STRTOD(3C-SVR4)     RISC/os Reference Manual      STRTOD(3C-SVR4)



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 charac-
     ters [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 loca-
     tion 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.














                        Printed 11/19/92                   Page 1