Inheritance diagram for __gnu_cxx::stdio_filebuf:

[legend]

Public Types

typedef codecvt< char_type,
char, __state_type > __codecvt_type
typedef __basic_file< char > __file_type
typedef basic_filebuf
< char_type, traits_type > __filebuf_type
typedef traits_type::state_type __state_type
typedef basic_streambuf
< char_type, traits_type > __streambuf_type
typedef _CharT char_type
typedef traits_type::int_type int_type
typedef traits_type::off_type off_type
typedef traits_type::pos_type pos_type
typedef std::size_t size_t
typedef _Traits traits_type

Public Member Functions

stdio_filebuf ()
stdio_filebuf (int __fd, std::ios_base::openmode __mode, size_t __size=static_cast< size_t >(BUFSIZ))
stdio_filebuf (std::__c_file *__f, std::ios_base::openmode __mode, size_t __size=static_cast< size_t >(BUFSIZ))
virtual ~stdio_filebuf ()
__filebuf_type * close ()
int fd ()
std::__c_file * file ()
bool is_open () const throw ()
__filebuf_type * open (const char *__s, ios_base::openmode __mode)
__filebuf_type * open (const std::string &__s, ios_base::openmode __mode)

Protected Member Functions

void _M_allocate_internal_buffer ()
bool _M_convert_to_external (char_type *, streamsize)
void _M_create_pback ()
void _M_destroy_internal_buffer () throw ()
void _M_destroy_pback () throw ()
int _M_get_ext_pos (__state_type &__state)
pos_type _M_seek (off_type __off, ios_base::seekdir __way, __state_type __state)
void _M_set_buffer (streamsize __off)
bool _M_terminate_output ()
virtual void imbue (const locale &__loc)
virtual int_type overflow (int_type __c=_Traits::eof())
virtual int_type pbackfail (int_type __c=_Traits::eof())
virtual pos_type seekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode __mode=ios_base::in|ios_base::out)
virtual pos_type seekpos (pos_type __pos, ios_base::openmode __mode=ios_base::in|ios_base::out)
virtual __streambuf_type * setbuf (char_type *__s, streamsize __n)
virtual streamsize showmanyc ()
virtual int sync ()
virtual int_type underflow ()
virtual streamsize xsgetn (char_type *__s, streamsize __n)
virtual streamsize xsputn (const char_type *__s, streamsize __n)

Protected Attributes

char_type * _M_buf
bool _M_buf_allocated
size_t _M_buf_size
const __codecvt_type * _M_codecvt
char * _M_ext_buf
streamsize _M_ext_buf_size
char * _M_ext_end
const char * _M_ext_next
__file_type _M_file
__c_lock _M_lock
ios_base::openmode _M_mode
bool _M_reading
__state_type _M_state_beg
__state_type _M_state_cur
__state_type _M_state_last
bool _M_writing

char_type _M_pback
char_type * _M_pback_cur_save
char_type * _M_pback_end_save
bool _M_pback_init

Friends

class ios_base

Detailed Description

Provides a layer of compatibility for C/POSIX.

This GNU extension provides extensions for working with standard C FILE*'s and POSIX file descriptors. It must be instantiated by the user with the type of character used in the file stream, e.g., stdio_filebuf<char>.

Constructor & Destructor Documentation

__gnu_cxx::stdio_filebuf::stdio_filebuf ( ) [inline]

deferred initialization

Definition at line 66 of file stdio_filebuf.h.

__gnu_cxx::stdio_filebuf::stdio_filebuf	(	int	__fd,
		std::ios_base::openmode	__mode,
		size_t	__size = `static_cast<size_t>(BUFSIZ)`
	)

Parameters:

fd	An open file descriptor.
mode	Same meaning as in a standard filebuf.
size	Optimal or preferred size of internal buffer, in chars.

This constructor associates a file stream buffer with an open POSIX file descriptor. The file descriptor will be automatically closed when the stdio_filebuf is closed/destroyed.

Definition at line 128 of file stdio_filebuf.h.

__gnu_cxx::stdio_filebuf::stdio_filebuf	(	std::__c_file *	__f,
		std::ios_base::openmode	__mode,
		size_t	__size = `static_cast<size_t>(BUFSIZ)`
	)

Parameters:

f	An open `FILE*`.
mode	Same meaning as in a standard filebuf.
size	Optimal or preferred size of internal buffer, in chars. Defaults to system's `BUFSIZ`.

This constructor associates a file stream buffer with an open C FILE*. The FILE* will not be automatically closed when the stdio_filebuf is closed/destroyed.

Definition at line 144 of file stdio_filebuf.h.

__gnu_cxx::stdio_filebuf::~stdio_filebuf ( ) [virtual]

Closes the external data stream if the file descriptor constructor was used.

Definition at line 123 of file stdio_filebuf.h.

Member Function Documentation

void std::basic_filebuf::_M_create_pback ( ) [inline, protected, inherited]

Initializes pback buffers, and moves normal buffers to safety. Assumptions: _M_in_cur has already been moved back

Definition at line 174 of file fstream.

void std::basic_filebuf::_M_destroy_pback ( ) throw () [inline, protected, inherited]

Deactivates pback buffer contents, and restores normal buffer. Assumptions: The pback buffer has only moved forward.

Definition at line 191 of file fstream.

void std::basic_filebuf::_M_set_buffer ( streamsize __off ) [inline, protected, inherited]

This function sets the pointers of the internal buffer, both get and put areas. Typically:

__off == egptr() - eback() upon underflow/uflow (read mode); __off == 0 upon overflow (write mode); __off == -1 upon open, setbuf, seekoff/pos (uncommitted mode).

NB: epptr() - pbase() == _M_buf_size - 1, since _M_buf_size reflects the actual allocated memory and the last cell is reserved for the overflow char of a full put area.

Definition at line 392 of file fstream.

__filebuf_type* std::basic_filebuf::close ( ) [inherited]

Closes the currently associated file.

Returns:: this on success, NULL on failure

If no file is currently open, this function immediately fails.

If a put buffer area exists, overflow(eof) is called to flush all the characters. The file is then closed.

If any operations fail, this function also fails.

int __gnu_cxx::stdio_filebuf::fd ( ) [inline]

Returns:: The underlying file descriptor.

Once associated with an external data stream, this function can be used to access the underlying POSIX file descriptor. Note that there is no way for the library to track what you do with the descriptor, so be careful.

Definition at line 109 of file stdio_filebuf.h.

std::__c_file* __gnu_cxx::stdio_filebuf::file ( ) [inline]

Returns:: The underlying FILE*.

This function can be used to access the underlying "C" file pointer. Note that there is no way for the library to track what you do with the file, so be careful.

Definition at line 119 of file stdio_filebuf.h.

bool std::basic_filebuf::is_open ( ) const throw () [inline, inherited]

Returns true if the external file is open.

Definition at line 224 of file fstream.

__filebuf_type* std::basic_filebuf::open	(	const char *	__s,
		ios_base::openmode	__mode
	)		`[inherited]`

Opens an external file.

Parameters:

s	The name of the file.
mode	The open mode flags.

Returns:: this on success, NULL on failure

If a file is already open, this function immediately fails. Otherwise it tries to open the file named s using the flags given in mode.

Table 92, adapted here, gives the relation between openmode combinations and the equivalent fopen() flags. (NB: lines app, in|out|app, in|app, binary|app, binary|in|out|app, and binary|in|app per DR 596) +---------------------------------------------------------+ | ios_base Flag combination stdio equivalent | |binary in out trunc app | +---------------------------------------------------------+ | + w | | + + a | | + a | | + + w | | + r | | + + r+ | | + + + w+ | | + + + a+ | | + + a+ | +---------------------------------------------------------+ | + + wb | | + + + ab | | + + ab | | + + + wb | | + + rb | | + + + r+b | | + + + + w+b | | + + + + a+b | | + + + a+b | +---------------------------------------------------------+

__filebuf_type* std::basic_filebuf::open	(	const std::string &	__s,
		ios_base::openmode	__mode
	)		`[inline, inherited]`

Opens an external file.

Parameters:

s	The name of the file.
mode	The open mode flags.

Returns:: this on success, NULL on failure

Definition at line 277 of file fstream.

virtual __streambuf_type* std::basic_filebuf::setbuf	(	char_type *	__s,
		streamsize	__n
	)		`[protected, virtual, inherited]`

Manipulates the buffer.

Parameters:

s	Pointer to a buffer area.
n	Size of s.

Returns:: this

If no file has been opened, and both s and n are zero, then the stream becomes unbuffered. Otherwise, s is used as a buffer; see http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html for more.

Member Data Documentation

char_type* std::basic_filebuf::_M_buf [protected, inherited]

Pointer to the beginning of internal buffer.

Definition at line 111 of file fstream.

size_t std::basic_filebuf::_M_buf_size [protected, inherited]

Actual size of internal buffer. This number is equal to the size of the put area + 1 position, reserved for the overflow char of a full area.

Definition at line 118 of file fstream.

char* std::basic_filebuf::_M_ext_buf [protected, inherited]

Buffer for external characters. Used for input when codecvt::always_noconv() == false. When valid, this corresponds to eback().

Definition at line 153 of file fstream.

streamsize std::basic_filebuf::_M_ext_buf_size [protected, inherited]

Size of buffer held by _M_ext_buf.

Definition at line 158 of file fstream.

const char* std::basic_filebuf::_M_ext_next [protected, inherited]

Pointers into the buffer held by _M_ext_buf that delimit a subsequence of bytes that have been read but not yet converted. When valid, _M_ext_next corresponds to egptr().

Definition at line 165 of file fstream.

ios_base::openmode std::basic_filebuf::_M_mode [protected, inherited]

Place to stash in || out || in | out settings for current filebuf.

Definition at line 96 of file fstream.

char_type std::basic_filebuf::_M_pback [protected, inherited]

Necessary bits for putback buffer management.