/*** *fstream.cpp - * * Copyright (c) 1991-1997, Microsoft Corporation. All rights reserved. * *Purpose: * Contains the member functions for the fstream class. * *******************************************************************************/ #include #include #include #include #include #include #include #include #include #pragma hdrstop #include /*** *fstream::fstream() - fstream default constructor * *Purpose: * Default constructor for fstream objects. * *Entry: * None. * *Exit: * None. * *Exceptions: * *******************************************************************************/ fstream::fstream() : iostream(_new_crt filebuf) { istream::delbuf(1); ostream::delbuf(1); } /*** *fstream::fstream(const char * name, int mode, int prot) - fstream constructor * *Purpose: * Constructor for fstream objects. Creates an associated filebuf object, * opens a named file and attaches it to the new filebuf. * *Entry: * name = filename to open. * mode = see filebuf::open mode argument * prot = see filebuf::open share argument * *Exit: * None. * *Exceptions: * Sets failbit if open fails. * *******************************************************************************/ fstream::fstream(const char * name, int mode, int prot) : iostream(_new_crt filebuf) { istream::delbuf(1); ostream::delbuf(1); if (!(rdbuf()->open(name, mode, prot))) { istream::state = istream::failbit; ostream::state = ostream::failbit; } } /*** *fstream::fstream(filedesc fd) - fstream constructor * *Purpose: * Constructor for fstream objects. Creates an associated filebuf object * and attaches it to the given file descriptor. * *Entry: * fd = file descriptor of file previously opened using _open or _sopen. * *Exit: * None. * *Exceptions: * *******************************************************************************/ fstream::fstream(filedesc _fd) : iostream(_new_crt filebuf(_fd)) { istream::delbuf(1); ostream::delbuf(1); } /*** *fstream::fstream(filedesc fd, char * sbuf, int len) - fstream constructor * *Purpose: * Constructor for fstream objects. Creates an associated filebuf object * and attaches it to the given file descriptor. Filebuf object uses * user-supplied buffer or is unbuffered if sbuf or len = 0. * *Entry: * fd = file descriptor of file previously opened using _open or _sopen. * sbuf = pointer to character buffer or NULL if request for unbuffered. * len = lenght of character buffer sbuf or 0 if request for unbuffered. * *Exit: * None. * *Exceptions: * *******************************************************************************/ fstream::fstream(filedesc _fd, char * sbuf, int len) : iostream(_new_crt filebuf(_fd, sbuf, len)) { istream::delbuf(1); ostream::delbuf(1); } /*** *fstream::~fstream() - fstream destructor * *Purpose: * fstream destructor. * *Entry: * None. * *Exit: * None. * *Exceptions: * *******************************************************************************/ fstream::~fstream() { } /*** *streambuf* fstream::setbuf(char * ptr, int len) - setbuf function * *Purpose: * fstream setbuf function * *Entry: * ptr = pointer to buffer or NULL for unbuffered. * len = length of buffer or zero for unbuffered. * *Exit: * Returns rdbuf() or NULL if error. * *Exceptions: * If fstream is already open or if rdbuf()->setbuf fails, sets failbit * and returns NULL. * *******************************************************************************/ streambuf * fstream::setbuf(char * ptr, int len) { if ((is_open()) || (!(rdbuf()->setbuf(ptr, len)))) { istream::clear(istream::state | istream::failbit); ostream::clear(ostream::state | ostream::failbit); return NULL; } return rdbuf(); } /*** *void fstream::attach(filedesc _fd) - attach member function * *Purpose: * fstream attach member function. Just calls rdbuf()->attach(). * *Entry: * _fd = file descriptor of previously opened file. * *Exit: * None. * *Exceptions: * Sets failbit if rdbuf()->attach fails. * *******************************************************************************/ void fstream::attach(filedesc _fd) { if (!(rdbuf()->attach(_fd))) { istream::clear(istream::state | istream::failbit); ostream::clear(ostream::state | ostream::failbit); } } /*** *void fstream::open(const char * name, int mode, int prot) - fstream open() * *Purpose: * Opens a named file and attaches it to the associated filebuf. * Just calls rdbuf()->open(). * *Entry: * name = filename to open. * mode = see filebuf::open mode argument * prot = see filebuf::open share argument * *Exit: * None. * *Exceptions: * Sets failbit if already open or rdbuf()->open() fails. * *******************************************************************************/ void fstream::open(const char * name, int mode, int prot) { if (is_open() || !(rdbuf()->open(name, mode, prot))) { istream::clear(istream::state | istream::failbit); ostream::clear(ostream::state | ostream::failbit); } } /*** *void fstream::close() - close member function * *Purpose: * fstream close member function. Just calls rdbuf()->close(). * Clears rdstate() error bits if successful. * *Entry: * None. * *Exit: * None. * *Exceptions: * Sets failbit if rdbuf()->close fails. * *******************************************************************************/ void fstream::close() { if (rdbuf()->close()) { istream::clear(); ostream::clear(); } else { istream::clear(istream::state | istream::failbit); ostream::clear(ostream::state | ostream::failbit); } }