HP-UX Reference (11i v1 05/09) - 3 Library Functions N-Z (vol 7)

nan(3M) nan(3M)

NAME

nan() - string-to-NaN conversion function

SYNOPSIS

#include <math.h>

double nan(const char *tagp);

DESCRIPTION

The nan() function creates a quiet NaN from the speciﬁed string. The call

nan("n-char-sequence")

is equivalent to strtod("NAN( n-char-sequence)", (char**) NULL).

The call

nan("") is

equivalent to

strtod("NAN()", (char**) NULL).

If tagp does not point to an n-char-sequence

string, the result NaN’s content is unspeciﬁed.

The ISO/ANSI C committee has approved the

nan() function for inclusion in the C9X draft standard.

To use this function, compile either with the default

-Ae option or with the -Aa and -D_HPUX_SOURCE

options. Make sure your program includes <

math.h>. Link in the math library by specifying -lm on the

compiler or linker command line.

RETURN VALUE

The

nan() function returns a quiet NaN.

ERRORS

No errors are deﬁned.