williamr@2: /*
williamr@2:  * Copyright (c) 1999
williamr@2:  * Silicon Graphics Computer Systems, Inc.
williamr@2:  *
williamr@2:  * Copyright (c) 1999 
williamr@2:  * Boris Fomitchev
williamr@2:  *
williamr@2:  * This material is provided "as is", with absolutely no warranty expressed
williamr@2:  * or implied. Any use is at your own risk.
williamr@2:  *
williamr@2:  * Permission to use or copy this software for any purpose is hereby granted 
williamr@2:  * without fee, provided the above notices are retained on all copies.
williamr@2:  * Permission to modify the code and to distribute modified code is granted,
williamr@2:  * provided the above notices are retained, and a notice that the code was
williamr@2:  * modified is included with the above copyright notice.
williamr@2:  *
williamr@2:  */ 
williamr@2: // This header is an extension.  It defines two streambufs:
williamr@2: // stdio_istreambuf, a read-only streambuf synchronized with a C stdio
williamr@2: // FILE object, and stdio_ostreambuf, a write-only streambuf
williamr@2: // synchronized with a C stdio FILE object.  Note that neither 
williamr@2: // stdio_istreambuf nor stdio_ostreambuf is a template; both classes
williamr@2: // are derived from basic_streambuf<char, char_traits<char> >.
williamr@2: 
williamr@2: // Note: the imbue() member function is a no-op.  In particular, these
williamr@2: // classes assume that codecvt<char, char, mbstate_t> is always an identity
williamr@2: // transformation.  This is true of the default locale, and of all locales
williamr@2: // defined for the C I/O library.  If you need to use a locale where 
williamr@2: // the codecvt<char, char, mbstate_t> facet performs a nontrivial 
williamr@2: // conversion, then you should use basic_filebuf<> instead of stdio_istreambuf
williamr@2: // or stdio_ostreambuf.  (If you don't understand what any of this means, 
williamr@2: // then it's not a feature you need to worry about.  Locales where 
williamr@2: // codecvt<char, char, mbstate_t> does something nontrivial are a rare
williamr@2: // corner case.)
williamr@2: 
williamr@2: 
williamr@2: #ifndef _STLP_STDIO_STREAMBUF
williamr@2: #define _STLP_STDIO_STREAMBUF
williamr@2: 
williamr@2: #if !defined(STLP_WINCE)
williamr@2: 
williamr@2: #include <streambuf>            // For basic_streambuf<>
williamr@2: #include <cstdio>              // For FILE.
williamr@2: 
williamr@2: # ifndef _STLP_HAS_NO_NAMESPACES
williamr@2: // This is an extension.  It is in namespace SGI, not namespace std
williamr@2: namespace _SgI {
williamr@2: 
williamr@2: # ifdef _STLP_USE_NAMESPACES
williamr@2: using namespace _STLP_STD;
williamr@2:   // MSVC needs this
williamr@2: using _STLP_STD::streamsize;
williamr@2: using _STLP_STD::streambuf;
williamr@2: using _STLP_STD::basic_streambuf;
williamr@2: using _STLP_STD::ios_base;
williamr@2:   // using _STLP_STD::ios_base::openmode;
williamr@2: # endif
williamr@2: # endif
williamr@2: 
williamr@2: // Base class for features common to stdio_istreambuf and stdio_ostreambuf
williamr@2: class stdio_streambuf_base : public basic_streambuf<char, _STLP_STD::char_traits<char> >
williamr@2: {
williamr@2: public:                         // Constructor, destructor.
williamr@2:   // The argument may not be null.  It must be an open file pointer.
williamr@2:   stdio_streambuf_base(FILE*);
williamr@2: 
williamr@2:   // The destructor flushes the stream, but does not close it.
williamr@2:   ~stdio_streambuf_base();
williamr@2: 
williamr@2: protected:                      // Virtual functions from basic_streambuf.
williamr@2:   streambuf* setbuf(char*, streamsize);
williamr@2: 
williamr@2:   pos_type seekoff(off_type, ios_base::seekdir,
williamr@2:                    ios_base::openmode
williamr@2:                           = ios_base::in | ios_base::out);
williamr@2:   pos_type seekpos(pos_type,
williamr@2:                    ios_base::openmode
williamr@2:                           = ios_base::in | ios_base::out);
williamr@2:   int sync();
williamr@2: 
williamr@2: protected:
williamr@2:   FILE* _M_file;
williamr@2: };
williamr@2: 
williamr@2: class stdio_istreambuf : public stdio_streambuf_base
williamr@2: {
williamr@2: public:                         // Constructor, destructor.
williamr@2:   stdio_istreambuf(FILE* __f) : stdio_streambuf_base(__f) {}
williamr@2: 
williamr@2:   ~stdio_istreambuf();
williamr@2: 
williamr@2: protected:                      // Virtual functions from basic_streambuf.
williamr@2:   streamsize showmanyc();
williamr@2:   int_type underflow();
williamr@2:   int_type uflow();
williamr@2:   virtual int_type pbackfail(int_type c = traits_type::eof());
williamr@2: };
williamr@2: 
williamr@2: class stdio_ostreambuf : public stdio_streambuf_base
williamr@2: {
williamr@2: public:                         // Constructor, destructor.
williamr@2:   stdio_ostreambuf(FILE* __f) : stdio_streambuf_base(__f) {}
williamr@2:   ~stdio_ostreambuf();
williamr@2: 
williamr@2: protected:                      // Virtual functions from basic_streambuf.
williamr@2:   streamsize showmanyc();
williamr@2:   int_type overflow(int_type c = traits_type::eof());
williamr@2: };
williamr@2: 
williamr@2: # ifndef _STLP_HAS_NO_NAMESPACES
williamr@2: } // Close namespace _SgI.
williamr@2: # endif
williamr@2: 
williamr@2: #endif /* _STLP_STDIO_STREAMBUF */
williamr@2: 
williamr@2: #endif /* _STLP_WINCE */
williamr@2: 
williamr@2: // Local Variables:
williamr@2: // mode:C++
williamr@2: // End:
williamr@2: