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/***
* istrgdbl.cxx - definitions for istream class core double routine
*
* Copyright (c) 1991-1992, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Definitions of member function for istream getdouble().
* [AT&T C++]
*
*Revision History:
* 09-26-91 KRS Created. Split off from istream.cxx for granularity.
*
*******************************************************************************/
#include <cruntime.h>
#include <internal.h>
#include <ctype.h>
#include <iostream.h>
#pragma hdrstop
/***
*int istream::getdouble(char * buffer, int buflen) - get a double
*
*Purpose:
* Get a double from stream.
*
*Entry:
* char * buffer = area for number to be copied.
* int buflen = max. length of buffer
*
*Exit:
* Returns 0 if fatal error
* Otherwise, returns length of buffer filled.
* Sets ios::failbit on error forming number.
* If successful, buffer[] contains the number, followed by \0.
*
*Exceptions:
*
*******************************************************************************/
int istream::getdouble(char * buffer, int buflen) // returns length
{
int c;
int i = 0;
int fDigit = 0; // true if legal digit encountered
int fDecimal=0; // true if '.' encountered or no longer valid
int fExp=0; // true if 'E' or 'e' encounted
if (ipfx(0))
{
c=bp->sgetc();
for (; i<buflen; buffer[i] = (char)c,c=bp->snextc(),i++)
{
if (c==EOF)
{
state |= ios::eofbit;
break;
}
if ((!i) || (fExp==1))
{
if ((c=='-') || (c=='+'))
{
continue;
}
}
// UNDONE: use locale-dependent decimal point character!!!
if ((c=='.') && (!fExp) && (!fDecimal))
{
fDecimal++;
continue;
}
if (((c=='E') || (c=='e')) && (!fExp))
{
fDecimal++; // can't allow decimal now
fExp++;
continue;
}
if (!isdigit(c))
break;
if (fExp)
fExp++;
else
fDigit++;
}
if (fExp==1) // E or e with no number after it
{
if (bp->sputbackc(buffer[i])!=EOF)
{
i--;
state &= ~(ios::eofbit);
}
else
{
state |= ios::failbit; // CONSIDER: correct?
}
}
if ((!fDigit) || (i==buflen))
state |= ios::failbit;
// buffer contains a valid number or '\0'
buffer[i] = '\0';
isfx();
}
// UNDONE: check for errors, return EOF
return i;
}
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