Source code of Windows XP (NT5)
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

250 lines
4.5 KiB

/***
* istream.cpp - definitions for istream and istream_withassign classes
*
* Copyright (c) 1991-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Definitions of member functions for istream and istream_withassign
* classes.
* [AT&T C++]
*
*Revision History:
* 07-15-91 KRS Created.
* 08-15-91 KRS Fix handling of 1-length strings in get(char*,int,int)
* 08-20-91 KRS Make read() not do text translation (for filebufs)
* 08-21-91 KRS Fix >>(streambuf *) to advance pointer properly.
* 08-22-91 KRS Fix octal error in getint().
* 08-26-91 KRS Fix for Windows DLL's and set max. ibuffer[] lengths.
* 09-05-91 KRS Don't special-case 0x in getint(). Spec. conformance...
* 09-10-91 KRS Reinstate text translation (by default) for read().
* 09-12-91 KRS Treat count as unsigned in get() and read().
* 09-16-91 KRS Fix get(char *, int lim, char) for lim=0 case.
* 09-23-91 KRS Split up flie for granularity purposes.
* 10-21-91 KRS Make eatwhite() return void again.
* 10-24-91 KRS Move istream_withassign::operator=(streambuf*) here.
* 11-04-91 KRS Make constructors work with virtual base.
* Fix whitespace error handling in ipfx().
* 11-20-91 KRS Add/fix copy constructor and assignment operators.
* 01-23-92 KRS C700 #5883: Fix behaviour of peek() to call ipfx(1).
* 03-28-95 CFW Fix debug delete scheme.
* 03-21-95 CFW Remove _delete_crt.
* 06-14-95 CFW Comment cleanup.
*
*******************************************************************************/
#include <cruntime.h>
#include <internal.h>
#include <stdlib.h>
#include <ctype.h>
#include <iostream.h>
#include <dbgint.h>
#pragma hdrstop
istream::istream()
// : ios()
{
x_flags |= ios::skipws;
x_gcount = 0;
_fGline = 0;
}
istream::istream(streambuf* _inistbf)
// : ios()
{
init(_inistbf);
x_flags |= ios::skipws;
x_gcount = 0;
_fGline = 0;
}
istream::istream(const istream& _istrm)
// : ios()
{
init(_istrm.rdbuf());
x_flags |= ios::skipws;
x_gcount = 0;
_fGline = 0;
}
istream::~istream()
// : ~ios()
{
}
// used by ios::sync_with_stdio()
istream& istream::operator=(streambuf * _sbuf)
{
if (delbuf() && rdbuf())
delete rdbuf();
bp = 0;
this->ios::operator=(ios()); // initialize ios members
delbuf(0); // important!
init(_sbuf); // set up bp
x_flags |= ios::skipws; // init istream members too
x_gcount = 0;
return *this;
}
int istream::ipfx(int need)
{
lock();
if (need) // reset gcount if unformatted input
x_gcount = 0;
if (state) // return 0 iff error condition
{
state |= ios::failbit; // solves cin>>buf problem
unlock();
return 0;
}
if (x_tie && ((need==0) || (need > bp->in_avail())))
{
x_tie->flush();
}
lockbuf();
if ((need==0) && (x_flags & ios::skipws))
{
eatwhite();
if (state) // eof or error
{
state |= ios::failbit;
unlockbuf();
unlock();
return 0;
}
}
// leave locked ; isfx() will unlock
return 1; // return nz if okay
}
// formatted input functions
istream& istream::operator>>(char * s)
{
int c;
unsigned int i, lim;
if (ipfx(0))
{
lim = (unsigned)(x_width-1);
x_width = 0;
if (!s)
{
state |= ios::failbit;
}
else
{
for (i=0; i< lim; i++)
{
c=bp->sgetc();
if (c==EOF)
{
state |= ios::eofbit;
if (!i)
state |= ios::failbit|ios::badbit;
break;
}
else if (isspace(c))
{
break;
}
else
{
s[i] = (char)c;
bp->stossc(); // advance pointer
}
}
if (!i)
state |= ios::failbit;
else
s[i] = '\0';
}
isfx();
}
return *this;
}
int istream::peek()
{
int retval;
if (ipfx(1))
{
retval = (bp->sgetc());
isfx();
}
else
retval = EOF;
return retval;
}
istream& istream::putback(char c)
{
if (good())
{
lockbuf();
if (bp->sputbackc(c)==EOF)
{
clear(state | ios::failbit);
}
unlockbuf();
}
return *this;
}
int istream::sync()
{
int retval;
lockbuf();
if ((retval=bp->sync())==EOF)
{
clear(state | (ios::failbit|ios::badbit));
}
unlockbuf();
return retval;
}
void istream::eatwhite()
{
int c;
lockbuf();
c = bp->sgetc();
for ( ; ; )
{
if (c==EOF)
{
clear(state | ios::eofbit);
break;
}
if (isspace(c))
{
c = bp->snextc();
}
else
{
break;
}
}
unlockbuf();
}
istream_withassign::istream_withassign()
: istream()
{
}
istream_withassign::istream_withassign(streambuf* _is)
: istream(_is)
{
}
istream_withassign::~istream_withassign()
// : ~istream()
{
}