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,
 
 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}
 resolution prefix. It is also used with \helpref{wxFile::Access}{wxfileaccess} function.
 
 \twocolwidtha{7cm}


@@ -52,7 +52,8 @@ or test if it can be opened for writing with Access()}
 \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;
 \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.}

 \end{twocollist}
 
 Other constants defined elsewhere but used by wxFile functions are wxInvalidOffset which represents an
 \end{twocollist}
 
 Other constants defined elsewhere but used by wxFile functions are wxInvalidOffset which represents an


@@ -114,7 +115,7 @@ values of wxFile::read or wxFile::write really make sense here.
 
 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
 
 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.
 
 The descriptor should be already opened and it will be closed by wxFile
 object.


@@ -149,12 +150,21 @@ Returns the file descriptor associated with the file.
 
 \constfunc{bool}{Eof}{\void}
 
 
 \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}
 
 
 \membersection{wxFile::Exists}\label{wxfileexists}
 


@@ -248,11 +258,11 @@ The actual offset position achieved, or wxInvalidOffset on failure.
 \constfunc{off\_t}{Tell}{\void}
 
 Returns the current position or wxInvalidOffset if file is not opened or if another
 \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}
 
 
 \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.
 
 
 Writes the specified number of bytes from a buffer.
 


@@ -264,20 +274,24 @@ Writes the specified number of bytes from a buffer.
 
 \wxheading{Return value}
 
 
 \wxheading{Return value}
 

-TRUE if the operation was successful.
+the number of bytes actually written

 
 \membersection{wxFile::Write}\label{wxfilewrites}
 
 
 \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.
 
 
 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}
 
 \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
 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}
 
 
 \wxheading{Derived from}
 


@@ -317,7 +331,10 @@ Opens a file with the given file pointer, which has already been opened.
 
 \docparam{filename}{The filename.}
 
 
 \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.}
 
 
 \docparam{fp}{An existing file descriptor, such as stderr.}
 


@@ -446,7 +463,7 @@ Returns the current position.
 
 \membersection{wxFFile::Write}\label{wxffilewrite}
 
 
 \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.
 
 
 Writes the specified number of bytes from a buffer.
 


@@ -462,7 +479,10 @@ Number of bytes written.
 
 \membersection{wxFFile::Write}\label{wxffilewrites}
 
 
 \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.
 
 
 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.
+