Originální popis anglicky:
wcstoul, wcstoull - convert a wide-character string to an unsigned long
Návod, kniha: POSIX Programmer's Manual
#include <wchar.h>
unsigned long wcstoul(const wchar_t *restrict
nptr,
wchar_t **restrict
endptr , int base);
unsigned long long wcstoull(const wchar_t *restrict
nptr,
wchar_t **restrict
endptr , int base);
The
wcstoul() and
wcstoull() functions shall convert the initial
portion of the wide-character string pointed to by
nptr to
unsigned
long and
unsigned long long representation, respectively. First,
they shall decompose the input wide-character string into three parts:
- 1.
- An initial, possibly empty, sequence of white-space
wide-character codes (as specified by iswspace())
- 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 unrecognized
wide-character codes, including the terminating null wide-character code
of the input wide-character string
Then they shall attempt to convert the subject sequence to an unsigned integer,
and return the result.
If
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 shall be permitted. If the value of
base is 16, the
wide-character codes 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 wide-character code that is not
white space and 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 codes, or if the first wide-character
code that is not white space is other than a sign or a permissible letter or
digit.
If the subject sequence has the expected form and
base is 0, the sequence
of wide-character codes starting with the first digit shall be interpreted as
an integer constant. If the subject sequence has the expected form and the
value of
base is between 2 and 36, it shall be 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
shall be negated. A pointer to the final wide-character string shall be stored
in the object pointed to by
endptr, provided that
endptr is not
a null pointer.
In other than the C or POSIX locales, other implementation-defined
subject sequences may be accepted.
If the subject sequence is empty or does not have the expected form, no
conversion shall be performed; the value of
nptr shall be stored in the
object pointed to by
endptr, provided that
endptr is not a null
pointer.
The
wcstoul() function shall not change the setting of
errno if
successful.
Since 0, {ULONG_MAX}, and {ULLONG_MAX} are returned on error and 0 is also a
valid return on success, an application wishing to check for error situations
should set
errno to 0, then call
wcstoul() or
wcstoull(),
then check
errno.
Upon successful completion, the
wcstoul() and
wcstoull() functions
shall return the converted value, if any. If no conversion could be performed,
0 shall be returned and
errno may be set to indicate the error.
If the correct value is outside the range of representable values, {ULONG_MAX}
or {ULLONG_MAX} respectively shall be returned and
errno set to
[ERANGE].
These functions shall 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.
The following sections are informative.
None.
None.
None.
None.
iswalpha() ,
scanf() ,
wcstod() ,
wcstol() , the
Base Definitions volume of IEEE Std 1003.1-2001,
<wchar.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
