1 // Iostreams wrapper for stdio FILE* -*- C++ -*-
3 // Copyright (C) 2003, 2004 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 2, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING. If not, write to the Free
18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction. Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License. This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
30 /** @file ext/stdiostream.h
31 * This file is a GNU extension to the Standard C++ Library.
34 #ifndef _STDIO_SYNC_FILEBUF_H
35 #define _STDIO_SYNC_FILEBUF_H 1
37 #pragma GCC system_header
43 #ifdef _GLIBCXX_USE_WCHAR_T
49 template<typename _CharT, typename _Traits = std::char_traits<_CharT> >
50 class stdio_sync_filebuf : public std::basic_streambuf<_CharT, _Traits>
54 typedef _CharT char_type;
55 typedef _Traits traits_type;
56 typedef typename traits_type::int_type int_type;
57 typedef typename traits_type::pos_type pos_type;
58 typedef typename traits_type::off_type off_type;
61 // Underlying stdio FILE
62 std::__c_file* const _M_file;
64 // Last character gotten. This is used when pbackfail is
65 // called from basic_streambuf::sungetc()
66 int_type _M_unget_buf;
70 stdio_sync_filebuf(std::__c_file* __f)
71 : _M_file(__f), _M_unget_buf(traits_type::eof())
75 * @return The underlying FILE*.
77 * This function can be used to access the underlying "C" file pointer.
78 * Note that there is no way for the library to track what you do
79 * with the file, so be careful.
82 file() { return this->_M_file; }
89 syncungetc(int_type __c);
92 syncputc(int_type __c);
97 int_type __c = this->syncgetc();
98 return this->syncungetc(__c);
104 // Store the gotten character in case we need to unget it.
105 _M_unget_buf = this->syncgetc();
110 pbackfail(int_type __c = traits_type::eof())
113 const int_type __eof = traits_type::eof();
115 // Check if the unget or putback was requested
116 if (traits_type::eq_int_type(__c, __eof)) // unget
118 if (!traits_type::eq_int_type(_M_unget_buf, __eof))
119 __ret = this->syncungetc(_M_unget_buf);
120 else // buffer invalid, fail.
124 __ret = this->syncungetc(__c);
126 // The buffered character is no longer valid, discard it.
127 _M_unget_buf = __eof;
131 virtual std::streamsize
132 xsgetn(char_type* __s, std::streamsize __n);
135 overflow(int_type __c = traits_type::eof())
138 if (traits_type::eq_int_type(__c, traits_type::eof()))
140 if (std::fflush(_M_file))
141 __ret = traits_type::eof();
143 __ret = traits_type::not_eof(__c);
146 __ret = this->syncputc(__c);
150 virtual std::streamsize
151 xsputn(const char_type* __s, std::streamsize __n);
155 { return std::fflush(_M_file); }
157 virtual std::streampos
158 seekoff(std::streamoff __off, std::ios_base::seekdir __dir,
159 std::ios_base::openmode = std::ios_base::in | std::ios_base::out)
161 std::streampos __ret(std::streamoff(-1));
163 if (__dir == std::ios_base::beg)
165 else if (__dir == std::ios_base::cur)
169 #ifdef _GLIBCXX_USE_LFS
170 if (!fseeko64(_M_file, __off, __whence))
171 __ret = std::streampos(ftello64(_M_file));
173 if (!fseek(_M_file, __off, __whence))
174 __ret = std::streampos(std::ftell(_M_file));
179 virtual std::streampos
180 seekpos(std::streampos __pos,
181 std::ios_base::openmode __mode =
182 std::ios_base::in | std::ios_base::out)
183 { return seekoff(std::streamoff(__pos), std::ios_base::beg, __mode); }
187 inline stdio_sync_filebuf<char>::int_type
188 stdio_sync_filebuf<char>::syncgetc()
189 { return std::getc(_M_file); }
192 inline stdio_sync_filebuf<char>::int_type
193 stdio_sync_filebuf<char>::syncungetc(int_type __c)
194 { return std::ungetc(__c, _M_file); }
197 inline stdio_sync_filebuf<char>::int_type
198 stdio_sync_filebuf<char>::syncputc(int_type __c)
199 { return std::putc(__c, _M_file); }
202 inline std::streamsize
203 stdio_sync_filebuf<char>::xsgetn(char* __s, std::streamsize __n)
205 std::streamsize __ret = std::fread(__s, 1, __n, _M_file);
207 _M_unget_buf = traits_type::to_int_type(__s[__ret - 1]);
209 _M_unget_buf = traits_type::eof();
214 inline std::streamsize
215 stdio_sync_filebuf<char>::xsputn(const char* __s, std::streamsize __n)
216 { return std::fwrite(__s, 1, __n, _M_file); }
218 #ifdef _GLIBCXX_USE_WCHAR_T
220 inline stdio_sync_filebuf<wchar_t>::int_type
221 stdio_sync_filebuf<wchar_t>::syncgetc()
222 { return std::getwc(_M_file); }
225 inline stdio_sync_filebuf<wchar_t>::int_type
226 stdio_sync_filebuf<wchar_t>::syncungetc(int_type __c)
227 { return std::ungetwc(__c, _M_file); }
230 inline stdio_sync_filebuf<wchar_t>::int_type
231 stdio_sync_filebuf<wchar_t>::syncputc(int_type __c)
232 { return std::putwc(__c, _M_file); }
235 inline std::streamsize
236 stdio_sync_filebuf<wchar_t>::xsgetn(wchar_t* __s, std::streamsize __n)
238 std::streamsize __ret = 0;
239 const int_type __eof = traits_type::eof();
242 int_type __c = this->syncgetc();
243 if (traits_type::eq_int_type(__c, __eof))
245 __s[__ret] = traits_type::to_char_type(__c);
250 _M_unget_buf = traits_type::to_int_type(__s[__ret - 1]);
252 _M_unget_buf = traits_type::eof();
257 inline std::streamsize
258 stdio_sync_filebuf<wchar_t>::xsputn(const wchar_t* __s,
261 std::streamsize __ret = 0;
262 const int_type __eof = traits_type::eof();
265 if (traits_type::eq_int_type(this->syncputc(*__s++), __eof))
273 #if _GLIBCXX_EXTERN_TEMPLATE
274 extern template class stdio_sync_filebuf<char>;
275 #ifdef _GLIBCXX_USE_WCHAR_T
276 extern template class stdio_sync_filebuf<wchar_t>;
279 } // namespace __gnu_cxx