WCSTOL(3C) Standard C Library Functions WCSTOL(3C)
NAME
wcstol, wcstoll, wstol, watol, watoll, watoi - convert wide character
string to long integer
SYNOPSIS
#include <wchar.h>
long wcstol(
const wchar_t *restrict nptr,
wchar_t **restrict endptr,
int base);
long long wcstoll(
const wchar_t *restrict nptr,
wchar_t **restrict endptr,
int base);
#include <widec.h>
long wstol(
const wchar_t *nptr,
wchar_t **endptr,
int base);
long watol(
wchar_t *nptr);
long long watoll(
wchar_t *nptr);
int watoi(
wchar_t *nptr);
DESCRIPTION
The
wcstol() and
wcstoll() functions convert the initial portion of
the wide character string pointed to by
nptr to
long and
long long representation, respectively. They first decompose the input string
into three parts:
1. an initial, possibly empty, sequence of white-space wide-
character codes (as specified by
iswspace(3C))
2. a subject sequence interpreted as an integer represented
in some radix determined by the value of
base 3. a final wide character string of one or more unrecognised
wide character codes, including the terminating null wide-
character code of the input wide character string
They then attempt to convert the subject sequence to an integer, and
return the result.
If the value of
base is
0, the expected form of the subject sequence
is that of a decimal constant, octal constant or hexadecimal
constant, any of which may be preceded by a `+' or `-' sign. A
decimal constant begins with a non-zero digit, and consists of a
sequence of decimal digits. An octal constant consists of the prefix
`0' optionally followed by a sequence of the digits `0' to `7' only.
A hexadecimal constant consists of the prefix `0x' or `0X' followed
by a sequence of the decimal digits and letters `a' (or `A') to `f'
(or `F') with values 10 to 15 respectively.
If the value of
base is between
2 and
36, the expected form of the
subject sequence is a sequence of letters and digits representing an
integer with the radix specified by
base, optionally preceded by a
`+' or `-' sign, but not including an integer suffix. The letters
from `a' (or `A') to `z' (or `Z') inclusive are ascribed the values
10 to 35; only letters whose ascribed values are less than that of
base are permitted. If the value of
base is
16, the wide-character
code representations of `0x' or `0X' may optionally precede the
sequence of letters and digits, following the sign if present.
The subject sequence is defined as the longest initial subsequence of
the input wide character string, starting with the first non-white-
space wide-character code, that is of the expected form. The subject
sequence contains no wide-character codes if the input wide character
string is empty or consists entirely of white-space wide-character
code, or if the first non-white-space wide-character code is other
than a sign or a permissible letter or digit.
If the subject sequence has the expected form and the value of
base is
0, the sequence of wide-character codes starting with the first
digit is interpreted as an integer constant. If the subject sequence
has the expected form and the value of
base is between
2 and
36, it
is used as the base for conversion, ascribing to each letter its
value as given above. If the subject sequence begins with a minus
sign (-), the value resulting from the conversion is negated. A
pointer to the final wide character string is stored in the object
pointed to by
endptr, provided that
endptr is not a null pointer.
If the subject sequence is empty or does not have the expected form,
no conversion is performed; the value of
nptr is stored in the object
pointed to by
endptr, provided that
endptr is not a null pointer.
These functions do not change the setting of
errno if successful.
Since 0, {
LONG_MIN} or {
LLONG_MIN}, and {
LONG_MAX} or {
LLONG_MAX} are
returned on error and are also valid returns on success, an
application wanting to check for error situations should set
errno to
0, call one of these functions, then check
errno.
The
wstol() function is equivalent to
wcstol().
The
watol() function is equivalent to
wstol(str,(wchar_t **)NULL, 10). The
watoll() function is the long-long (double long) version of
watol().
The
watoi() function is equivalent to
(int)watol().
RETURN VALUES
Upon successful completion, these functions return the converted
value, if any. If no conversion could be performed, 0 is returned
and
errno may be set to indicate the error. If the correct value is
outside the range of representable values, {
LONG_MIN}, {
LONG_MAX},
{
LLONG_MIN}, or {
LLONG_MAX} is returned (according to the sign of the
value), and
errno is set to
ERANGE.
ERRORS
These functions will fail if:
EINVAL The value of
base is not supported.
ERANGE The value to be returned is not representable.
These functions may fail if:
EINVAL No conversion could be performed.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+--------------------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+--------------------------------------+
|Interface Stability |
wcstol() and
wcstoll() are Standard. |
+--------------------+--------------------------------------+
|MT-Level | MT-Safe |
+--------------------+--------------------------------------+
SEE ALSO
iswalpha(3C),
iswspace(3C),
scanf(3C),
wcstod(3C),
attributes(7),
standards(7)NOTES
Truncation from
long long to
long can take place upon assignment or
by an explicit cast.
November 1, 2003 WCSTOL(3C)
