NAME

       strtod - convert ASCII string to double

SYNOPSIS

       #include <stdlib.h>

       double strtod(const char *nptr, char **endptr);

DESCRIPTION

       The  strtod()  function  converts  the initial portion of the string pointed to by nptr to
       double representation.

       The expected form of the string is optional leading white space as checked by  isspace(3),
       an optional plus (``+'') or minus sign (``-'') followed by a sequence of digits optionally
       containing a decimal-point character, optionally followed by  an  exponent.   An  exponent
       consists  of  an ``E'' or ``e'', followed by an optional plus or minus sign, followed by a
       non-empty sequence of digits.  If the locale is not "C" or "POSIX", different formats  may
       be used.

RETURN VALUES

       The strtod function returns the converted value, if any.

       If  endptr  is  not  NULL, a pointer to the character after the last character used in the
       conversion is stored in the location referenced by endptr.

       If no conversion is performed, zero is returned and the value of nptr  is  stored  in  the
       location referenced by endptr.

       If  the  correct value would cause overflow, plus or minus HUGE_VAL is returned (according
       to the sign of the value), and ERANGE is stored in errno.   If  the  correct  value  would
       cause underflow, zero is returned and ERANGE is stored in errno.

ERRORS

       ERANGE Overflow or underflow occurred.

CONFORMING TO

       ANSI C

SEE ALSO

       atof(3), atoi(3), atol(3), strtol(3), strtoul(3)