strtod(3C)          (C Programming Language Utilities)           strtod(3C)


   NAME
         strtod, atof, - convert string to double-precision number

   SYNOPSIS
         #include <stdlib.h>

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

         double atof (const char *nptr);

   DESCRIPTION
         strtod returns as a double-precision floating-point number the value
         represented by the character string pointed to by nptr.  The string
         is scanned up to the first unrecognized character.

         strtod recognizes an optional string of ``white-space'' characters
         [as defined by isspace in ctype(3C)], then an optional sign, then a
         string of digits optionally containing a decimal point character,
         then an optional exponent part including an e or E followed by an
         optional sign, followed by an integer.

         If the value of endptr is not (char **)NULL, a pointer to the
         character terminating the scan is returned in the location pointed to
         by endptr.  If no number can be formed, *endptr is set to nptr, and
         zero is returned.

         atof(nptr) is equivalent to:
               strtod(nptr, (char **)NULL).

   SEE ALSO
         ctype(3C), scanf(3S), strtol(3C).

   DIAGNOSTICS
         If the correct value would cause overflow, +HUGE is returned
         (according to the sign of the value), and errno is set to ERANGE.
         If the correct value would cause underflow, zero is returned and
         errno is set to ERANGE.
         When the -Xc or -Xa compilation options are used, HUGE_VAL is
         returned instead of HUGE.














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