stdio_filebuf.h revision 303975
11839Swollman// File descriptor layer for filebuf -*- C++ -*- 21839Swollman 31839Swollman// Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc. 41839Swollman// 51839Swollman// This file is part of the GNU ISO C++ Library. This library is free 61839Swollman// software; you can redistribute it and/or modify it under the 71839Swollman// terms of the GNU General Public License as published by the 88858Srgrimes// Free Software Foundation; either version 2, or (at your option) 91839Swollman// any later version. 1013771Smpp 111839Swollman// This library is distributed in the hope that it will be useful, 128858Srgrimes// but WITHOUT ANY WARRANTY; without even the implied warranty of 131839Swollman// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 141839Swollman// GNU General Public License for more details. 151839Swollman 161839Swollman// You should have received a copy of the GNU General Public License along 171839Swollman// with this library; see the file COPYING. If not, write to the Free 181839Swollman// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 191839Swollman// USA. 201839Swollman 211839Swollman// As a special exception, you may use this file as part of a free software 221839Swollman// library without restriction. Specifically, if other files instantiate 231839Swollman// templates or use macros or inline functions from this file, or you compile 241839Swollman// this file and link it with other files to produce an executable, this 251839Swollman// file does not by itself cause the resulting executable to be covered by 261839Swollman// the GNU General Public License. This exception does not however 271839Swollman// invalidate any other reasons why the executable file might be covered by 281903Swollman// the GNU General Public License. 298858Srgrimes 301903Swollman/** @file ext/stdio_filebuf.h 3121059Speter * This file is a GNU extension to the Standard C++ Library. 321839Swollman */ 331839Swollman 341839Swollman#ifndef _STDIO_FILEBUF_H 351839Swollman#define _STDIO_FILEBUF_H 1 361839Swollman 371839Swollman#pragma GCC system_header 381839Swollman 391839Swollman#include <fstream> 401903Swollman 411903Swollman_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 421839Swollman 431839Swollman /** 441839Swollman * @brief Provides a layer of compatibility for C/POSIX. 451839Swollman * 461839Swollman * This GNU extension provides extensions for working with standard C 471839Swollman * FILE*'s and POSIX file descriptors. It must be instantiated by the 481839Swollman * user with the type of character used in the file stream, e.g., 491839Swollman * stdio_filebuf<char>. 501839Swollman */ 511839Swollman template<typename _CharT, typename _Traits = std::char_traits<_CharT> > 521839Swollman class stdio_filebuf : public std::basic_filebuf<_CharT, _Traits> 531839Swollman { 541839Swollman public: 551839Swollman // Types: 561839Swollman typedef _CharT char_type; 571839Swollman typedef _Traits traits_type; 581839Swollman typedef typename traits_type::int_type int_type; 598858Srgrimes typedef typename traits_type::pos_type pos_type; 601839Swollman typedef typename traits_type::off_type off_type; 611839Swollman typedef std::size_t size_t; 626685Sphk 636685Sphk public: 646685Sphk /** 651839Swollman * deferred initialization 661839Swollman */ 671839Swollman stdio_filebuf() : std::basic_filebuf<_CharT, _Traits>() {} 681839Swollman 691839Swollman /** 701839Swollman * @param fd An open file descriptor. 711839Swollman * @param mode Same meaning as in a standard filebuf. 721839Swollman * @param size Optimal or preferred size of internal buffer, in chars. 731839Swollman * 741839Swollman * This constructor associates a file stream buffer with an open 751839Swollman * POSIX file descriptor. The file descriptor will be automatically 761839Swollman * closed when the stdio_filebuf is closed/destroyed. 771839Swollman */ 781839Swollman stdio_filebuf(int __fd, std::ios_base::openmode __mode, 791839Swollman size_t __size = static_cast<size_t>(BUFSIZ)); 801839Swollman 811839Swollman /** 821839Swollman * @param f An open @c FILE*. 831903Swollman * @param mode Same meaning as in a standard filebuf. 841903Swollman * @param size Optimal or preferred size of internal buffer, in chars. 851903Swollman * Defaults to system's @c BUFSIZ. 861903Swollman * 8721059Speter * This constructor associates a file stream buffer with an open 881903Swollman * C @c FILE*. The @c FILE* will not be automatically closed when the 891903Swollman * stdio_filebuf is closed/destroyed. 9021059Speter */ 9121059Speter stdio_filebuf(std::__c_file* __f, std::ios_base::openmode __mode, 9221059Speter size_t __size = static_cast<size_t>(BUFSIZ)); 931903Swollman 941839Swollman /** 951903Swollman * Closes the external data stream if the file descriptor constructor 96 * was used. 97 */ 98 virtual 99 ~stdio_filebuf(); 100 101 /** 102 * @return The underlying file descriptor. 103 * 104 * Once associated with an external data stream, this function can be 105 * used to access the underlying POSIX file descriptor. Note that 106 * there is no way for the library to track what you do with the 107 * descriptor, so be careful. 108 */ 109 int 110 fd() { return this->_M_file.fd(); } 111 112 /** 113 * @return The underlying FILE*. 114 * 115 * This function can be used to access the underlying "C" file pointer. 116 * Note that there is no way for the library to track what you do 117 * with the file, so be careful. 118 */ 119 std::__c_file* 120 file() { return this->_M_file.file(); } 121 }; 122 123 template<typename _CharT, typename _Traits> 124 stdio_filebuf<_CharT, _Traits>::~stdio_filebuf() 125 { } 126 127 template<typename _CharT, typename _Traits> 128 stdio_filebuf<_CharT, _Traits>:: 129 stdio_filebuf(int __fd, std::ios_base::openmode __mode, size_t __size) 130 { 131 this->_M_file.sys_open(__fd, __mode); 132 if (this->is_open()) 133 { 134 this->_M_mode = __mode; 135 this->_M_buf_size = __size; 136 this->_M_allocate_internal_buffer(); 137 this->_M_reading = false; 138 this->_M_writing = false; 139 this->_M_set_buffer(-1); 140 } 141 } 142 143 template<typename _CharT, typename _Traits> 144 stdio_filebuf<_CharT, _Traits>:: 145 stdio_filebuf(std::__c_file* __f, std::ios_base::openmode __mode, 146 size_t __size) 147 { 148 this->_M_file.sys_open(__f, __mode); 149 if (this->is_open()) 150 { 151 this->_M_mode = __mode; 152 this->_M_buf_size = __size; 153 this->_M_allocate_internal_buffer(); 154 this->_M_reading = false; 155 this->_M_writing = false; 156 this->_M_set_buffer(-1); 157 } 158 } 159 160_GLIBCXX_END_NAMESPACE 161 162#endif 163