(BSD System Compatibility)

decimal_to_floating(3bsd)

decimal_to_floating: decimal_to_single, decimal_to_double, decimal_to_extended -- (BSD) convert decimal record to floating-point value

Synopsis

   /usr/ucb/cc [flag . . . ] file . . .
   
   #include <fp.h>
   

   void decimal_to_single(single *px,
   	decimal_mode *pm, decimal_record *pd,
   	fp_exception_field_type *ps);
   

   void decimal_to_double(double *px,
   	decimal_mode *pm, decimal_record *pd,
   	fp_exception_field_type *ps);
   

   void decimal_to_extended(extended *px,
   	decimal_mode *pm, decimal_record *pd,
   	fp_exception_field_type *ps);

Description

The decimal_to_floating functions convert the decimal record at *pd into a floating-point value at *px, observing the modes specified in *pm and setting exceptions in *ps. If there are no IEEE exceptions, *ps will be zero.

pd->sign and pd->fpclass are always taken into account. pd->exponent and pd->ds are used when pd->fpclass is fp_normal or fp_subnormal. In these cases pd->ds must contain one or more ASCII digits followed by a NULL. *px is set to a correctly rounded approximation to

   (pd->sign)*(pd->ds)*10**(pd->exponent)

Thus if pd->exponent == -2 and pd->ds == "1234", *px will get 12.34 rounded to storage precision. pd->ds cannot have more than DECIMAL_STRING_LENGTH-1 significant digits because one character is used to terminate the string with a NULL. If pd->more!= on input then additional nonzero digits follow those in pd->ds; fp_inexact is set accordingly on output in *ps.

*px is correctly rounded according to the IEEE rounding modes in pm->rd. *ps is set to contain fp_inexact, fp_underflow, or fp_overflow if any of these arise.

pd->ndigits, pm->df, and pm->ndigits are not used.

References

fscanf(3S), strtod(3C)

Note: Most applications should use sprintf [see fprintf(3S)], strtod(3C) and strtold [see strtod(3C)] instead of these functions.