/////////////////////////////////////////////////////////////////////////////
// Name: file.h
-// Purpose: documentation for wxTempFile class
+// Purpose: interface of wxTempFile
// Author: wxWidgets team
// RCS-ID: $Id$
// Licence: wxWindows license
/**
@class wxTempFile
@wxheader{file.h}
-
+
wxTempFile provides a relatively safe way to replace the contents of the
existing file. The name is explained by the fact that it may be also used as
just a temporary file if you don't replace the old file contents.
-
+
Usually, when a program replaces the contents of some file it first opens it for
writing, thus losing all of the old data and then starts recreating it. This
approach is not very safe because during the regeneration of the file bad things
generation takes long time) and, finally, any other external interrupts (power
supply failure or a disk error) will leave you without either the original file
or the new one.
-
+
wxTempFile addresses this problem by creating a temporary file which is meant to
replace the original file - but only after it is fully written. So, if the user
interrupts the program during the file generation, the old file won't be lost.
Also, if the program discovers itself that it doesn't want to replace the old
file there is no problem - in fact, wxTempFile will @b not replace the old
- file by default, you should explicitly call wxTempFile::Commit
+ file by default, you should explicitly call wxTempFile::Commit
to do it. Calling wxTempFile::Discard explicitly discards any
modifications: it closes and deletes the temporary file and leaves the original
file unchanged. If you don't call neither of Commit() and Discard(), the
destructor will call Discard() automatically.
-
+
To summarize: if you want to replace another file, create an instance of
wxTempFile passing the name of the file to be replaced to the constructor (you
- may also use default constructor and pass the file name to
- wxTempFile::Open). Then you can wxTempFile::write
+ may also use default constructor and pass the file name to
+ wxTempFile::Open). Then you can wxTempFile::write
to wxTempFile using wxFile-like functions and later call
Commit() to replace the old file (and close this one) or call Discard() to
cancel
the modifications.
-
+
@library{wxbase}
@category{file}
*/
-class wxTempFile
+class wxTempFile
{
public:
/**
- Associates wxTempFile with the file to be replaced and opens it. You should use
+ Associates wxTempFile with the file to be replaced and opens it. You should use
IsOpened() to verify if the constructor succeeded.
*/
wxTempFile(const wxString& strName);
/**
Returns @true if the file was successfully opened.
*/
- bool IsOpened();
+ bool IsOpened() const;
/**
Returns the length of the file.
*/
- wxFileOffset Length();
+ wxFileOffset Length() const;
/**
Open the temporary file, returns @true on success, @false if an error
occurred.
-
- @e strName is the name of file to be replaced. The temporary file is always
- created in the directory where @e strName is. In particular, if
- @e strName doesn't include the path, it is created in the current directory
+ @a strName is the name of file to be replaced. The temporary file is always
+ created in the directory where @a strName is. In particular, if
+ @a strName doesn't include the path, it is created in the current directory
and the program should have write access to it for the function to succeed.
*/
bool Open(const wxString& strName);
another
error occurred.
*/
- wxFileOffset Tell();
+ wxFileOffset Tell() const;
/**
Write to the file, return @true on success, @false on failure.
-
The second argument is only meaningful in Unicode build of wxWidgets when
- @e conv is used to convert @e str to multibyte representation.
+ @a conv is used to convert @a str to multibyte representation.
*/
bool Write(const wxString& str,
const wxMBConv& conv = wxConvUTF8);
};
+
/**
@class wxFile
@wxheader{file.h}
-
+
A wxFile performs raw 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. wxFile also automatically closes the file in
its destructor making it unnecessary to worry about forgetting to do it.
- wxFile is a wrapper around @c file descriptor. - see also
+ wxFile is a wrapper around @c file descriptor. - see also
wxFFile for a wrapper around @c FILE structure.
-
- @c wxFileOffset is used by the wxFile functions which require offsets as
+
+ @c wxFileOffset is used by the wxFile functions which require offsets as
parameter or return them. If the platform supports it, wxFileOffset is a typedef
for a native 64 bit integer, otherwise a 32 bit integer is used for
wxFileOffset.
-
+
@library{wxbase}
@category{file}
*/
-class wxFile
+class wxFile
{
public:
//@{
/**
Associates the file with the given file descriptor, which has already been
opened.
-
- @param filename
- The filename.
-
- @param mode
- The mode in which to open the file. May be one of read(), write() and
+
+ @param filename
+ The filename.
+ @param mode
+ The mode in which to open the file. May be one of read(), write() and
wxFile::read_write.
-
- @param fd
- An existing file descriptor (see Attach() for the list of predefined
+ @param fd
+ An existing file descriptor (see Attach() for the list of predefined
descriptors)
*/
wxFile();
- wxFile(const wxString& filename,
- wxFile::OpenMode mode = wxFile::read);
- wxFile(int fd);
+ wxFile(const wxString& filename,
+ wxFile::OpenMode mode = wxFile::read);
+ wxFile(int fd);
//@}
/**
Destructor will close the file.
-
- @b NB: it is not virtual so you should not use wxFile polymorphically.
+ @note it is not virtual so you should not use wxFile polymorphically.
*/
~wxFile();
(and
have symbolic names of @b wxFile::fd_stdin, @b wxFile::fd_stdout and @b
wxFile::fd_stderr).
-
The descriptor should be already opened and it will be closed by wxFile
object.
*/
@true
will ensure it is overwritten.
*/
- bool Create(const wxString& filename, bool overwrite = @false,
+ bool Create(const wxString& filename, bool overwrite = false,
int access = wxS_DEFAULT);
/**
/**
Returns @true if the end of the file has been reached.
-
- Note that the behaviour of the file pointer based class
- wxFFile is different as wxFFile::Eof
- will return @true here only if an attempt has been made to read
+ Note that the behaviour of the file pointer based class
+ wxFFile is different as wxFFile::Eof
+ will return @true here only if an attempt has been made to read
@e 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
+ file into memory, you should write a loop which uses
Read() repeatedly and tests its return condition instead
of using Eof() as this will not work for special files under Unix.
*/
-#define bool Eof() /* implementation is private */
+ bool Eof() const;
/**
Returns @true if the given name specifies an existing regular file (not a
/**
Flushes the file descriptor.
-
Note that Flush() is not implemented on some Windows compilers
due to a missing fsync function, which reduces the usefulness of this function
(it can still be called but it will do nothing on unsupported compilers).
/**
Returns the type of the file. Possible return values are:
*/
- wxFileKind GetKind();
+ wxFileKind GetKind() const;
/**
Returns @true if the file has been opened.
*/
- bool IsOpened();
+ bool IsOpened() const;
/**
Returns the length of the file.
*/
- wxFileOffset Length();
+ wxFileOffset Length() const;
/**
Opens the file, returning @true if successful.
-
- @param filename
- The filename.
-
- @param mode
- The mode in which to open the file. May be one of read(), write() and
+
+ @param filename
+ The filename.
+ @param mode
+ The mode in which to open the file. May be one of read(), write() and
wxFile::read_write.
*/
bool Open(const wxString& filename,
if there was an error.
*/
size_t Read(void* buffer, size_t count);
- Parameters Return value
-The number of bytes read, or the symbol wxInvalidOffset();
+ Parameters Return value
+ The number of bytes read, or the symbol wxInvalidOffset();
//@}
/**
Seeks to the specified position.
-
- @param ofs
- Offset to seek to.
-
- @param mode
- One of wxFromStart, wxFromEnd, wxFromCurrent.
-
- @returns The actual offset position achieved, or wxInvalidOffset on
- failure.
+
+ @param ofs
+ Offset to seek to.
+ @param mode
+ One of wxFromStart, wxFromEnd, wxFromCurrent.
+
+ @return The actual offset position achieved, or wxInvalidOffset on
+ failure.
*/
wxFileOffset Seek(wxFileOffset ofs,
wxSeekMode mode = wxFromStart);
Moves the file pointer to the specified number of bytes relative to the end of
the file. For example, @c SeekEnd(-5) would position the pointer 5
bytes before the end.
-
- @param ofs
- Number of bytes before the end of the file.
-
- @returns The actual offset position achieved, or wxInvalidOffset on
- failure.
+
+ @param ofs
+ Number of bytes before the end of the file.
+
+ @return The actual offset position achieved, or wxInvalidOffset on
+ failure.
*/
wxFileOffset SeekEnd(wxFileOffset ofs = 0);
another
error occurred.
*/
- wxFileOffset Tell();
+ wxFileOffset Tell() const;
/**
Writes the contents of the string to the file, returns @true on success.
-
The second argument is only meaningful in Unicode build of wxWidgets when
- @e conv is used to convert @e s to multibyte representation.
-
+ @a conv is used to convert @a s to multibyte representation.
Note that this method only works with @c NUL-terminated strings, if you want
- to write data with embedded @c NULs to the file you should use the other
+ to write data with embedded @c NULs to the file you should use the other
@ref write() "Write() overload".
*/
bool Write(const wxString& s, const wxMBConv& conv = wxConvUTF8);
/**
Returns the file descriptor associated with the file.
*/
-#define int fd() /* implementation is private */
+ int fd() const;
};
+
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