and
.I long double
representation, respectively.
-
+.PP
The expected form of the (initial portion of the) string is
optional leading white space as recognized by
.BR isspace (3),
way the type of NAN (see NOTES).
.SH RETURN VALUE
These functions return the converted value, if any.
-
+.PP
If
.I endptr
is not NULL,
a pointer to the character after the last character used in the conversion
is stored in the location referenced by
.IR endptr .
-
+.PP
If no conversion is performed, zero is returned and (unless
.I endptr
is null) the value of
.I nptr
is stored in the location referenced by
.IR endptr .
-
+.PP
If the correct value would cause overflow, plus or minus
.B HUGE_VAL
.RB ( HUGE_VALF ,
.TE
.SH CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99.
-
+.PP
.BR strtod ()
was also described in C89.
.SH NOTES
and then determine if an error occurred by checking whether
.I errno
has a nonzero value after the call.
-
+.PP
In the glibc implementation, the
.IR n-char-sequence
that optionally follows "NAN"