HP-UX Reference (11i v1 00/12) - 3 Library Functions N-Z (vol 7)

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STANDARD Printed by: Nora Chuang [nchuang] STANDARD

/build/1111/BRICK/man3/nan.3m

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wcstod(3C) wcstod(3C)

NAME

wcstod() - convert wide character string to double-precision number

SYNOPSIS

#include <wchar.h>

double wcstod(const wchar_t *nptr, wchar_t **endptr);

Remarks:

This function is compliant with the XPG4 Worldwide Portability Interface wide-character formatting

functions. It parallels the 8-bit character formatting function deﬁned in strtod(3C).

DESCRIPTION

wcstod() returns, as a double-precision ﬂoating-point number, the value represented by the wide charac-

ter string pointed to by nptr. The wide character string is scanned (leading white-space characters as

deﬁned by iswspace() in wctype(3C) are ignored) up to the ﬁrst unrecognized character. If no conver-

sion can take place, zero is returned.

wcstod() recognizes wide characters in the following sequence:

1. An optional string of ‘‘white-space’’ wide characters which are ignored,

2. An optional sign,

3. A string of digits optionally containing a radix character,

4. An optional e or E followed by an optional sign or space, followed by an integer.

The radix character is determined by the current NLS environment (see setlocale(3C)). If setlocale()

has not been called successfully, the default

NLS environment, "C", is used (see lang(5)). The default

environment speciﬁes a period (.) as the radix character.

If the value of endptr is not

(wchar_t **)NULL, the variable to which it points is set to point at the

wide character after the last number, if any, that was recognized. If no number can be formed,

*endptr is

set to nptr, and zero is returned.

The deﬁnition for this function and the type

wchar_t are provided in the <wchar.h>header.

APPLICATION USAGE

wcstod() is thread-safe and async-cancel-safe.

EXTERNAL INFLUENCES

Locale

The LC_NUMERIC category determines the value of the radix character within the currently loaded NLS

environment.

The LC_CTYPE category determines how wide character codes are interpreted.

International Code Set Support

Single- and multi-byte character code sets are supported.

RETURN VALUE

If the correct value would cause overﬂow, +HUGE_VAL or -HUGE_VAL 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.

If wcstod() encounters an input wide character string equal to inf or infinity (both case insensi-

tive) it will return HUGE_VAL.Ifwcstod() encounters an input wide character string equal to nan

(case insensitive) it will return _DNANQ.

AUTHOR

wcstod() was developed by AT&T and HP.