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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.1‐2017 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 <hyphen-minus>, 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 locale, additional locale-specific subject sequence forms 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 values, {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 ALSO

       fscanf(), iswalpha(), wcstod(), wcstol()

       The Base Definitions volume of POSIX.1‐2017, <wchar.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1-2017,  Standard  for  Information Technology -- Portable Operating System Interface
       (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C)  2018  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 .

       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 .