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__gnu_cxx::stdio_filebuf

__gnu_cxx::stdio_filebuf

Section: C Library Functions (3) Updated: 27 Aug 2009
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NAME

__gnu_cxx::stdio_filebuf -

Provides a layer of compatibility for C/POSIX.

 

SYNOPSIS


Inherits std::basic_filebuf< _CharT, _Traits >.  

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


__filebuf_type * close () throw ()

int fd ()

std::__c_file * file ()

streamsize in_avail ()

bool is_open () const throw ()

__filebuf_type * open (const char *__s, ios_base::openmode __mode)

int_type sbumpc ()

int_type sgetc ()

streamsize sgetn (char_type *__s, streamsize __n)

int_type snextc ()

int_type sputbackc (char_type __c)

int_type sputc (char_type __c)

streamsize sputn (const char_type *__s, streamsize __n)

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

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

stdio_filebuf ()

void stossc ()

int_type sungetc ()

virtual ~stdio_filebuf ()
 

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 ()

pos_type _M_seek (off_type __off, ios_base::seekdir __way, __state_type __state)

void _M_set_buffer (streamsize __off)

bool _M_terminate_output ()

void gbump (int __n)

virtual void imbue (const locale &__loc)

virtual int_type overflow (int_type __c=_Traits::eof())

virtual int_type pbackfail (int_type __c=_Traits::eof())

void pbump (int __n)

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)

void setg (char_type *__gbeg, char_type *__gnext, char_type *__gend)

void setp (char_type *__pbeg, char_type *__pend)

virtual streamsize showmanyc ()

virtual int sync ()

virtual int_type uflow ()

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


streamsize __copy_streambufs (__streambuf_type *__sbin, __streambuf_type *__sbout)

class basic_ios< char_type, traits_type >

class basic_istream< char_type, traits_type >

class basic_ostream< char_type, traits_type >

template<typename _CharT2 , typename _Traits2 , typename _Alloc > basic_istream< _CharT2, _Traits2 > & getline (basic_istream< _CharT2, _Traits2 > &, basic_string< _CharT2, _Traits2, _Alloc > &, _CharT2)

class ios_base

class istreambuf_iterator< char_type, traits_type >

template<typename _CharT2 , typename _Traits2 , typename _Alloc > basic_istream< _CharT2, _Traits2 > & operator>> (basic_istream< _CharT2, _Traits2 > &, basic_string< _CharT2, _Traits2, _Alloc > &)

template<typename _CharT2 , typename _Traits2 > basic_istream< _CharT2, _Traits2 > & operator>> (basic_istream< _CharT2, _Traits2 > &, _CharT2 *)

class ostreambuf_iterator< char_type, traits_type >

locale getloc () const

locale pubimbue (const locale &__loc)

pos_type pubseekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode __mode=ios_base::in|ios_base::out)

pos_type pubseekpos (pos_type __sp, ios_base::openmode __mode=ios_base::in|ios_base::out)

__streambuf_type * pubsetbuf (char_type *__s, streamsize __n)

int pubsync ()

locale _M_buf_locale

char_type * _M_in_beg

char_type * _M_in_cur

char_type * _M_in_end

char_type * _M_out_beg

char_type * _M_out_cur

char_type * _M_out_end

char_type * eback () const

char_type * egptr () const

char_type * epptr () const

char_type * gptr () const

char_type * pbase () const

char_type * pptr () const
 

Detailed Description

 

template<typename _CharT, typename _Traits = std::char_traits<_CharT>> class __gnu_cxx::stdio_filebuf< _CharT, _Traits >

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>.

Definition at line 52 of file stdio_filebuf.h.  

Member Typedef Documentation

 

typedef basic_streambuf<char_type, traits_type> __streambuf_type [inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 78 of file fstream.  

typedef _CharT char_typeThese are standard types. They permit a standardized way of referring to names of (or names dependant on) the template parameters, which are specific to the implementation.

Reimplemented from basic_filebuf< _CharT, _Traits >.

Definition at line 56 of file stdio_filebuf.h.  

typedef traits_type::int_type int_type

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Reimplemented from basic_filebuf< _CharT, _Traits >.

Definition at line 58 of file stdio_filebuf.h.  

typedef traits_type::off_type off_type

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Reimplemented from basic_filebuf< _CharT, _Traits >.

Definition at line 60 of file stdio_filebuf.h.  

typedef traits_type::pos_type pos_type

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Reimplemented from basic_filebuf< _CharT, _Traits >.

Definition at line 59 of file stdio_filebuf.h.  

typedef _Traits traits_type

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Reimplemented from basic_filebuf< _CharT, _Traits >.

Definition at line 57 of file stdio_filebuf.h.  

Constructor & Destructor Documentation

 

stdio_filebuf () [inline]deferred initialization

Definition at line 67 of file stdio_filebuf.h.  

stdio_filebuf (int __fd, std::ios_base::openmode __mode, size_t __size = static_cast<size_t>(BUFSIZ)) [inline]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 129 of file stdio_filebuf.h.

References basic_filebuf< _CharT, _Traits >::is_open().  

stdio_filebuf (std::__c_file * __f, std::ios_base::openmode __mode, size_t __size = static_cast<size_t>(BUFSIZ)) [inline]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 145 of file stdio_filebuf.h.

References basic_filebuf< _CharT, _Traits >::is_open().  

~stdio_filebuf () [inline, virtual]Closes the external data stream if the file descriptor constructor was used.

Definition at line 124 of file stdio_filebuf.h.  

Member Function Documentation

 

basic_filebuf< _CharT, _Traits >::__filebuf_type * close () throw () [inline, 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.

Definition at line 130 of file fstream.tcc.

References basic_filebuf< _CharT, _Traits >::is_open().

Referenced by basic_fstream< _CharT, _Traits >::close(), basic_ofstream< _CharT, _Traits >::close(), basic_ifstream< _CharT, _Traits >::close(), basic_filebuf< _CharT, _Traits >::open(), and basic_filebuf< char_type, traits_type >::~basic_filebuf().  

char_type* eback () const [inline, protected, inherited]

Access to the get area. These functions are only available to other protected functions, including derived classes.

eback() returns the beginning pointer for the input sequence
gptr() returns the next pointer for the input sequence
egptr() returns the end pointer for the input sequence

Definition at line 465 of file streambuf.

Referenced by basic_filebuf< _CharT, _Traits >::imbue(), basic_stringbuf< _CharT, _Traits, _Alloc >::overflow(), basic_stringbuf< _CharT, _Traits, _Alloc >::pbackfail(), basic_filebuf< _CharT, _Traits >::pbackfail(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), basic_filebuf< _CharT, _Traits >::seekoff(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), basic_streambuf< char_type, traits_type >::sputbackc(), basic_streambuf< char_type, traits_type >::sungetc(), basic_filebuf< _CharT, _Traits >::underflow(), and basic_filebuf< _CharT, _Traits >::xsgetn().  

char_type* egptr () const [inline, protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 471 of file streambuf.

Referenced by basic_streambuf< char_type, traits_type >::in_avail(), basic_streambuf< char_type, traits_type >::sbumpc(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), basic_filebuf< _CharT, _Traits >::seekoff(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), basic_streambuf< char_type, traits_type >::sgetc(), basic_stringbuf< _CharT, _Traits, _Alloc >::showmanyc(), basic_filebuf< _CharT, _Traits >::showmanyc(), basic_streambuf< char_type, traits_type >::stossc(), basic_stringbuf< _CharT, _Traits, _Alloc >::str(), basic_stringbuf< _CharT, _Traits, _Alloc >::underflow(), basic_filebuf< _CharT, _Traits >::underflow(), basic_streambuf< _CharT, _Traits >::xsgetn(), and basic_filebuf< _CharT, _Traits >::xsgetn().  

char_type* epptr () const [inline, protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 518 of file streambuf.

Referenced by basic_stringbuf< _CharT, _Traits, _Alloc >::overflow(), basic_streambuf< char_type, traits_type >::sputc(), basic_streambuf< _CharT, _Traits >::xsputn(), and basic_filebuf< _CharT, _Traits >::xsputn().  

int 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 110 of file stdio_filebuf.h.  

std::__c_file* 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 120 of file stdio_filebuf.h.  

void gbump (int __n) [inline, protected, inherited]

Moving the read position. Parameters:

n The delta by which to move.

This just advances the read position without returning any data.

Definition at line 481 of file streambuf.

Referenced by basic_stringbuf< _CharT, _Traits, _Alloc >::pbackfail(), basic_filebuf< _CharT, _Traits >::pbackfail(), basic_streambuf< char_type, traits_type >::sbumpc(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), basic_streambuf< char_type, traits_type >::sputbackc(), basic_streambuf< char_type, traits_type >::stossc(), basic_streambuf< char_type, traits_type >::sungetc(), basic_streambuf< char_type, traits_type >::uflow(), basic_streambuf< _CharT, _Traits >::xsgetn(), and basic_filebuf< _CharT, _Traits >::xsgetn().  

locale getloc () const [inline, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 228 of file streambuf.

Referenced by basic_streambuf< char_type, traits_type >::pubimbue().  

char_type* gptr () const [inline, protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 468 of file streambuf.

Referenced by basic_filebuf< _CharT, _Traits >::imbue(), basic_streambuf< char_type, traits_type >::in_avail(), basic_stringbuf< _CharT, _Traits, _Alloc >::overflow(), basic_stringbuf< _CharT, _Traits, _Alloc >::pbackfail(), basic_filebuf< _CharT, _Traits >::pbackfail(), basic_streambuf< char_type, traits_type >::sbumpc(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), basic_filebuf< _CharT, _Traits >::seekoff(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), basic_streambuf< char_type, traits_type >::sgetc(), basic_stringbuf< _CharT, _Traits, _Alloc >::showmanyc(), basic_filebuf< _CharT, _Traits >::showmanyc(), basic_streambuf< char_type, traits_type >::sputbackc(), basic_streambuf< char_type, traits_type >::stossc(), basic_streambuf< char_type, traits_type >::sungetc(), basic_streambuf< char_type, traits_type >::uflow(), basic_stringbuf< _CharT, _Traits, _Alloc >::underflow(), basic_filebuf< _CharT, _Traits >::underflow(), basic_streambuf< _CharT, _Traits >::xsgetn(), and basic_filebuf< _CharT, _Traits >::xsgetn().  

void imbue (const locale &) [inline, protected, virtual, inherited]

Changes translations. Parameters:

loc A new locale.

Translations done during I/O which depend on the current locale are changed by this call. The standard adds, Between invocations of this function a class derived from streambuf can safely cache results of calls to locale functions and to members of facets so obtained.

Note:

Base class version does nothing.

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 837 of file fstream.tcc.

References ios_base::cur, basic_streambuf< _CharT, _Traits >::eback(), basic_streambuf< _CharT, _Traits >::gptr(), basic_filebuf< _CharT, _Traits >::is_open(), and basic_filebuf< _CharT, _Traits >::seekoff().  

streamsize in_avail () [inline, inherited]

Looking ahead into the stream. Returns:

The number of characters available.

If a read position is available, returns the number of characters available for reading before the buffer must be refilled. Otherwise returns the derived showmanyc().

Definition at line 268 of file streambuf.  

bool is_open () const throw () [inline, inherited]

Returns true if the external file is open.

Definition at line 247 of file fstream.

Referenced by basic_filebuf< _CharT, _Traits >::close(), basic_filebuf< _CharT, _Traits >::imbue(), basic_fstream< _CharT, _Traits >::is_open(), basic_ofstream< _CharT, _Traits >::is_open(), basic_ifstream< _CharT, _Traits >::is_open(), basic_filebuf< _CharT, _Traits >::open(), basic_filebuf< _CharT, _Traits >::seekoff(), basic_filebuf< _CharT, _Traits >::seekpos(), basic_filebuf< _CharT, _Traits >::setbuf(), basic_filebuf< _CharT, _Traits >::showmanyc(), and stdio_filebuf< _CharT, _Traits >::stdio_filebuf().  

basic_filebuf< _CharT, _Traits >::__filebuf_type * open (const char * __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

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 gives the relation between openmode combinations and the equivalent fopen() flags, but the table has not been copied yet.]

Definition at line 96 of file fstream.tcc.

References ios_base::ate, basic_filebuf< _CharT, _Traits >::close(), ios_base::end, basic_filebuf< _CharT, _Traits >::is_open(), and basic_filebuf< _CharT, _Traits >::seekoff().

Referenced by basic_fstream< _CharT, _Traits >::open(), basic_ofstream< _CharT, _Traits >::open(), and basic_ifstream< _CharT, _Traits >::open().  

basic_filebuf< _CharT, _Traits >::int_type overflow (int_type = _Traits::eof()) [inline, protected, virtual, inherited]

Consumes data from the buffer; writes to the controlled sequence. Parameters:

c An additional character to consume.

Returns:

eof() to indicate failure, something else (usually c, or not_eof())

Informally, this function is called when the output buffer is full (or does not exist, as buffering need not actually be done). If a buffer exists, it is 'consumed', with 'some effect' on the controlled sequence. (Typically, the buffer is written out to the sequence verbatim.) In either case, the character c is also written out, if c is not eof().

For a formal definiton of this function, see a good text such as Langer & Kreft, or [27.5.2.4.5]/3-7.

A functioning output streambuf can be created by overriding only this function (no buffer area will be used).

Note:

Base class version does nothing, returns eof().

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 392 of file fstream.tcc.

References ios_base::out, basic_streambuf< _CharT, _Traits >::pbase(), basic_streambuf< _CharT, _Traits >::pbump(), and basic_streambuf< _CharT, _Traits >::pptr().

Referenced by basic_filebuf< _CharT, _Traits >::sync().  

basic_filebuf< _CharT, _Traits >::int_type pbackfail (int_type = _Traits::eof()) [inline, protected, virtual, inherited]

Tries to back up the input sequence. Parameters:

c The character to be inserted back into the sequence.

Returns:

eof() on failure, 'some other value' on success

Postcondition:

The constraints of gptr(), eback(), and pptr() are the same as for underflow().

Note:

Base class version does nothing, returns eof().

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 340 of file fstream.tcc.

References ios_base::cur, basic_streambuf< _CharT, _Traits >::eback(), basic_streambuf< _CharT, _Traits >::gbump(), basic_streambuf< _CharT, _Traits >::gptr(), ios_base::in, basic_filebuf< _CharT, _Traits >::seekoff(), and basic_filebuf< _CharT, _Traits >::underflow().  

char_type* pbase () const [inline, protected, inherited]

Access to the put area. These functions are only available to other protected functions, including derived classes.

pbase() returns the beginning pointer for the output sequence
pptr() returns the next pointer for the output sequence
epptr() returns the end pointer for the output sequence

Definition at line 512 of file streambuf.

Referenced by basic_stringbuf< _CharT, _Traits, _Alloc >::overflow(), basic_filebuf< _CharT, _Traits >::overflow(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), basic_stringbuf< _CharT, _Traits, _Alloc >::str(), basic_filebuf< _CharT, _Traits >::sync(), and basic_filebuf< _CharT, _Traits >::xsputn().  

void pbump (int __n) [inline, protected, inherited]

Moving the write position. Parameters:

n The delta by which to move.

This just advances the write position without returning any data.

Definition at line 528 of file streambuf.

Referenced by basic_filebuf< _CharT, _Traits >::overflow(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), basic_streambuf< char_type, traits_type >::sputc(), and basic_streambuf< _CharT, _Traits >::xsputn().  

char_type* pptr () const [inline, protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 515 of file streambuf.

Referenced by basic_stringbuf< _CharT, _Traits, _Alloc >::overflow(), basic_filebuf< _CharT, _Traits >::overflow(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekoff(), basic_stringbuf< _CharT, _Traits, _Alloc >::seekpos(), basic_streambuf< char_type, traits_type >::sputc(), basic_stringbuf< _CharT, _Traits, _Alloc >::str(), basic_filebuf< _CharT, _Traits >::sync(), basic_streambuf< _CharT, _Traits >::xsputn(), and basic_filebuf< _CharT, _Traits >::xsputn().  

locale pubimbue (const locale & __loc) [inline, inherited]

Entry point for imbue(). Parameters:

loc The new locale.

Returns:

The previous locale.

Calls the derived imbue(loc).

Definition at line 211 of file streambuf.  

pos_type pubseekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode __mode = ios_base::in | ios_base::out) [inline, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 245 of file streambuf.  

pos_type pubseekpos (pos_type __sp, ios_base::openmode __mode = ios_base::in | ios_base::out) [inline, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 250 of file streambuf.  

__streambuf_type* pubsetbuf (char_type * __s, streamsize __n) [inline, inherited]

Entry points for derived buffer functions. The public versions of pubfoo dispatch to the protected derived foo member functions, passing the arguments (if any) and returning the result unchanged.

Definition at line 241 of file streambuf.  

int pubsync () [inline, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 255 of file streambuf.

Referenced by basic_istream< _CharT, _Traits >::sync().  

int_type sbumpc () [inline, inherited]

Getting the next character. Returns:

The next character, or eof.

If the input read position is available, returns that character and increments the read pointer, otherwise calls and returns uflow().

Definition at line 300 of file streambuf.

Referenced by basic_istream< _CharT, _Traits >::getline(), basic_istream< _CharT, _Traits >::ignore(), istreambuf_iterator< _CharT, _Traits >::operator++(), std::operator>>(), and basic_streambuf< char_type, traits_type >::snextc().  

basic_filebuf< _CharT, _Traits >::pos_type seekoff (off_type, ios_base::seekdir, ios_base::openmode = ios_base::in | ios_base::out) [inline, protected, virtual, inherited]

Alters the stream positions. Each derived class provides its own appropriate behavior.

Note:

Base class version does nothing, returns a pos_type that represents an invalid stream position.

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 668 of file fstream.tcc.

References ios_base::cur, basic_streambuf< _CharT, _Traits >::eback(), basic_streambuf< _CharT, _Traits >::egptr(), basic_streambuf< _CharT, _Traits >::gptr(), and basic_filebuf< _CharT, _Traits >::is_open().

Referenced by basic_filebuf< _CharT, _Traits >::imbue(), basic_filebuf< _CharT, _Traits >::open(), and basic_filebuf< _CharT, _Traits >::pbackfail().  

basic_filebuf< _CharT, _Traits >::pos_type seekpos (pos_type, ios_base::openmode = ios_base::in | ios_base::out) [inline, protected, virtual, inherited]

Alters the stream positions. Each derived class provides its own appropriate behavior.

Note:

Base class version does nothing, returns a pos_type that represents an invalid stream position.

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 721 of file fstream.tcc.

References ios_base::beg, and basic_filebuf< _CharT, _Traits >::is_open().  

basic_filebuf< _CharT, _Traits >::__streambuf_type * setbuf (char_type * __s, streamsize __n) [inline, 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++/27_io/howto.html#2 for more.

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 641 of file fstream.tcc.

References basic_filebuf< _CharT, _Traits >::is_open().  

void setg (char_type * __gbeg, char_type * __gnext, char_type * __gend) [inline, protected, inherited]

Setting the three read area pointers. Parameters:

gbeg A pointer.
gnext A pointer.
gend A pointer.

Postcondition:

gbeg == eback(), gnext == gptr(), and gend == egptr()

Definition at line 492 of file streambuf.  

void setp (char_type * __pbeg, char_type * __pend) [inline, protected, inherited]

Setting the three write area pointers. Parameters:

pbeg A pointer.
pend A pointer.

Postcondition:

pbeg == pbase(), pbeg == pptr(), and pend == epptr()

Definition at line 538 of file streambuf.  

int_type sgetc () [inline, inherited]

Getting the next character. Returns:

The next character, or eof.

If the input read position is available, returns that character, otherwise calls and returns underflow(). Does not move the read position after fetching the character.

Definition at line 322 of file streambuf.

Referenced by basic_istream< _CharT, _Traits >::get(), basic_istream< _CharT, _Traits >::getline(), basic_istream< _CharT, _Traits >::ignore(), sentry::sentry(), and basic_streambuf< char_type, traits_type >::snextc().  

streamsize sgetn (char_type * __s, streamsize __n) [inline, inherited]

Entry point for xsgetn. Parameters:

s A buffer area.
n A count.

Returns xsgetn(s,n). The effect is to fill s[0] through s[n-1] with characters from the input sequence, if possible.

Definition at line 341 of file streambuf.  

streamsize showmanyc () [inline, protected, virtual, inherited]

Investigating the data available. Returns:

An estimate of the number of characters available in the input sequence, or -1.

If it returns a positive value, then successive calls to underflow() will not return traits::eof() until at least that number of characters have been supplied. If showmanyc() returns -1, then calls to underflow() or uflow() will fail. [27.5.2.4.3]/1

Note:

Base class version does nothing, returns zero.

The standard adds that the intention is not only that the calls [to underflow or uflow] will not return eof() but that they will return 'immediately'.

The standard adds that 'the morphemes of @c showmanyc are
         'es-how-many-see', not 'show-manic. 

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 165 of file fstream.tcc.

References ios_base::binary, basic_streambuf< _CharT, _Traits >::egptr(), basic_streambuf< _CharT, _Traits >::gptr(), ios_base::in, and basic_filebuf< _CharT, _Traits >::is_open().  

int_type snextc () [inline, inherited]

Getting the next character. Returns:

The next character, or eof.

Calls sbumpc(), and if that function returns traits::eof(), so does this function. Otherwise, sgetc().

Definition at line 282 of file streambuf.

Referenced by basic_istream< _CharT, _Traits >::get(), basic_istream< _CharT, _Traits >::getline(), basic_istream< _CharT, _Traits >::ignore(), and sentry::sentry().  

int_type sputbackc (char_type __c) [inline, inherited]

Pushing characters back into the input stream. Parameters:

c The character to push back.

Returns:

The previous character, if possible.

Similar to sungetc(), but c is pushed onto the stream instead of 'the previous character'. If successful, the next character fetched from the input stream will be c.

Definition at line 355 of file streambuf.

Referenced by std::operator>>(), and basic_istream< _CharT, _Traits >::putback().  

int_type sputc (char_type __c) [inline, inherited]

Entry point for all single-character output functions. Parameters:

c A character to output.

Returns:

c, if possible.

One of two public output functions.

If a write position is available for the output sequence (i.e., the buffer is not full), stores c in that position, increments the position, and returns traits::to_int_type(c). If a write position is not available, returns overflow(c).

Definition at line 407 of file streambuf.

Referenced by basic_istream< _CharT, _Traits >::get(), ostreambuf_iterator< _CharT, _Traits >::operator=(), and basic_stringbuf< _CharT, _Traits, _Alloc >::overflow().  

streamsize sputn (const char_type * __s, streamsize __n) [inline, inherited]

Entry point for all single-character output functions. Parameters:

s A buffer read area.
n A count.

One of two public output functions.

Returns xsputn(s,n). The effect is to write s[0] through s[n-1] to the output sequence, if possible.

Definition at line 433 of file streambuf.  

void stossc () [inline, inherited]

Tosses a character. Advances the read pointer, ignoring the character that would have been read.

See http://gcc.gnu.org/ml/libstdc++/2002-05/msg00168.html

Note:

This function has been deprecated by the standard. You must define _GLIBCXX_DEPRECATED to make this visible; see c++config.h.

Definition at line 769 of file streambuf.  

int_type sungetc () [inline, inherited]

Moving backwards in the input stream. Returns:

The previous character, if possible.

If a putback position is available, this function decrements the input pointer and returns that character. Otherwise, calls and returns pbackfail(). The effect is to 'unget' the last character 'gotten'.

Definition at line 380 of file streambuf.

Referenced by basic_istream< _CharT, _Traits >::unget().  

int sync () [inline, protected, virtual, inherited]

Synchronizes the buffer arrays with the controlled sequences. Returns:

-1 on failure.

Each derived class provides its own appropriate behavior, including the definition of 'failure'.

Note:

Base class version does nothing, returns zero.

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 820 of file fstream.tcc.

References basic_filebuf< _CharT, _Traits >::overflow(), basic_streambuf< _CharT, _Traits >::pbase(), and basic_streambuf< _CharT, _Traits >::pptr().  

virtual int_type uflow () [inline, protected, virtual, inherited]

Fetches more data from the controlled sequence. Returns:

The first character from the pending sequence.

Informally, this function does the same thing as underflow(), and in fact is required to call that function. It also returns the new character, like underflow() does. However, this function also moves the read position forward by one.

Reimplemented in stdio_sync_filebuf< _CharT, _Traits >.

Definition at line 683 of file streambuf.

Referenced by basic_streambuf< char_type, traits_type >::sbumpc(), basic_streambuf< char_type, traits_type >::stossc(), and basic_streambuf< _CharT, _Traits >::xsgetn().  

basic_filebuf< _CharT, _Traits >::int_type underflow () [inline, protected, virtual, inherited]

Fetches more data from the controlled sequence. Returns:

The first character from the pending sequence.

Informally, this function is called when the input buffer is exhausted (or does not exist, as buffering need not actually be done). If a buffer exists, it is 'refilled'. In either case, the next available character is returned, or traits::eof() to indicate a null pending sequence.

For a formal definiton of the pending sequence, see a good text such as Langer & Kreft, or [27.5.2.4.3]/7-14.

A functioning input streambuf can be created by overriding only this function (no buffer area will be used). For an example, see http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#6

Note:

Base class version does nothing, returns eof().

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 191 of file fstream.tcc.

References std::copy(), basic_streambuf< _CharT, _Traits >::eback(), basic_streambuf< _CharT, _Traits >::egptr(), basic_streambuf< _CharT, _Traits >::gptr(), __codecvt_abstract_base< _InternT, _ExternT, _StateT >::in(), ios_base::in, and std::min().

Referenced by basic_filebuf< _CharT, _Traits >::pbackfail().  

streamsize xsgetn (char_type * __s, streamsize __n) [inline, protected, virtual, inherited]

Multiple character extraction. Parameters:

s A buffer area.
n Maximum number of characters to assign.

Returns:

The number of characters assigned.

Fills s[0] through s[n-1] with characters from the input sequence, as if by sbumpc(). Stops when either n characters have been copied, or when traits::eof() would be copied.

It is expected that derived classes provide a more efficient implementation by overriding this definition.

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 511 of file fstream.tcc.

References std::copy(), basic_streambuf< _CharT, _Traits >::eback(), basic_streambuf< _CharT, _Traits >::egptr(), basic_streambuf< _CharT, _Traits >::gbump(), basic_streambuf< _CharT, _Traits >::gptr(), ios_base::in, and basic_streambuf< char_type, traits_type >::xsgetn().  

streamsize xsputn (const char_type * __s, streamsize __n) [inline, protected, virtual, inherited]

Multiple character insertion. Parameters:

s A buffer area.
n Maximum number of characters to write.

Returns:

The number of characters written.

Writes s[0] through s[n-1] to the output sequence, as if by sputc(). Stops when either n characters have been copied, or when sputc() would return traits::eof().

It is expected that derived classes provide a more efficient implementation by overriding this definition.

Reimplemented from basic_streambuf< _CharT, _Traits >.

Definition at line 594 of file fstream.tcc.

References basic_streambuf< _CharT, _Traits >::epptr(), std::min(), ios_base::out, basic_streambuf< _CharT, _Traits >::pbase(), basic_streambuf< _CharT, _Traits >::pptr(), and basic_streambuf< char_type, traits_type >::xsputn().  

Member Data Documentation

 

locale _M_buf_locale [protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 194 of file streambuf.

Referenced by basic_filebuf< _CharT, _Traits >::basic_filebuf(), basic_streambuf< char_type, traits_type >::getloc(), and basic_streambuf< char_type, traits_type >::pubimbue().  

char_type* _M_in_beg [protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 182 of file streambuf.

Referenced by basic_streambuf< char_type, traits_type >::eback(), and basic_streambuf< char_type, traits_type >::setg().  

char_type* _M_in_cur [protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 183 of file streambuf.

Referenced by basic_streambuf< char_type, traits_type >::gbump(), basic_streambuf< char_type, traits_type >::gptr(), and basic_streambuf< char_type, traits_type >::setg().  

char_type* _M_in_end [protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 184 of file streambuf.

Referenced by basic_streambuf< char_type, traits_type >::egptr(), and basic_streambuf< char_type, traits_type >::setg().  

char_type* _M_out_beg [protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 185 of file streambuf.

Referenced by basic_streambuf< char_type, traits_type >::pbase(), and basic_streambuf< char_type, traits_type >::setp().  

char_type* _M_out_cur [protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 186 of file streambuf.

Referenced by basic_streambuf< char_type, traits_type >::pbump(), basic_streambuf< char_type, traits_type >::pptr(), and basic_streambuf< char_type, traits_type >::setp().  

char_type* _M_out_end [protected, inherited]

Locale access. Returns:

The current locale in effect.

If pubimbue(loc) has been called, then the most recent loc is returned. Otherwise the global locale in effect at the time of construction is returned.

Definition at line 187 of file streambuf.

Referenced by basic_streambuf< char_type, traits_type >::epptr(), and basic_streambuf< char_type, traits_type >::setp().

 

Author

Generated automatically by Doxygen for libstdc++ from the source code.


 

Index

NAME
SYNOPSIS
Public Types
Public Member Functions
Protected Member Functions
Protected Attributes
Friends
Detailed Description
template<typename _CharT, typename _Traits = std::char_traits<_CharT>> class __gnu_cxx::stdio_filebuf< _CharT, _Traits >
Member Typedef Documentation
typedef basic_streambuf<char_type, traits_type> __streambuf_type [inherited]
typedef _CharT char_typeThese are standard types. They permit a standardized way of referring to names of (or names dependant on) the template parameters, which are specific to the implementation.
typedef traits_type::int_type int_type
typedef traits_type::off_type off_type
typedef traits_type::pos_type pos_type
typedef _Traits traits_type
Constructor & Destructor Documentation
stdio_filebuf () [inline]deferred initialization
stdio_filebuf (int __fd, std::ios_base::openmode __mode, size_t __size = static_cast<size_t>(BUFSIZ)) [inline]Parameters:
stdio_filebuf (std::__c_file * __f, std::ios_base::openmode __mode, size_t __size = static_cast<size_t>(BUFSIZ)) [inline]Parameters:
~stdio_filebuf () [inline, virtual]Closes the external data stream if the file descriptor constructor was used.
Member Function Documentation
basic_filebuf< _CharT, _Traits >::__filebuf_type * close () throw () [inline, inherited]
char_type* eback () const [inline, protected, inherited]
char_type* egptr () const [inline, protected, inherited]
char_type* epptr () const [inline, protected, inherited]
int fd () [inline]Returns:
std::__c_file* file () [inline]Returns:
void gbump (int __n) [inline, protected, inherited]
locale getloc () const [inline, inherited]
char_type* gptr () const [inline, protected, inherited]
void imbue (const locale &) [inline, protected, virtual, inherited]
streamsize in_avail () [inline, inherited]
bool is_open () const throw () [inline, inherited]
basic_filebuf< _CharT, _Traits >::__filebuf_type * open (const char * __s, ios_base::openmode __mode) [inline, inherited]
basic_filebuf< _CharT, _Traits >::int_type overflow (int_type = _Traits::eof()) [inline, protected, virtual, inherited]
basic_filebuf< _CharT, _Traits >::int_type pbackfail (int_type = _Traits::eof()) [inline, protected, virtual, inherited]
char_type* pbase () const [inline, protected, inherited]
void pbump (int __n) [inline, protected, inherited]
char_type* pptr () const [inline, protected, inherited]
locale pubimbue (const locale & __loc) [inline, inherited]
pos_type pubseekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode __mode = ios_base::in | ios_base::out) [inline, inherited]
pos_type pubseekpos (pos_type __sp, ios_base::openmode __mode = ios_base::in | ios_base::out) [inline, inherited]
__streambuf_type* pubsetbuf (char_type * __s, streamsize __n) [inline, inherited]
int pubsync () [inline, inherited]
int_type sbumpc () [inline, inherited]
basic_filebuf< _CharT, _Traits >::pos_type seekoff (off_type, ios_base::seekdir, ios_base::openmode = ios_base::in | ios_base::out) [inline, protected, virtual, inherited]
basic_filebuf< _CharT, _Traits >::pos_type seekpos (pos_type, ios_base::openmode = ios_base::in | ios_base::out) [inline, protected, virtual, inherited]
basic_filebuf< _CharT, _Traits >::__streambuf_type * setbuf (char_type * __s, streamsize __n) [inline, protected, virtual, inherited]
void setg (char_type * __gbeg, char_type * __gnext, char_type * __gend) [inline, protected, inherited]
void setp (char_type * __pbeg, char_type * __pend) [inline, protected, inherited]
int_type sgetc () [inline, inherited]
streamsize sgetn (char_type * __s, streamsize __n) [inline, inherited]
streamsize showmanyc () [inline, protected, virtual, inherited]
int_type snextc () [inline, inherited]
int_type sputbackc (char_type __c) [inline, inherited]
int_type sputc (char_type __c) [inline, inherited]
streamsize sputn (const char_type * __s, streamsize __n) [inline, inherited]
void stossc () [inline, inherited]
int_type sungetc () [inline, inherited]
int sync () [inline, protected, virtual, inherited]
virtual int_type uflow () [inline, protected, virtual, inherited]
basic_filebuf< _CharT, _Traits >::int_type underflow () [inline, protected, virtual, inherited]
streamsize xsgetn (char_type * __s, streamsize __n) [inline, protected, virtual, inherited]
streamsize xsputn (const char_type * __s, streamsize __n) [inline, protected, virtual, inherited]
Member Data Documentation
locale _M_buf_locale [protected, inherited]
char_type* _M_in_beg [protected, inherited]
char_type* _M_in_cur [protected, inherited]
char_type* _M_in_end [protected, inherited]
char_type* _M_out_beg [protected, inherited]
char_type* _M_out_cur [protected, inherited]
char_type* _M_out_end [protected, inherited]
Author

This document was created by man2html, using the manual pages.
Time: 22:37:27 GMT, April 16, 2011