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WCSTOUL(3P) POSIX Programmer's Manual WCSTOUL(3P)
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.
wcstoul, wcstoull — convert a wide-character string to an unsigned
long
#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 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
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.
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.
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.
fscanf(3p), iswalpha(3p), wcstod(3p), wcstol(3p)
The Base Definitions volume of POSIX.1‐2008, wchar.h(0p)
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 Electrical 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.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 WCSTOUL(3P)
Pages that refer to this page: wchar.h(0p), fwscanf(3p), wcstoimax(3p)