WCSTOUL(3P) POSIX Programmer's Manual WCSTOUL(3P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAME
wcstoul, wcstoull — convert a wide-character string to an unsigned long
SYNOPSIS
#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);
DESCRIPTION
The functionality described on this reference page is aligned with the
ISO C standard. Any conflict between the requirements described here
and the ISO C standard is unintentional. This volume of POSIX.1‐2008
defers to the ISO C standard.
The wcstoul() and wcstoull() functions shall convert the initial por‐
tion 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 let‐
ters '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 sub‐
ject sequence is a sequence of letters and digits representing an inte‐
ger 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 per‐
mitted. 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 sub‐
ject 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.
These functions 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.
RETURN VALUE
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 val‐
ues, {ULONG_MAX} or {ULLONG_MAX} respectively shall be returned and
errno set to [ERANGE].
ERRORS
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.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSOfscanf(), iswalpha(), wcstod(), wcstol()
The Base Definitions volume of POSIX.1‐2008, <wchar.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 WCSTOUL(3P)
