/***
*ifstream.cxx - ifstream member function definitions
*
* Copyright (c) 1991-1992, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Contains the member functions for the ifstream class.
*
*Revision History:
* 09-21-91 KRS Created. Split up fstream.cxx for granularity.
* 10-22-91 KRS C700 #4883: fix error status for ifstream::open().
*
*******************************************************************************/
#include <cruntime.h>
#include <internal.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys\types.h>
#include <io.h>
#include <fstream.h>
#pragma hdrstop
#include <sys\stat.h>
/***
*ifstream::ifstream() - ifstream default constructor
*
*Purpose:
* Default constructor for ifstream objects.
*
*Entry:
* None.
*
*Exit:
* None.
*
*Exceptions:
*
*******************************************************************************/
ifstream::ifstream()
: istream(new filebuf)
{
delbuf(1); // schedule automatic deletion too...
// CONSIDER: do anything else?
}
/***
*ifstream::ifstream(const char * name, int mode, int prot) - ifstream ctor
*
*Purpose:
* Constructor for ifstream 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. ios::in is implied.
* prot = see filebuf::open share argument
*
*Exit:
* None.
*
*Exceptions:
* Sets failbit if open fails.
*
*******************************************************************************/
ifstream::ifstream(const char * name, int mode, int prot)
: istream(new filebuf)
{
delbuf(1); // schedule automatic deletion too...
if (!(rdbuf()->open(name, (mode|ios::in), prot)))
state |= ios::failbit;
}
/***
*ifstream::ifstream(filedesc fd) - ifstream constructor
*
*Purpose:
* Constructor for ifstream 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:
*
*******************************************************************************/
ifstream::ifstream(filedesc _fd)
: istream(new filebuf(_fd))
{
delbuf(1);
}
/***
*ifstream::ifstream(filedesc fd, char * sbuf, int len) - ifstream constructor
*
*Purpose:
* Constructor for ifstream 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:
*
*******************************************************************************/
ifstream::ifstream(filedesc _fd, char * sbuf, int len)
: istream(new filebuf(_fd, sbuf, len))
//: istream(new filebuf);
{
delbuf(1);
}
/***
*ifstream::~ifstream() - ifstream destructor
*
*Purpose:
* ifstream destructor.
*
*Entry:
* None.
*
*Exit:
* None.
*
*Exceptions:
*
*******************************************************************************/
ifstream::~ifstream()
{
// CONSIDER: do anything else?
}
/***
*streambuf* ifstream::setbuf(char * ptr, int len) - setbuf function
*
*Purpose:
* ifstream 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 ifstream is already open or if rdbuf()->setbuf fails, sets failbit
* and returns NULL.
*
*******************************************************************************/
streambuf * ifstream::setbuf(char * ptr, int len)
{
if ((is_open()) || (!(rdbuf()->setbuf(ptr, len))))
{
clear(state | ios::failbit);
return NULL;
}
// UNDONE: turn off output buffer??
return rdbuf();
}
/***
*void ifstream::attach(filedesc _fd) - attach member function
*
*Purpose:
* ifstream 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 ifstream::attach(filedesc _fd) // CONSIDER: inline?
{
if (!(rdbuf()->attach(_fd)))
clear(state | ios::failbit);
}
/***
*void ifstream::open(const char * name, int mode, int prot) - ifstream 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. ios::in is implied.
* prot = see filebuf::open share argument
*
*Exit:
* None.
*
*Exceptions:
* Sets failbit if already open or rdbuf()->open() fails.
*
*******************************************************************************/
void ifstream::open(const char * name, int mode, int prot)
{
if (is_open() || !(rdbuf()->open(name, (mode|ios::in), prot)))
clear(state | ios::failbit);
}
/***
*void ifstream::close() - close member function
*
*Purpose:
* ifstream 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 ifstream::close()
{
clear((rdbuf()->close()) ? 0 : (state | ios::failbit));
}
