strtod(3C)                     DG/UX R4.11MU05                    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).


   Considerations for Threads Programming
                     +---------+-----------------------------+
                     |         |                      async- |
                     |function | reentrant   cancel   cancel |
                     |         |             point     safe  |
                     +---------+-----------------------------+
                     |atof     |     Y         N        N    |
                     |strtod   |     Y         N        N    |
                     +---------+-----------------------------+

SEE ALSO
       reentrant(3), 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, HUGEVAL is
       returned instead of HUGE.


Licensed material--property of copyright holder(s)