123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596 |
- /*
- * strtod.c - This file is part of the libc-8086 package for ELKS,
- * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with this library; if not, write to the Free
- * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- */
- #include <stdlib.h>
- #include <ctype.h>
- float
- strtod(const char *nptr, char ** endptr)
- {
- unsigned short negative;
- float number;
- float fp_part;
- int exponent;
- unsigned short exp_negative;
- /* advance beyond any leading whitespace */
- while (isspace(*nptr))
- nptr++;
- /* check for optional '+' or '-' */
- negative=0;
- if (*nptr=='-')
- {
- negative=1;
- nptr++;
- }
- else
- if (*nptr=='+')
- nptr++;
- number=0;
- while (isdigit(*nptr))
- {
- number=number*10+(*nptr-'0');
- nptr++;
- }
- if (*nptr=='.')
- {
- nptr++;
- fp_part=0;
- while (isdigit(*nptr))
- {
- fp_part=fp_part/10.0 + (*nptr-'0')/10.0;
- nptr++;
- }
- number+=fp_part;
- }
- if (*nptr=='e' || *nptr=='E')
- {
- nptr++;
- exp_negative=0;
- if (*nptr=='-')
- {
- exp_negative=1;
- nptr++;
- }
- else
- if (*nptr=='+')
- nptr++;
- exponent=0;
- while (isdigit(*nptr))
- {
- exponent=exponent*10+(*nptr-'0');
- exponent++;
- }
- }
- while (exponent)
- {
- if (exp_negative)
- number/=10;
- else
- number*=10;
- exponent--;
- }
- return (negative ? -number:number);
- }
|