source: trunk/minix/lib/fphook/fphook.c@ 20

/*
 * fltpr.c - print floating point numbers
 */
/* $Header: /cvsup/minix/src/lib/fphook/fphook.c,v 1.1.1.1 2005/04/21 14:56:11 beng Exp $ */

#ifndef NOFLOAT
#include        <string.h>
#include        <stdarg.h>
#include        "../stdio/loc_incl.h"
int _fp_hook = 1;

static char *
_pfloat(long double r, register char *s, int n, int flags)
{
        register char *s1;
        int sign, dp;
        register int i;

        s1 = _fcvt(r, n, &dp, &sign);
        if (sign)
                *s++ = '-';
        else if (flags & FL_SIGN)
                *s++ = '+';
        else if (flags & FL_SPACE)
                *s++ = ' ';

        if (dp<=0)
                *s++ = '0';
        for (i=dp; i>0; i--)
                if (*s1) *s++ = *s1++;
                else *s++ = '0';
        if (((i=n) > 0) || (flags & FL_ALT))
                *s++ = '.';
        while (++dp <= 0) {
                if (--i<0)
                        break;
                *s++ = '0';
        }
        while (--i >= 0)
                if (*s1) *s++ = *s1++;
                else *s++ = '0';
        return s;
}

static char *
_pscien(long double r, register char *s, int n, int flags)
{
        int sign, dp; 
        register char *s1;

        s1 = _ecvt(r, n + 1, &dp, &sign);
        if (sign)
                *s++ = '-';
        else if (flags & FL_SIGN)
                *s++ = '+';
        else if (flags & FL_SPACE)
                *s++ = ' ';

        *s++ = *s1++;
        if ((n > 0) || (flags & FL_ALT))
                *s++ = '.';
        while (--n >= 0)
                if (*s1) *s++ = *s1++;
                else *s++ = '0';
        *s++ = 'e';
        if ( r != 0 ) --dp ;
        if ( dp<0 ) {
                *s++ = '-' ; dp= -dp ;
        } else {
                *s++ = '+' ;
        }
        if (dp >= 100) {
                *s++ = '0' + (dp / 100);
                dp %= 100;
        }
        *s++ = '0' + (dp/10);
        *s++ = '0' + (dp%10);
        return s;
}

#define NDIGINEXP(exp)          (((exp) >= 100 || (exp) <= -100) ? 3 : 2)
#define LOW_EXP                 -4
#define USE_EXP(exp, ndigits)   (((exp) < LOW_EXP + 1) || (exp >= ndigits + 1))

static char *
_gcvt(long double value, int ndigit, char *s, int flags)
{
        int sign, dp;
        register char *s1, *s2;
        register int i;
        register int nndigit = ndigit;

        s1 = _ecvt(value, ndigit, &dp, &sign);
        s2 = s;
        if (sign) *s2++ = '-';
        else if (flags & FL_SIGN)
                *s2++ = '+';
        else if (flags & FL_SPACE)
                *s2++ = ' ';

        if (!(flags & FL_ALT))
                for (i = nndigit - 1; i > 0 && s1[i] == '0'; i--)
                        nndigit--;

        if (USE_EXP(dp,ndigit)) {
                /* Use E format */
                dp--;
                *s2++ = *s1++;
                if ((nndigit > 1) || (flags & FL_ALT)) *s2++ = '.';
                while (--nndigit > 0) *s2++ = *s1++;
                *s2++ = 'e';
                if (dp < 0) {
                        *s2++ = '-';
                        dp = -dp;
                }
                else     *s2++ = '+';
                s2 += NDIGINEXP(dp);
                *s2 = 0;
                for (i = NDIGINEXP(dp); i > 0; i--) {
                        *--s2 = dp % 10 + '0';
                        dp /= 10;
                }
                return s;
        }
        /* Use f format */
        if (dp <= 0) {
                if (*s1 != '0') {
                        /* otherwise the whole number is 0 */
                        *s2++ = '0';
                        *s2++ = '.';
                }
                while (dp < 0) {
                        dp++;
                        *s2++ = '0';
                }
        }
        for (i = 1; i <= nndigit; i++) {
                *s2++ = *s1++;
                if (i == dp) *s2++ = '.';
        }
        if (i <= dp) {
                while (i++ <= dp) *s2++ = '0';
                *s2++ = '.';
        }
        if ((s2[-1]=='.') && !(flags & FL_ALT)) s2--;
        *s2 = '\0';
        return s;
}

char *
_f_print(va_list *ap, int flags, char *s, char c, int precision)
{
        register char *old_s = s;
        long double ld_val;

        if (flags & FL_LONGDOUBLE) ld_val = va_arg(*ap, long double);
        else ld_val = (long double) va_arg(*ap, double);

        switch(c) {
        case 'f':
                s = _pfloat(ld_val, s, precision, flags);
                break;
        case 'e':
        case 'E':
                s = _pscien(ld_val, s, precision , flags);
                break;
        case 'g':
        case 'G':
                s = _gcvt(ld_val, precision, s, flags);
                s += strlen(s);
                break;
        }
        if ( c == 'E' || c == 'G') {
                while (*old_s && *old_s != 'e') old_s++;
                if (*old_s == 'e') *old_s = 'E';
        }
        return s;
}
#endif  /* NOFLOAT */
/* $Header: /cvsup/minix/src/lib/fphook/fphook.c,v 1.1.1.1 2005/04/21 14:56:11 beng Exp $ */

#include <stdlib.h>
#include "../ansi/ext_fmt.h"

void _str_ext_cvt(const char *s, char **ss, struct EXTEND *e);
double _ext_dbl_cvt(struct EXTEND *e);

double
strtod(const char *p, char **pp)
{
        struct EXTEND e;

        _str_ext_cvt(p, pp, &e);
        return _ext_dbl_cvt(&e);
}